# Is Pyrex all right for one use?



## alchemy_cake (Jul 5, 2017)

Hey all,

I thought I was ready to make my first little batch, and my lye is finally arriving this afternoon. I did tons of research - but somehow until now I managed to miss the fact that Pyrex is weakened by lye. I think it was because in all the cp-making videos I watched, the demonstrators used Pyrex (or even, in some cases, glass jars!). I believe I have seen Pyrex recommended in lists of required supplies as well.

I've been waiting for a long time until I felt prepared to do this, so of course I'm impatient, but I also want to be safe. I probably won't be able to go and get stainless steel bowls until the weekend. In your honest opinions, do you think I could make my first small batch using my Pyrex, and thereafter only use my Pyrex for safer stuff such as mixing body butters or infusing oils?

I'm honestly not sure how much of a risk it would be. Obviously I'm hoping you'll say it'll be fine, but if the general consensus is 'no', then I will bow to your greater knowledge and wait until I can get the stainless steel.

Thank you all for your advice!

- Laurence


----------



## toxikon (Jul 5, 2017)

My comment may get some grimaces, but I use my Pyrex bowl for my oils and batter mixing. I make my lye solution in a safe plastic jug, but I do pour my lye solution into my Pyrex bowl to mix with my oils. I've been using the same Pyrex bowl for years without issue. The batter is only in my Pyrex bowl for a max of 15-30 minutes while I stickblend and pour. It's then wiped out with paper towel and immediately washed and dried. It still looks brand new, I don't see any etching. I know I may be pushing my luck and I've heard the horror stories, but I've never had an issue.


----------



## kchaystack (Jul 5, 2017)

I would not use stainless steel either, I would use plastic with a recycle 2 or 5 number on it.  I use these:

http://www.homedepot.com/p/HDX-1-qt-Multi-Mix-Pail-2M3/202264024

you can get them at wal-mart or anywhere that has a paint area.


----------



## BrewerGeorge (Jul 5, 2017)

toxikon said:


> My comment may get some grimaces, but I use my Pyrex bowl for my oils and batter mixing. I make my lye solution in a safe plastic jug, but I do pour my lye solution into my Pyrex bowl to mix with my oils. I've been using the same Pyrex bowl for years without issue. The batter is only in my Pyrex bowl for a max of 15-30 minutes while I stickblend and pour. It's then wiped out with paper towel and immediately washed and dried. It still looks brand new, I don't see any etching. I know I may be pushing my luck and I've heard the horror stories, but I've never had an issue.



Fully prepared for the flaming, I do exactly the same thing.  I know it's not best practice and I don't recommend it for anyone else, but I feel safe enough doing it.

ETA: In re-reading, I want to emphasize that my comment was not meant as a go-ahead for Lawrence to use pyrex. I do things in very specific ways to minimize potential problems with the pyrex - I assume toxikon does too.  If you're not very clear on those things, you could make a mistake.  So I'd recommend going to a hardware store and getting a 1 gallon plastic paint mixing bucket with a 2 or 5 recycling number for your first batch, Laurence.


----------



## penelopejane (Jul 5, 2017)

For one use Pyrex is ok. 

I too use no. 5 or 2 plastic for everything soap related.  It's cheap, light, safe and easy to use. It also comes in a huge array of sizes.


----------



## dixiedragon (Jul 5, 2017)

I do it occasionally too. It's not a good idea to do it all the time, but a few times isn't a big deal.


----------



## earlene (Jul 5, 2017)

My understanding of Pyrex is that it used to be made with a better grade of glass and that is safe to use with lye.  Borosilicate glass was used in the production of Pyrex, but is no longer used.  Therefore, if your Pyrex is older, then it should be fine.  If it is the newer soda lime glass, then continued use would be ill-advised.

See this article for more on Pyrex and when it was changed.  http://www.worldkitchen.com/en/the-truth-about-pyrex-test.html


----------



## alchemy_cake (Jul 5, 2017)

So far, the consensus seems to be that using the heat-safe plastics are a good alternative, and that for one time I should be okay with the Pyrex. I have some mixing bowls with a rubberized bottom that might be appropriate, in which case I needn't worry about the Pyrex at all. I've seen plastic suggested before too, but the source that warned about Pyrex also said that stainless steel was the safest. (I will try to dig the thread up again so that I can share it here. Maybe plastic was suggested, and I missed it?) I really don't like working with steel, though, so plastic is my preference if Pyrex isn't safe. 

Pyrex does seem to be used a LOT by experienced soapers, despite the risk! I guess it's probably since it's so sturdy, and you can see everything at once. I've been cooking (not professionally) for years, and similarly I know that experienced cooks will take calculated risks that they wouldn't suggest to anyone new to the kitchen.

Earlene, unfortunately, it is all brand-new Pyrex! The old stuff seems to be indestructible. I have some glass mixing bowls and some enameled pots we got from my partner's grandmother that are at least 40 years old, and they're the toughest things. Meanwhile, my expensive new frying pans don't seem to last worth a darn. I hate to sound like a geezer, especially at my age, but it doesn't seem like stuff is built to last any more. :lolno:


----------



## Kittish (Jul 5, 2017)

alchemy_cake said:


> I hate to sound like a geezer, especially at my age, but it doesn't seem like stuff is built to last any more. :lolno:



It isn't, by and large. A consumer-driven economy doesn't work if people don't have to keep buying stuff.


----------



## alchemy_cake (Jul 5, 2017)

Kittish said:


> It isn't, by and large. A consumer-driven economy doesn't work if people don't have to keep buying stuff.



