# Help with calc issues, please



## Nehlena (Feb 18, 2015)

LunaSkye said:


> 4. Super fat is where you enter how much of a lye discount you want for your soap.
> ..........
> Lye converts oils indiscriminately into soap, so the SF is often referred to the lye discount.



Why do I have a problem on understanding this? 

1) I have understood that in CP method, lye does not discriminate and saponifies the added even at trace oils, right?

2) If someone *only* uses lets say the lye:water ratio of #3 (not shown in the quote), and always uses a constant NaOH:H2O ratio eg. 1:2, on all of their recipes (is this wrong?)

here comes the question, if the ratio is always kept constant at any recipe, how then SF can be referred to as lye discount? Unless, this applies if I vary the ratio or I am totally confused...doh!:crazy::crazy:


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## The Efficacious Gentleman (Feb 19, 2015)

*How To Use Soap Calc Tutorial*

In reverse order -

You use a lye amount correct for your recipe. That might be 100g or 134g. But you use the lye that the calc says to use. How much water you use is pretty much up to you - the only way it is wrong is if you use less water than lye and if you use less or more water than your plans need. So if you want a slow trace, use more water. A faster set up time, less water. You need to find this balance. 

The amount if lye is always based on the recipe - that is the important part. You change your water amount, not the lye amount. 

The lye discount comes from this - if my recipe needs 100g of lye to be totally saponified, no superfat and not lye heavy, then when I use 95g lye, 5% of my oils won't have any lye so they won't saponify. As above, the amount of water does not matter here, the amount of lye is important. 

As for the cp/trace question, I am afraid that adding oils at trace does not make them a superfat. Trace is the start of saponification, not the end, so it makes no difference at all. You can think that it does because of what some books say, but it just really is not true.


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## DeeAnna (Feb 19, 2015)

Maybe I can try to explain. 

There are three important things in soap:

Fats
Lye
Water

The first two are the most important.

Once you decide on the kind of fats and the weight of each fat in the recipe, then you calculate the amount of lye. The "theoretical amount of lye" is the exact amount of lye needed to convert all of the fat into soap -- no more lye than that and no less.

Theoretical lye needed for Fat 1 = (Weight of Fat 1) X (Saponification value for Fat 1)
Repeat for each fat in your recipe. 

Add all the weights of lye together for the theoretical amount of lye needed for the entire recipe.
Theoretical lye needed for recipe = (Lye needed for Fat 1) + (Lye needed for Fat 2) + (Lye needed for Fat 3) + (and so on)

If you want no extra lye and no extra fat in the recipe, then this theoretical weight of lye is the amount needed to make your soap. This amount of lye is what is normally called a "zero lye discount".

If you want a little extra fat left over in your soap, then you will want to use slightly less lye than this amount. The amount of lye removed is called the "lye discount". 

If your lye discount is 5% for example, then the actual amount of lye you would use to make your soap is this:
Total lye needed for recipe at 5% lye discount = (Lye needed for zero lye discount) X (1 - 5/100)

When a soap is made with a lye discount, the extra fat remaining in the soap after it is saponified is called "superfat". 

There is a second way to add superfat when one makes hot process soap, and that is to add fat directly to the soap after it is saponified. But that's another story. 

***

Getting back to the matter at hand -- It's important to see that I have not said ANYTHING about the water needed for the soap recipe. The lye, as The Gent explained, is calculated based ONLY on the fats you choose for the recipe and whether you want some of those fats left unsaponified (in other words, whether your lye discount is something other than zero). 

***

We now know what weights of fats and lye are needed for a particular recipe, and these weights will not change for this specific recipe.

Let's move onto the water. The amount of water in a soap recipe can vary depending on what you want to do with the soap. If you use the same weights of fats and lye -- but use a different amount of water for each batch -- you will still end up with good soap and each batch will have the same amount of superfat.

Many soapers use what is called "full water" for their lye solution concentration. "Full water" is about a 28% lye solution concentration. This means for every 100 grams of lye solution, 28 grams of that is lye and the rest is water.  This is about the lowest concentration of lye solution you would want to use to make solid (bar) soap.