I admit that I like to buy softer soaps because it means I get to buy more sooner!


----------



## BrewerGeorge (Jul 5, 2017)

Ok, in the spirit of informed choice, here's the Why and How.

PYREX (all upper case, usually white) is borosillicate and safe.  However, pyrex (all lower case, usually red) is soda glass and risky.  The problems is strength and thermal expansion.  Borosillicates are strong with low thermal expansion, while soda glass is weak with high thermal expansion.

The way they make soda glass strong enough for general use is through tempering, which is a process of manipulating internal stresses on the glass via differential cooling during manufacture.  But strength is predicated on the object retaining it's original shape and smooth surface.  Scratches or chips will create a flaw in that surface and become an unintended focus point for those internal stresses and any others introduced by heating and cooling.  I don't know if they still make them, but my high school science teacher had a demonstration that illustrated this concept very well.  It was a glass bulb he would use to pound steel nails into boards without breaking, but as soon as he dropped one of those nails _inside_ the bulb and scratched the surface, it would break.  You can also observe this phenomenon in something like a glass door.  A tempered glass door, when struck hard enough, will shatter completely into pebbles of glass, but an untempered door, struck much less hard, will break into jagged shards.  Kitchenware isn't tempered to either of those extremes, but the effect is still in play.

So you start with a pre-stressed object and add heat.  Soda glass is very mobile with temperature; it expands a lot when heated and shrinks a lot when cooled.  Usually that isn't a problem if the whole item is subjected to the same temperatures.  However, when there is a temperature differential among different parts of an item things can get ugly.  The classic example is taking a hot item from the oven and setting it on a cold counter.  The bottom touching the counter cools and compresses too much and too fast compared to the hotter parts on top and the thing shatters.  A similar thing would happen if you tried heating part of a vessel over flame, *or if the bottom part of a cup suddenly rose to 200F because somebody just added NaOH to the water in it.*  Any scratches or etchings will further concentrate those heat stresses, and you could end up with the "bombs" you see on YouTube - only this time with caustic soap solution or lye in it.

You can see why the recommendation is "Don't do it" but if you still decide you want to risk it, you must follow these cautions.  1) Never, EVER mix lye solution in soda glass.  That is the worst-case scenario for all the risks of breakage and consequences if it breaks.  2) Don't microwave it.  Microwave ovens by their nature encourage differential heating based on position in the box and density of the material. Heat your oils in a separate containers. 3) Keep an eye out for etchings and scratches before use.  4) Keep temperatures moderate and always be thinking about temperature differential.  Don't set it on the granite countertop when it's warm, for instance.

Finally, as a slightly-off-topic aside, soda glass is also not suitable for an impromptu double boil, either.  The one where you just put a bowl over a simmering pot of water.  With the bottom under steam, the part contacting the pot getting full heat transfer from the metal, and the cooler top in air, that's the definition of heat stress.  Soda glass can't take it reliably.


----------



## alchemy_cake (Jul 5, 2017)

BrewerGeorge, thank you for your thorough explanation. In light of that information, I think I will wait and make sure I have safe plastic or steel to mix my lye in. I vividly remember the time I put a hot glass dish into a sink of water and had it shatter violently - I'm lucky it didn't hit my eyes, it was all over the kitchen.

As an aside, I'll be doing all of my mixing on my glass stovetop. I figure it should be able to handle the heat.


----------



## artemis (Jul 5, 2017)

For a small batch, why not dig through your reclycle bin and see what you have in there that is big enough for your lye? I use a 32 oz yogurt container for mine (all of my batches are small). This way, you can be safe and not have to wait.


----------



## alchemy_cake (Jul 5, 2017)

Artemis, that's a good idea. I'll see if any of my cheese containers will do. It'll just be a 1 pound batch, so the container probably doesn't need to be very big.


----------



## cmzaha (Jul 5, 2017)

I also use it once in awhile for a tiny test batch. I do not mix my lye solution in pyres but will use it for a small batch of soap batter


----------



## artemis (Jul 5, 2017)

alchemy_cake said:


> Artemis, that's a good idea. I'll see if any of my cheese containers will do. It'll just be a 1 pound batch, so the container probably doesn't need to be very big.



That's my usual batch size. The 32 oz is a nice size for that for the amount of lye and water you would use.


----------



## penelopejane (Jul 5, 2017)

The rubber base on your mixing bowls might be a bit problematic if you are a messy soaper. I don't think I would survive the batter? 

I don't like to use metal making soap because of DOS (even though SS should be safe) and because it's so dark in a metal pot that it's difficult to see what's happening and you can't see what's happening at the bottom at all.


----------



## Zany_in_CO (Jul 5, 2017)

alchemy_cake said:


> Pyrex does seem to be used a LOT by experienced soapers,


True. It's easier to see what's happening... especially when making transparent soap which is one of the first soaps I ever made. I melt my oils in the microwave in an 8-cup Pyrex.


toxikon said:


> My comment may get some grimaces, but I use my  Pyrex bowl for my oils and batter mixing. I make my lye solution in a  safe plastic jug, but I do pour my lye solution into my Pyrex bowl to  mix with my oils. I've been using the same Pyrex bowl for years without  issue.  ... It still looks brand new, I don't see any  etching.


^^^^^ Ditto


BrewerGeorge said:


> Fully  prepared for the flaming, I do exactly the same thing.  I know it's not  best practice and I don't recommend it for anyone else, but I feel safe  enough doing it.


^^^^^ Ditto.


artemis said:


> For a small batch,  why not dig through your reclycle bin and see what you have in there  that is big enough for your lye? I use a 32 oz yogurt container for mine  (all of my batches are small). This way, you can be safe and not have  to wait.


Good advice, Artemis. In the early days, I used 32 oz Dannon Yogurt containers.  I use a re-purposed plastic lye container with straight sides and a wide mouth to mix my lye solution... set in the sink, BTW.  Lye containers like the ones from WSP, Boyers, The Soap Dish, and a few others are perfect for re-use. I have several so I can make 3 batches of lye solution, stick them in the fridge to cool overnight, obviously well marked, and make 3 batches of GM soap, one after another, the next day. Works for me.  
HTH   :bunny:​


----------



## alchemy_cake (Jul 6, 2017)

Thank you all for your advice. After all that, I came down with a horrendous cold, so I have to wait anyway as I don't want to make any mistakes due to the fatigue. Signs point to feeling better tonight, so hopefully tomorrow I will be able to post pics of my first batch!


----------



## neonstudy (Jul 6, 2017)

I use Pyrex for everything! Lye, soap batter, etc! I do have one plastic bowl that I can use for lye. For soap batter, I like to heat mine in the microwave. Does anyone have any suggestions for what to use for that, so that you can see how everything is progressing? I also have used Pyrex for microwave hot process. Any suggestions there for replacements? I wonder if any plastic is see through and heat safe?


----------



## penelopejane (Jul 6, 2017)

deleted


----------



## penelopejane (Jul 6, 2017)

neonstudy said:


> I use Pyrex for everything! Lye, soap batter, etc! I do have one plastic bowl that I can use. Does anyone have any suggestions for what to use for that, so that you can see how everything is progressing? I also have used Pyrex for microwave hot process. Any suggestions there for replacements? I wonder if any plastic is see through and heat safe?



Any plastic container that has a 2 or  a 5  in the little triangle on the bottom is suitable.


----------



## BrewerGeorge (Jul 6, 2017)

neonstudy said:


> I use Pyrex for everything! Lye, soap batter, etc! I do have one plastic bowl that I can use for lye. For soap batter, I like to heat mine in the microwave. Does anyone have any suggestions for what to use for that, so that you can see how everything is progressing? I also have used Pyrex for microwave hot process. Any suggestions there for replacements? I wonder if any plastic is see through and heat safe?



If that's red pyrex, that's really quite dangerous.  I'm not one to tell people what they should and shouldn't do, but that is legitimately risky. No joke.

If you insist on clear, your best bet is to go to a laboratory web site and buy real borosilliate PYREX beakersm like this.  They're pretty spendy, though.


----------



## Zany_in_CO (Jul 7, 2017)

BrewerGeorge said:


> If you insist on clear, your best bet is to go to a laboratory web site and buy real borosilliate PYREX beakersm like this.  They're pretty spendy, though.


Lotion Crafter has a nice selection of borosillicate beakers as well. Unfortunately, because of the shape, the large ones are better suited to lotion making than soapmaking. I use the smaller sizes fairly often. Here's a link:

http://www.lotioncrafter.com/equipment-mixing-measuring/


----------



## alchemy_cake (Jul 7, 2017)

Looking at my plastic Tupperware tonight, I saw that most of it is marked 5. So, I guess if one were in a pinch...

Still feeling under the weather, but I assembled everything I'll be using. This is my first time trying to attach a picture, so I hope it works...

Yep, that's Pyrex - for mixing batter at cool temps only, unless I can find another plastic bucket in the meantime. The plastic bucket I do have (with the lye bottle in it) is marked 2, and the spoon is silicone.


----------



## fuzz-juzz (Jul 8, 2017)

That's the old Pyrex. It should be fine.
I've been soaping with mine for 5+ years. 
I melt oils in it (microwave) and add lye water, mix into batter and then separate. I even gelled CP liquid soap in it.
As long as it's not exposed to sudden temperature changes, it should be fine.
I'm mixing water and NaOH in cheap plastic jug (heat and chemical resistant).


----------



## MiHan (Jul 8, 2017)

The lye will slowly eat away the pyrex. It would take a long time before it shatters, but it's impossible to know when it will shatter. And cleaning up strongly basic material is just a pain.


----------



## BrewerGeorge (Jul 8, 2017)

That is NOT the old Pyrex.


----------



## penelopejane (Jul 8, 2017)

BrewerGeorge said:


> That is NOT the old Pyrex.



What are you doing responding while you are on holiday?
Can't keep that addiction at bay can you?  :mrgreen::mrgreen:


----------



## fuzz-juzz (Jul 9, 2017)

BrewerGeorge said:


> That is NOT the old Pyrex.



To me it was. Mine is almost 20 years old.
Most troubles with them come due to improper use.
I thought they changed when shape changed.


----------



## IrishLass (Jul 9, 2017)

fuzz-juzz said:


> To me it was. Mine is almost 20 years old.


 
1998 is when the formula was changed from borosilicate to soda lime glass, so it is very possible that yours could be made with the newer soda lime formula.



fuzz-juzz said:


> I thought they changed when shape changed.


 
From what I've been able to find online so far, it is as BrewerGeorge said- the lettering is a clue-, i.e., Pyrex measuring cups that spell the name in all lowercase lettering (i.e., pyrex) is the kind that's made with soda lime glass. The Pyrex measuring cup in the pic above has all lowercase lettering. The kind made from borosilicate should have all uppercase lettering (i.e., PYREX).




			
				fuzz-juzz said:
			
		

> Most troubles with them come due to improper use.