The other extreme is to dissolve lye in an equal weight of water. This makes a 50% lye solution concentration. In this case, for every 100 grams of lye solution, 50 grams is lye and 50 grams is water. The ratio of water to lye is 1 part water to 1 part lye.

You can use any lye solution concentration in between 28% and 50%. For example, some soapers use a 33% lye solution concentration. This means for every 100 grams of lye solution, 33 grams is lye and 67 grams is water. The ratio of water to lye is 2 parts water to 1 part lye.

***
Hope this helps.


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## IrishLass (Feb 19, 2015)

Nehlena said:


> Why do I have a problem on understanding this?
> 
> 1) I have understood that in CP method, lye does not discriminate and saponifies the added even at trace oils, right?


 
True. 




Nehlena said:


> 2) If someone *only* uses lets say the lye:water ratio of #3 (not shown in the quote), and always uses a constant NaOH:H2O ratio eg. 1:2, on all of their recipes (is this wrong?)
> 
> here comes the question, if the ratio is always kept constant at any recipe, how then SF can be referred to as lye discount? Unless, this applies if I vary the ratio or I am totally confused...doh!:crazy::crazy:


 

I know how confusing this all must seem, but the lye to water ratio actually has nothing to do superfat or lye discount %. No matter what super fat % you choose to use, and no matter what lye-to-water ratio you choose to use, changing either one of them will not have an effect on the other.

"Lye Concentration" in box #3 on SoapCalc is based only on one's lye amount as it relates to how much water will be used in one's recipe, i.e., how concentrated do you want your lye solution to be.... more concentrated so that the soap will set up quicker, or more dilute so that the soap will set up at a slower pace, which will give you more time to play with your colors and swirls? 

On the other hand.......

"Super Fat" in box #4 on SoapCalc is solely based on one's lye amount as it relates to the oils/fats in one's recipe, i.e., how much of a safety-net of unsaponified fat do you want to have leftover in your finished soap? 

Re: 'Super Fat' vs. 'Lye Dicount': Basically, as far as a soap's outcome in concerned (i.e., having an excess of fat), the terms are interchangeable with each other, but there is a very slight technical difference in how the outcome is achieved.....

When one 'super-fat's' their recipe, they add a certain percentage of oil/fat of their own choice directly to the soaping pot either at trace in CP (which is futile, btw), or after the cook in HP. 

When one uses a 'lye discount', they decrease their lye amount by a certain percentage of their own choice in their 'up-front' calculations and then add all their oils/fats together before adding the lye solution to them.

In the end, both of the different soap formulas will end up with an excess of fat in the finished bars, but it's all a matter of how it was achieved.

On SoapCalc, they have only the 'Super Fat' box, but it can be used for either approach.


IrishLass 


Edited to add- DeeAnna beat me to it again! I was still writing while she was posting. lol


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## Nehlena (Feb 20, 2015)

Thank you, thank you ALL for your replies and time given to me...

Lets see what I have understood (?)...

In my case, the following recipe that I want to make, it consists of 95% extra virgin OO and 5% babassu oil. I have made an extra virgin OO dandelion infusion and a strong tea again with dandelion that will be the water part... I will soap at 48C (120F), no EO,s...

I will also dissolve 1 tsp of sugar in my tea prior adding the lye to increase the bubbles...

Now... since I have read that a heavy amount of extra virgin OO traces really slow, I decided to follow the road that deals with water:lye ratio although I could also follow the lye discount method by plugging in 50% discount.

The end result is the same, only the road attaining this is different... right? 

And I choose to use so concentrated lye solution in order with a whisk and a little stick blend to trace with an easier effort...

Safety measures always...


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## The Efficacious Gentleman (Feb 20, 2015)

No, I am afraid not.

The lye discount is about how much lye is needed to saponify the oils.  It has nothing to do with how much liqiud you use, simply how much of the powder/flakes/beads of NaOH that you need.