 
Although I don't dispute the above statement in the least, the troubles that arise when using them for making lye solutions or lye-based soap are due to the combination of high pH and heat. According to this tech data sheet on Pyrex borosilicate glass the only things that can cause appreciable corrosion of Pyrex borosilicate glass are these: hydrofluoric acid, hot concentrated phosphoric acid *and strong alkaline solutions *(emphasis mine). According to the tech sheet Pyrex borosilica glass is only _moderately_ alkali-resistant. 

Corrosion to glass comes in the form of chemical etching, which gradually weakens the glass more and more over time as it is continually used to mix such substances. I liken soaping in Pyrex to playing the game of Russian Roulette, where each batch of soap or lye solution represents a single pull of the gun's trigger- you just never know if your current batch is going to be the pull of the trigger that causes things to go kaboom. If you ask me, it's not worth the risk when certain plastics that are more highly alkali-resistant than Pyrex are in abundance. ​ 

IrishLass


----------



## dbloomingdale (Jul 9, 2017)

I use a plastic pitcher for my lye and a stainless steel pot to blend in everything.  Am I doing it wrong?


----------



## IrishLass (Jul 9, 2017)

dbloomingdale said:


> I use a plastic pitcher for my lye and a stainless steel pot to blend in everything. Am I doing it wrong?


 
I do the same thing. 


IrishLass


----------



## penelopejane (Jul 9, 2017)

IrishLass said:


> 1998 is when the formula was changed from borosilicate to soda lime glass, so it is very possible that yours could be made with the newer soda lime formula.
> 
> From what I've been able to find online so far, it is as BrewerGeorge said- the lettering is a clue-, i.e., Pyrex measuring cups that spell the name in all lowercase lettering (i.e., pyrex) is the kind that's made with soda lime glass. The Pyrex measuring cup in the pic above has all lowercase lettering. The kind made from borosilicate should have all uppercase lettering (i.e., PYREX).
> IrishLass



Just to complicate things we have lots of Pyrex in the kitchen as DH loves glass.  It is all relatively new and has red uppercase lettering (PYREX). I am guessing it is the new formula.  I don't use it for soaping. I use plastic with a 2 or 5 in the triangle on the bottom. 

I am in Australia so it might be different for you.


----------



## fuzz-juzz (Jul 10, 2017)

Spelling on my pyrex is lower case. So I guess it is newer glass then. It was purchased in early 2000s, can't remember the year, maybe 2001-2002.
I understand everything and that there is a certain risk but, there's risk with everything unfortunately.  
But now you scared me enough and I think I'll invest into something else. I literally make maybe 2 batches a month but I don't think it's worth the risk. I'm clumsy enough anyway...
I have quite a few of pyrex bowls in the kitchen which I use for everything. They are all around 5-10 years old and they go through so much abuse. None of them ever caused any issues.
I still don't think all of the pyrex is bad. There's millions of their products all around the world. Whatever we hear about explosions etc are isolated cases, there's internet, word goes around and there you go, people get scared. 
But better be safe than sorry...


----------



## artemis (Jul 10, 2017)

fuzz-juzz said:


> But now you scared me enough and I think I'll invest into something else. I literally make maybe 2 batches a month but I don't think it's worth the risk. I'm clumsy enough anyway...
> 
> Whatever we hear about explosions etc are isolated cases, there's internet, word goes around and there you go, people get scared.
> But better be safe than sorry...



When there are soap safe mixing bowls available at the dollar store, there is no reason to risk it.

And, this isn't random internet hysteria. The lye will, in fact, etch the glass.


----------



## The Efficacious Gentleman (Jul 10, 2017)

^^^^ this is where I sit. 

If the question is "will I certainly have an issue using glass?" The answer is no. It might well happen that you get lucky or replace the glass before anything happens. 

If the question is "am I far more likely to have an issue with glass rather than appropriate plastic or good stainless steel?" The answer is most certainly "YES!" 

As appropriate plastic is not very expensive and good stainless is good value for money, there really is no reason to use glass unless a few dollars/pounds/euros is a deal breaker. And in the grand scheme of soaping costs, it isn't!


----------



## penelopejane (Jul 10, 2017)

fuzz-juzz said:


> But now you scared me enough and I think I'll invest into something else. I literally make maybe 2 batches a month.



Fuzz-juzz 
I use similar to this for 1kg oils. (1.2kg at a push) I like the handle! Woolies has the best everyday prices but they are often on special. Just make sure it has a 2 or 5 in the triangle on the base. 

http://www.decor.com.au/product/tellfresh-jug-2-0-l/


----------



## Helenz (Jul 10, 2017)

Ive been using my two pyrex jugs for the last 2-3yrs without any problems. Admittedly the soaping process is faster now that I know what Im doing and I make sure I clean up well. The jugs dont show any deterioration so far. cheers Helenz


----------



## Zany_in_CO (Jul 11, 2017)

Yeah, me too, Helenz, and for much longer than that. I can't help but wonder if all this hype about glass being dangerous vs plastic being safe is "speaking from personal experience" or based on some urban legend from long ago that's just been passed down from generation to generation. 

PS: My apologies to all who are offended by this difference of opinion. No worries. I'm sure this post will be deleted _tout suite. _


----------



## The Efficacious Gentleman (Jul 11, 2017)

Zany_in_CO said:


> Yeah, me too, Helenz, and for much longer than that. I can't help but wonder if all this hype about glass being dangerous vs plastic being safe is "speaking from personal experience" or based on some urban legend from long ago that's just been passed down from generation to generation.
> 
> PS: My apologies to all who are offended by this difference of opinion. No worries. I'm sure this post will be deleted _tout suite. _





I don't think that it will be, but your reasoning is still very flawed. 

I have once needed my seatbelt in my car. Once, in 16 years of driving. Many people have never needed it. Does that mean that they shouldn't wear it? Other people have been hurt or killed because of not wearing one, but that's not personal experience, right?

I have seen the state of a glass bottle which stored a weak lye solution for food use for a few months - there was a cloud of dissolved glass at the bottom of the bottle and the glass was visibly different from the glass above the solution. 

Lye does etch most glass over time. 

I hope that you never have an issue, I really do. But that does not make it responsible for you to suggest that there might never be an issue for other people based on your personal experience. That is just irresponsible and exceedingly foolish of you. It is not your opinion which offends me, it's the fact that others could well suffer serious issues because of how you present your opinion. Which is all it is - whether or not most types of glass are damaged over time by exposure to soaping level lye solutions is not a matter of opinion, is it? It's a provable point of fact.


----------



## IrishLass (Jul 11, 2017)

Zany_in_CO said:


> Yeah, me too, Helenz, and for much longer than that. I can't help but wonder if all this hype about glass being dangerous vs plastic being safe is "speaking from personal experience" or based on some urban legend from long ago that's just been passed down from generation to generation.
> 
> PS: My apologies to all who are offended by this difference of opinion. No worries. I'm sure this post will be deleted _tout suite. _


 
Unfortunately, no- it's not an 'urban legend' from long ago. One of my fellow (former) modmins had her pyrex all of a sudden shatter on her a few minutes after mixing her lye solution in it. Thankfully, it was sitting in the sink (cooling off) when it happened and she did not end up with glass and lye everywhere on her floor. I know of other soapers who have reported the same thing happening to them as well. Lye will chemically react with any type of glass, be it tempered or not. It reacts with the silica in glass, gradually dissolving it over time. The corrosion can happen rather quickly, too. Here is a demonstration of how quickly glass can dissolve when placed in molten NaOH: 

[ame]https://www.youtube.com/watch?v=nmktRTHL1NA[/ame]

Granted, we do not make soap using molten NaOH and will most likely never experience anything so dramatic or instantaneous, but the corrosion/etching/dissolving/weakening still goes on nevertheless, albeit at a much slower rate. 

Here is an excellent article that describes how glass corrodes: 

http://corrosion-doctors.org/Household/Glass.htm


IrishLass


----------



## Kittish (Jul 11, 2017)

I've got three brand new pyrex measuring cups in my kitchen that were originally bought for making soap. Only one of them is still tagged and has ever actually been used for soaping, and it's basically just to catch spatulas and whisks so they don't drip all over everything. I'm clutzy enough as it is, I don't need the added excitement of glass spontaneously shattering. 

My lye gets mixed in a stainless steel pitcher, and my soaping is done in stainless steel bowls unless it's a big batch, then I'll bring out the crock pot. I've also got assorted plastic vessels (all with either 2 or 5) for when I want to split a batch up.


----------



## toxikon (Jul 11, 2017)

I think most can agree that storing or even mixing your lye solution in glass is a bad idea.

But I, and I think a few other repliers, said that we just melt our oils in a glass vessel then add our lye solution to create the batter. I wonder how dangerous that is, since I assume the walls of the glass are covered in a thin layer of oil for the whole duration, and the lye is quickly mixed and diluted and begins saponification. Assuming you wash the bowl immediately afterwards, the risk seems quite low.

Eliminating the chance of risk is a valid point, but if we used that same logic in every aspect of our lives, no one would ever drive a car again... :mrgreen:

But with all that said, I will be on the lookout for some microwave safe bowls to switch over to!


----------



## shunt2011 (Jul 11, 2017)

toxikon said:


> I think most can agree that storing or even mixing your lye solution in glass is a bad idea.
> 
> But I, and I think a few other repliers, said that we just melt our oils in a glass vessel then add our lye solution to create the batter. I wonder how dangerous that is, since I assume the walls of the glass are covered in a thin layer of oil for the whole duration, and the lye is quickly mixed and diluted and begins saponification. Assuming you wash the bowl immediately afterwards, the risk seems quite low.
> 
> ...


 
I still don't think I would risk it on a regular basis.   I was doing lip balm in a pyrex measuring cup and had it sitting on a towel in slight simmering water and the bottom popped and separated/broke off.  Don't think I'll use lye with one.


----------



## kchaystack (Jul 11, 2017)

No, there is no 'thin layer of oil' protecting the glass from the lye.  The glass is still exposed to the high pH environment, is still exposed to NaOH.  This is as much a misconception as adding SF at trace protects it from the lye in CP soap.

Really, go buy a couple of paint mixing buckets from your closest hardware store.  the quart sizes are perfect for 500g batches, the 2.5 quart are perfect for up to 1100g batches.  they are cheap, and you can buy lids that fit them.  you could have several for under $10 US


----------



## toxikon (Jul 11, 2017)

kchaystack said:


> No, there is no 'thin layer of oil' protecting the glass from the lye.  The glass is still exposed to the high pH environment, is still exposed to NaOH.  This is as much a misconception as adding SF at trace protects it from the lye in CP soap.
> 
> Really, go buy a couple of paint mixing buckets from your closest hardware store.  the quart sizes are perfect for 500g batches, the 2.5 quart are perfect for up to 1100g batches.  they are cheap, and you can buy lids that fit them.  you could have several for under $10 US



Ideally, I'd like to find a microwave safe container with a spout that could fit 2-3lbs of batter in them. I'll be on the hunt.