You then add this to a liquid to make "lye solution" and this is where the water ratio comes in.  An example, but a made up one as I can't get soapcalc on this machine...............

So, I have a 100% OO recipe.  I want to use 500g oils.  

If I leave the "lye discount" at 5%, that means that the amount of lye given will allow 5% of the oils to remain free.  Let's say the lye amount is 85g.

Next comes the water.  The lowest ratio would be 1:1 as lye needs as much liquid as itself to dissolve.  So that is 85g of water for my 85g of lye.  But I would NEVER soap with that as it would be a pain to work with and trace quicker than the NSA.  So I go for 1:2 ratio, which means twice as much water as lye, which is then 170g water and 85g lye.

Notice that the lye amount hasn't changed, even though the water amount has?

The lye discount and water discount are two very VERY different things.  Do not confuse them.


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## Susie (Feb 20, 2015)

I would not suggest you make smaller than a 500g batch.  As a matter of fact, I would strongly suggest you make no smaller than a 1kg batch.  Small errors(mis-weighs) make a HUGE difference in smaller batches.


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## DeeAnna (Feb 20, 2015)

"...I decided to follow the road that deals with water:lye ratio although I could also follow the lye discount method by plugging in 50% discount. The end result is the same, only the road attaining this is different... right? ..."

Oh, my, no, this is not right! All of us are trying to explain to you that the lye discount is NOT the same as the water:lye ratio.

Until you understand the difference, you are going to make a horrible mess -- your soap will be soft, greasy and unusable; or it will have too much lye and injure your skin. 

Do not make soap until you get this figured out, please!


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## Susie (Feb 20, 2015)

Let me see if I can help here.  

Lye discount(often mis-named as superfat) is the amount of oil left after the lye changes the rest of it to soap.  This somewhat effects how "conditioning" soap feels.

Lye/water ratio is how much lye is to how much water.  THIS affects trace time.  

However, you are a new soaper(correct me if I am wrong.)  You are also attempting a soap that is going to take MONTHS to be able to test.  This is not a wise choice.  You are going to want to try that soap way before it is anywhere near ready.  Then you are going to want to make more without knowing whether this is any good or not.  Do you see the problem?

You are also trying to do WAY too many things with this soap if you are, indeed, new.  Again, please correct me if I am wrong.  You need to not try all the infusions and tea- none of the goodness of the dandelion is going to survive the process.  And the color is not going to be anything like you expect.  I would also not add sugar to soap if you are this new.  Soap volcano is not a happy experience.


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## DeeAnna (Feb 20, 2015)

If I make a cake and the recipe calls for 2 eggs, can I add just 1 egg to the cake batter and make a good cake? No. The chemical reaction between the eggs and the flour will not work properly if there is not enough egg. The cake will be hard and dry.

If I make a cake and the recipe calls for 2 MEDIUM sized eggs, can I add two LARGE eggs and make a good cake? Probably yes.

Lye for soap is like eggs for a cake. I have to use enough lye with my fats to make good soap. A lot less lye or a lot more lye will not make good soap. 

I can add a tiny bit less lye and make good soap, but the amount of lye has to be fairly close to the right amount for the chemical reaction to happen properly. The "tiny bit less" is created by the "lye discount". 

*** 

If I make a cake and the recipe calls for 1/2 cup of milk to be mixed with the 2 eggs, can I mix a more milk into the eggs and make a good cake? Probably yes. The cake might be moister with more milk, but it should be fine.

The amount of water in soap is like the amount of milk in a cake. I can make my soap with a little more water or a little less water and I can still make good soap. My soap might be a little drier or a little more moist, but it should be fine. The amount of water in my soap is set by the "water:lye ratio".

***

Milk in cake and water in soap are one thing. They are not the same as the number of eggs in cake and the amount of lye in soap. I hope you can see the difference.