Are there any studies out there that explicitly say that oil residue disappears from the glass when you add your lye solution? I'm just curious. Maybe DeAnna will chime in!

I've always heard that it's important to slide your spatula along the sides of your bowl, instead of just SBing, because oil residue can remain and it's important to incorporate it all.


----------



## kchaystack (Jul 11, 2017)

toxikon said:


> Ideally, I'd like to find a microwave safe container with a spout that could fit 2-3lbs of batter in them. I'll be on the hunt.
> 
> Are there any studies out there that explicitly say that oil residue disappears from the glass when you add your lye solution? I'm just curious. Maybe DeAnna will chime in!
> 
> I've always heard that it's important to slide your spatula along the sides of your bowl, instead of just SBing, because oil residue can remain and it's important to incorporate it all.



the 2.5 quart containers are microwave safe and will hold 3 lbs.  they are flexible enough that you can form a spout by squeezing the sides.

It important to make sure your batter is evenly mixed - but it isn't because of oil residue - its just to make sure all of your oil is mixed in.  And scraping the sides again exposes your glass to unreacted lye - because we KNOW that saponification has not finished in CP  for several hours.

Hey, if people are dead set on doing dangerous things, I won't stop them.  I also won't feel bad when the glass shatters - or it slips and falls on the ground and breaks so they have soap batter covered shards of glass all over.


----------



## SgtSluggo (Jul 11, 2017)

From a chemistry point of view - In the lab we have all Borosilicate glass (Lab-Grade pyrex or Kimex). Lab policy is that glass may be use for working with diluted alkaline solutions or with the dilution process when resulting in a greater than 50% dilution of the alkali.  Otherwise we are to use HDPE containers. I imagine that you could soap with the cheaper glass for years and years and never have a problem.  However, I think this is a lot like some of the other safety discussions here, in that it probably isn't worth the risk as glass probably doesn't have any real benefits other than availability and familiarity.  

FYI - The paint mixing buckets (which come in various sizes) available at home improvement stores like Lowe's and Home Depot are usually HDPE (#2) or Polypropylene (#5) plastic.  That is what I have been using for both the lye solutions and mixing.  I think I only paid about a dollar or two for each so I have spares and don't have to worry about not having enough containers while working.


----------



## toxikon (Jul 11, 2017)

kchaystack said:


> the 2.5 quart containers are microwave safe and will hold 3 lbs.  they are flexible enough that you can form a spout by squeezing the sides.
> 
> It important to make sure your batter is evenly mixed - but it isn't because of oil residue - its just to make sure all of your oil is mixed in.  And scraping the sides again exposes your glass to unreacted lye - because we KNOW that saponification has not finished in CP  for several hours.
> 
> Hey, if people are dead set on doing dangerous things, I won't stop them.  I also won't feel bad when the glass shatters - or it slips and falls on the ground and breaks so they have soap batter covered shards of glass all over.



I'm not trying to argue or say that we should take risks in soapmaking by any means... I'm just curious about the science behind soap batter + glass, that's all. It's an interesting topic.

It is kinda funny that Soap Queen uses glass for all their tutorials if it's so unsafe, considering that's where most new soapers get their info from. There must be tons of people out there using glass and you really don't hear many horror stories and many people seem to be unaware of the risks. 

I trust the judgement of the experienced folks here over SQ any day, so I will make the switch. I just wonder what the actual "odds" are. Is there a 1:50 chance of glass etching or 1:100,000? Inquiring minds and all that...


----------



## kchaystack (Jul 11, 2017)

toxikon said:


> It is kinda funny that Soap Queen uses glass for all their tutorials if it's so unsafe, considering that's where most new soapers get their info from. There must be tons of people out there using glass and you really don't hear many horror stories and many people seem to be unaware of the risks.



She also talks about soap 'nourishing' your skin, and being 'moisturizing'.  

There is another YT soaper who master batches lye in old pasta sauce and pickle jars.  And I KNOW those will explode just by sudden heat changes - because it has happened to me more than once.


----------



## DeeAnna (Jul 11, 2017)

Whether or not a pyrex container will "explode" is a moot issue for me. What is of more concern to me whether I'm willing to risk cleaning up any spill of lye or soap batter mixed with glass shards ... or if just the spill itself is sufficiently bad enough.

It only takes a small mistake when making soap, and ~~oops!~~ there's a container of stuff on the floor or counter. If the container is plastic or metal, there won't be shards. If glass, there are likely to be shards and there will be a much higher risk of injury. 

NaOH on normal skin is bad enough ... I am not going to put myself or anyone else at risk for NaOH in a cut or scrape due to broken glass, however small the injury might be. This is a no-brainer safety issue for me, so I don't quite get why there's any debate about this matter.

***

As far as whether there is a film of fat "protecting" the glass ... nope, this is a myth.

What might be the root of this myth is the engineering idea of a specific type of flowing liquid (or gas) passing slowly through a pipe. In this specific situation of "laminar flow", there will be a non-moving layer of fluid right against the pipe. 

Problem is, once the laminar flow condition is disturbed by any turbulence (stick blending, anyone?) or any other kind of action (scraping with a spatula, perhaps?), then there is no laminar flow and no "protective" film against the pipe. 

So you ask -- then why is a soap pot so greasy? I agree it's greasy from the fats ... but it's also covered with residues of active lye ... and residues of the other ingredients in your soap batch. Just because the fat is more visible and harder to wash off than the other stuff doesn't mean the other stuff isn't there. 

Think about sauteing onions or chops in a fry pan. The film of olive oil or other fat on the pan doesn't eliminate food residues from sticking to the pan, which tells me that the fat doesn't form a perfectly protective film on the metal of the pan. If it did, there would be no reason for non-stick coatings on saute pans. Same idea with a soap pot.


----------



## BrewerGeorge (Jul 11, 2017)

To me, decisions are a combination of what is possible and the consequences of it happens. I wouldn't point a gun that I was *sure* was unloaded at my head and pull the trigger because the consequence is unacceptable no matter how minute the chance. Conversely, if the consequence is low - say a water gun -  I will accept a higher probability of mishap. 

IMO, hot lye solution in glass has consequences that are unacceptable at any likely hood of occurrence, compounded by actually being the situation most likely to fail. Perfect storm. 

The big pyrex batter  bowl, though is both less dangerous if something happens and less likely to happen. We've all spilled batter and lived to tell of it, right? That's the worst that happens if a bowl falls - maybe just a larger scale.  As I said from the beginning, though, it's still not best practice but I'm comfortable with the risk to potential balance for now.


----------



## penelopejane (Jul 11, 2017)

When I was 11 I poured hot oil into a Pyrex jug and it shattered over my foot. I was home alone but luckily knew enough to put my foot in a bowl of cold water until my parents came home and took me to hospital.  I'll never forget it. 

I subsequently learnt that Pyrex (even the good stuff) isn't designed for direct heat or sudden temp changes. I hope someone learns from my experience.


----------



## mx5inpenn (Jul 11, 2017)

toxikon said:


> Ideally, I'd like to find a microwave safe container with a spout that could fit 2-3lbs of batter in them. I'll be on the hunt.
> 
> Are there any studies out there that explicitly say that oil residue disappears from the glass when you add your lye solution? I'm just curious. Maybe DeAnna will chime in!
> 
> I've always heard that it's important to slide your spatula along the sides of your bowl, instead of just SBing, because oil residue can remain and it's important to incorporate it all.



I've picked up a couple large mixing bowls with pour spouts, #5 recycling code, at dollar tree that hold 3+ pound batches.


----------



## fuzz-juzz (Jul 11, 2017)

How bad are those jugs that came out about 5 years ago.
I still have one but I rarely use it.
You can't pour cup of anything without spilling half, doesn't matter how much you try.
They're certainly not for soaping unless you want half of your soap batter on the bench.
I think they've fixed the design again. I can't see those terrible jugs in shops anymore. I love pyrex but those were such a fail haha.

I mainly use mine for marinating stuff, as salad bowls, quick microwaving, cake batter etc.
I have few that I bake in but 15 years on and I've never had an issue.


----------



## Arthur Dent (Jul 11, 2017)

Its the song that never ends...


----------



## Zany_in_CO (Jul 12, 2017)

arthur dent said:


> its the song that never ends...



?  ?  ?​


----------



## artemis (Jul 12, 2017)

Arthur Dent said:


> Its the song that never ends...



 I was thinking the same thing.


----------



## dibbles (Jul 12, 2017)

The Song That Never Ends is a children's song
https://en.wikipedia.org/wiki/The_Song_That_Never_Ends

It is one of those songs that sticks in your head and won't stop, not unlike "It's a Small World"


----------



## toxikon (Jul 12, 2017)

To be fair, there are a lot of "never-ending songs" around this forum... doesn't mean we should discount an interesting discussion on the effects of lye on glass.


----------



## dibbles (Jul 12, 2017)

toxikon said:


> To be fair, there are a lot of "never-ending songs" around this forum... doesn't mean we shouldn't discount an interesting discussion on the effects of lye on glass.



I agree.


----------



## IrishLass (Jul 12, 2017)

dibbles said:


> The Song That Never Ends is a children's song
> https://en.wikipedia.org/wiki/The_Song_That_Never_Ends


 
Ack!- the Lambchops/Shari Lewis song! That was one of my son's favorite shows to watch when he was real little. Just when I thought I had finally gotten that song out of my head forever! Thank you _ever_ _so much_ for the reminder Dibbles. :twisted: 




> To be fair, there are a lot of "never-ending songs" around this forum... doesn't mean we shouldn't discount an interesting discussion on the effects of lye on glass.


 
I agree as well. Especially since there are always more and more newcomers to the craft (and to the forum) whose only prior knowledge of soapmaking may have come from reading a few blogs or watching a few videos online that unbeknownst to them contained very questionable practices or faulty info. I view threads like these as more of a positive than a negative because they help get the word out so that newcomers can get started off on the right foot.


IrishLass


----------



## Traumabrew (Jul 12, 2017)

I use pyrex measuring cups and/or the 6 quart glass mixing bowl from a kitchenaid stand mixer to mix oils and lye solution. Stainless steel is safe for lye solutions however aluminum isnt. Most commercial operations use stainless steel as it isnt reactive with lye. I use lab quality borosilicate beakers (the  500 ml, 1000ml and 2000 ml are quite nice and cheap) for making my lye solution. I have concerns over the lye leeching compounds form the plastic containers. I do use plastic long spout containers to portion out my soap batter and mix colors in, but the length of time they are in these containers is minimal. Lye solution will sit in its container for an extended period of time as it cools.


----------



## alchemy_cake (Jul 13, 2017)

IrishLass;654454
I agree as well. Especially since there are always more and more newcomers to the craft (and to the forum) whose only prior knowledge of soapmaking may have come from reading a few blogs or watching a few videos online that unbeknownst to them contained very questionable practices or faulty info. I view threads like these as more of a positive than a negative because they help get the word out so that newcomers can get started off on the right foot.
 