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## Seawolfe (Feb 20, 2015)

Yeah simplify simplify for your first batches. You really need to understand the basics first! And make your first batches at least more than 700 grams - 900 would be better, unless you have a scale that does micrograms and you have chemistry experience 

Just remember that a descriptor that has to do with "lye" like "lye discount" or "lye excess" has to do with how much lye is meeting your oils and fats - your so-called superfat - with a lye discount you're just adding a little bit less lye to allow the soap to have a bit of oil excess. So on soap calc a 5% superfat is really a 5% lye discount and you use only 95% of the lye needed to fully saponify your oils and fats.

Any word to do with "water" such as "full water" or "water discount" are only to do with the amount of water or liquid you add to the lye. Honestly just use the soap calc default of "water as % of oils = 38"  and you'll be fine as you start.


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## Nehlena (Feb 20, 2015)

Thank you once more for your answers...

Yes, yes and yes I am brand new into soaping... I got an addiction this December...

I firstly read Cavich book and made tons of reading on the internet and came up with my first recipe that was an orange-tangerine juice for the water part and grounded oats... the ratio was 3:1, H2O:NaOH. The soap came out fine and tested with pH strips after a week and it was 7.

then I said, why not plunge deeper, so I made another recipe using coloidal oats, calendula infused oil and petals... this time the water:lye ratio was 2.55:1, a lye concentration of 28%. At this point I was only checking the lye concentration and since it was within the range that cavich said, I proceeded and the soap came up again just fine and pH tested... (I inserted at the end of this thread image of my soaps)...

I made in the meantime other soaps... with goats milk etc

Then, on Christmas I read caveman, that he dealt with the ratio aspect...and I said, lets work with the ratio issue... and plunged to make a 2:1 ratio this time... and I formulated a wheat, nettle soap and this one came out fine too...

I did not reproduce any recipes found... I made my own from scratch...

perhaps my misunderstanding is that you use the phrase _ lye discount_, that I dont see on the soap calc and my mind reads something else...

regarding the 1:1 ratio, I understand that it is the bottom line that someone can use, since less water than this, NaOH will not dissolve and will be caustic, but as caveman writes, please read conclusion at the attached link, that someone can play with the 1:1 ratio or 50% concentration... what I have found out (through making cyber recipes and only tweak one variable (eg. SF) at a time while the others remain constant) in order to be on the safe side, is to definatelly SF...

http://cavemanchemistry.com/WaterDiscount-Dunn.pdf

increasing SF, the amount of lye deacreases at a given recipe (Keepimg the other variables constant) ... so, on any given batch,  free lipid molecules flow around and will remain unsaponified until the end of the process... 







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Only with the 4th from a bottom I had a problem... I used for the first time EO, and eventhough I added it at the oils and blened well prior to pour the lye, either the mold or I dont know what, gave me this two phase soap...

Once again I thank you sooooooo much for your time...


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## DeeAnna (Feb 20, 2015)

"... tested with pH strips after a week and it was 7...."

Soap cannot have a pH of 7 and still be soap. The pH strips are not accurate for soap, so do not use them.

"... lye discount, that I dont see on the soap calc..."

Yes, it is most certainly there with the unfortunate name of "Super Fat" rather than "Lye discount". See section (4) in SoapCalc: http://soapcalc.net/calc/SoapCalcWP.asp. Your recipes have been using SoapCalc's default of 5% as the lye discount. 

If you click on the blue number 4 in the gray box, you will see this note: 

"...Super Fat.  Due to several possible oil variables it is safer to use less lye than needed to saponify the oils in your recipe.  This is called a lye discount and 5% is generally considered a safe number to use. Because discounting the lye by 5% leaves 5% of unsaponified oils in your soap bar this number is also referred to as super fat.  That extra 5% of superfat not only is a safety factor, it also gives the soap bar extra skin conditioning qualities because approximately 95% of the bar is soap and approximately 5% of the bar is an oil mixture that is deposited on the skin.  For more info see FAQ Number 7...."


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## Nehlena (Feb 20, 2015)

DeeAnna said:


> "
> 
> Soap cannot have a pH of 7 and still be soap. The pH strips are not accurate for soap, so do not use them.



what to use then? 

yes, believe me with the strips the color bands of the strip matched the pH 7 at the first week... But, now that you said  (5 weeks later) I went check this right minute and the pH was 9 :shock:

is it tooo high?