 
IrishLass :)[/QUOTE said:
			
		

> And I really appreciate everyone's input! I had no idea this would end up being such a subject of debate. I've enjoyed following the conversation, though; I feel that I've learned a lot.


----------



## shunt2011 (Jul 13, 2017)

IrishLass said:


> Ack!- the Lambchops/Shari Lewis song! That was one of my son's favorite shows to watch when he was real little. Just when I thought I had finally gotten that song out of my head forever! Thank you _ever_ _so much_ for the reminder Dibbles. :twisted:
> 
> 
> 
> ...


 

And this is where my name came from..... Ha Ha!


----------



## WhiteRiverSoap (Jul 17, 2017)

Pyrex is quite safe.  Over time, caustic can etch the glass, but this would take literally hundreds of batches before you would even notice and you would likely throw out the pyrex cup before it caused any issues as the glass would become a bit frosted before any problems.


----------



## The Efficacious Gentleman (Jul 18, 2017)

WhiteRiverSoap said:


> Pyrex is quite safe.  Over time, caustic can etch the glass, but this would take literally hundreds of batches before you would even notice and you would likely throw out the pyrex cup before it caused any issues as the glass would become a bit frosted before any problems.





Did you read any of the previous posts before posting this?

That aside, is Pyrex quite safe or very safe? At what sign of frosting should I stop using it? Are you assuring me completely that I will have no other issues with my Pyrex (of any quality) with my soaping? Can you provide your contact details for me to claim on your insurance when something happens to my Pyrex which doesn't fit with your guidelines for frosting etc?


----------



## navigator9 (Jul 18, 2017)

WhiteRiverSoap said:


> Pyrex is quite safe.  Over time, caustic can etch the glass, but this would take literally hundreds of batches before you would even notice and you would likely throw out the pyrex cup before it caused any issues as the glass would become a bit frosted before any problems.



Back when I first started making soap, around 10 years ago, I had seen it recommended somewhere to use Pyrex for mixing lye, so I did. Soon after, definitely not "hundreds of batches" later, I noticed that the glass looked cloudy. Luckily, I read that this etching is caused by the lye, and eventually the glass will begin to release micro shards of glass. I don't know that there is any way to predict when this will happen, but it wasn't something I was willing to risk, so I threw the Pyrex out. 



penelopejane said:


> I don't like to use metal making soap because of DOS (even though SS should be safe) and because it's so dark in a metal pot that it's difficult to see what's happening and you can't see what's happening at the bottom at all.



pj, ever since getting rid of my Pyrex cup, I've used a SS saucepan for my lye solution. SS isn't dark, so I can easily see to the bottom, and I like that the metal makes it easy for me to gauge the temperature by feeling the outside of the pot. I've used the same saucepan for years, with no problems, and I've continued to also use it for cooking with no problems. 

I know there are plastics that can also be used for lye, but I already had the saucepan, as well as the SS stockpot that I use for making my larger batches of soap. SS is non porous, so there's no problem using SS for both soaping and cooking, provided of course, that you wash it well. I think most people have SS pots of various sizes already, so I'm surprised that more don't use them. As for DOS, I've had a batch or two early on, but not in years, and as I've said, I use the SS all the time.


----------



## penelopejane (Jul 18, 2017)

navigator9 said:


> pj, ever since getting rid of my Pyrex cup, I've used a SS saucepan for my lye solution. SS isn't dark, so I can easily see to the bottom, and I like that the metal makes it easy for me to gauge the temperature by feeling the outside of the pot.



You are right of course about SS. I like to be able to see the batter mixing so plastic is perfect for me.


----------



## penelopejane (Jul 19, 2017)

Helenz said:


> Ive been using my two pyrex jugs for the last 2-3yrs without any problems. Admittedly the soaping process is faster now that I know what Im doing and I make sure I clean up well. The jugs dont show any deterioration so far. cheers Helenz



You are in New Zealand. Pyrex made by Corning sold in NZ and Australia is different from that made in the USA. If it is made by Corning in Australia it will be the safer than that made in the US. The capital lettering on the container is one indication but there is also smaller writing saying where it is made. Google Pyrex for more info.  It was a "good" Pyrex container that exploded on me. I still don't trust it for hot liquids. 

It would be good if you added your location to your name to avoid confusion.


----------



## psfred (Jul 22, 2017)

You need to be aware that "pyrex" means two different things -- it's a registered trademark for borosilicate glass by Corning, and in the old days, before the word became generic (and everything wasn't made in China) the "Pyrex" marking meant borosilicate glass.  While it will eventually frost, it's OK to use a few times.

Sadly, someone got all bent out of shape about the miniscule amount of boron that CAN (note I said CAN) leach out of borosilicate glass, and it was banned from food use.  That means "Pyrex" became a trade name for glass cookware, and it's quite dangerous.  Lots of reports of exploding "Pyrex" pans, etc because tempered glass is NOT borosilicate glass, it's silica based glass and quite fragile in comparison.  It will indeed shatter unexpectedly under thermal stress, and does not have to be etched by lye first, although that will make failure more likely rather than less.

So, bottom line, unless you KNOW your "Pyrex" container was made before about 1986, assume it's plain tempered glass and do NOT mix lye in it, it's subject to thermal stress cracking, a bad thing.  Older Pyrex is probably quite safe -- I use it in the chemistry lab all the time for making strong lye solutions and have never had a beaker break, even a badly etched one.  Lots of plain glass failures though.

Plastic or stainless is safer, and you really don't want hot lye running all over your countertop....

Peter


----------