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## Nehlena (Feb 20, 2015)

DeeAnna said:


> "The pH strips are not accurate for soap, so do not use them.



indeed so, this is what I am reading now over the net... wow, never thought something in a chemistry laboratory used can give false results...:shock:


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## Nehlena (Feb 20, 2015)

DeeAnna said:


> "
> 
> Yes, it is most certainly there with the unfortunate name of "Super Fat" rather than "Lye discount". ."



ok, now I got it... with all of you using the lye discount name, a circuit blockaged was occuring onto my brain, because with my questions I was also considering in addition to this phrase the SF property and i could not figure out the chemistry behind this...

so, from now on, wherever I see the phrase lye discount, SF it is actually meant...






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## DeeAnna (Feb 20, 2015)

Chemists only use pH strips for a rough check of pH. High quality pH strips are reasonably accurate if used on dilute solutions that are not colloidal. 

Bar soaps and liquid soap pastes are NOT dilute solutions and they ARE colloids, so using pH test strips directly on soap is not remotely a real test of pH. But "everybody does it" in the soaping world, so I usually just grit my teeth and don't say much anymore. roblem:

Furthermore, you really want to know excess alkali, not pH, when testing soap for safe use on skin. They are not the same thing.

Soap pH (properly measured) ranges anywhere from 8 to 11 depending on the blend of fats in the recipe -- sometimes even a bit higher. You don't need to check pH, however. A zap test is actually more useful. http://www.soapmakingforum.com/showthread.php?t=30690


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## Nehlena (Feb 20, 2015)

and a zap test is better to be done after the 4-6 weeks of curing and before testing the soap in the shower?

going for the test...


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## The Efficacious Gentleman (Feb 20, 2015)

It's best to be done about 24-48 hours after pouring the soap, then at 1 week if there was a zap at the first time.  That way you can look at options available.


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## IrishLass (Feb 20, 2015)

Nehlena said:


> and a zap test is better to be done after the 4-6 weeks of curing and before testing the soap in the shower?
> 
> going for the test...


 

Speaking only for myself, I like to wait at least a week or 2 to test mine for zap, especially if the soap did not go through the gel stage. 

If one tests too soon... say right after unmolding... chances are good (especially if the soap did not go through the gel stage) that the soap may zap, which usually causes new soap-makers to unnecessarily panic and wonder their soap is ruined (no worries, it's most usually not  ). 

Waiting it out a week or 2 before testing for zap allows sufficient enough time for any slow-saponifying soap to finish saponifying and to react with the air and mellow out.

And at the other end of the spectrum, if there _is_ any zap after 1 to 2 weeks, the soap is usually still soft and moist enough at that time to rebatch it without having to add too much extra water to it to get the job done. 

In any case, for what it's worth, I don't rebatch unless the soap is still zappy after 2 weeks.

But....... from what DeeAnna has mentioned in some of her posts regarding some talks given by Dr. Kevin Dunn, I understand that a zappy soap can mellow out on its own if left to sit for many months.... I haven't tried this myself, but I just might one of these days. 


IrishLass


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## lenarenee (Feb 20, 2015)

:clap::clap:  You all should be commended for doing such a great job of persistently and patiently explaining all this, and sticking with the op as he/she learned the different between the two concepts!


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## Susie (Feb 20, 2015)

I can only speak for myself, here, but someone was patient and thorough enough to explain things to me when I was new.  That was not so long ago.  You don't get to pay people back for their time, effort, encouragement, and patience.  You can only say "thank you" and pay it forward.


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## DeeAnna (Feb 20, 2015)

"...a circuit blockaged was occuring onto my brain, because with my questions I was also considering in addition to this phrase the SF property and i could not figure out the chemistry behind this..."

I have been there, done that many times! I'm glad we are communicating better now!


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## The Efficacious Gentleman (Feb 21, 2015)

Very cool. I have had many similar experiences and I remember people helpfully helping me understand the concept.


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