Maxing out Rapeseed oil %

[saddigilmore]

Hello everyone,

So I have access to cheap mid-oelic rapeseed oil. I'd really like to try to turn this into some decent soap...
I also have access to pretty cheap lard.

I have access to coconut oil and castor oil, two ingredients that I bought, in preparation for making a "perfect soap" based on other things.. If I could get away with it, I'd like to save these for my "nicer" soaps that I have planned in the future.

I can play around on soapcalc all day, but I can't really start experimenting for a few weeks. The thought experiments are going wild though. ideally, I'd have two recipes that I fall onto: the one that is most economical, and the one that spares no expense to be the "best".

I can imagine that a pure 100% rapeseed oil soap would not be ideal. But could anyone, if anyone has made this, say why? I know that the single oil tests covered canola, and it was a VERY soft bar, but does this carry over to rapeseed?

How different are they? Rapeseed vs Canola, in terms of soapmaking? I hear that rapeseed oil is more resistant to DOS than canola (even though they are related). I don't know the validity of this claim, but if anyone has any experience making soap with this oil....

Assuming that the Oelic acid content is similar, would rapeseed oil still be more resistant to DOS?

If I wanted to use a recipe like 60% rapeseed, 25% lard, 10% coconut oil, 5% castor oil, would the inclusion of the coco and castor actually be noticeable in such low quantities? would it be a waste?

I'd love some insight. Thank you all!

 

[The Efficacious Gentleman]

My last batch was
50% lard
30% coconut
15% sunflower
5% castor

I have made it with lower coconut (I think 20% would work, but not sure I went that low) and more of the sunflower, and you could well replace the sunflower with rapeseed - just do not plan on leaving bars around for years and years if you're using oils prone to going rancid.

As for castor, that 5% is worth it, very much so. But I 100% suggest you make a batch with it and without it, so you can see for yourself

 

[ResolvableOwl]

10% coconut oil, 5% castor oil, would the inclusion of the coco and castor actually be noticeable?

Yes. The coconut oil, for one, will make the bar harder and cure quicker, so that many steps (emulsion/trace/saponification, unmoulding, cutting, drying, curing) are easier and less time-consuming. It also gives off abundant, fluffy lather, that complements well the creamy, silky (but also low and slimy) lather of canola/rapeseed oil.
Castor is a “lather booster” that works wonders to increase frothing.

Both are not strictly necessary, but (as you can see from many recipes) highly appreciated by the majority of soapmakers. But there are other/complementary ways to increase lather. Addition of sugar/honey/sorbitol into the lye water is popular. Similarly, many replace the water by other liquids like aloe vera juice, coconut milk, dairy milk (goat, cattle, buttermilk, yoghurt), etc.

A caveat with the wording of your question: Addition of anything is only noticeable (in the strict sense) if you can compare it with something where it isn't present. If you don't mind the extra effort, try out both (one batch pure rapeseed/lard, one with coconut and castor added) and compare them in their soapmaking/curing behaviour, lather and cleansing performance, skin feel, and price.

Would you consider lard a hard oil?

Yes. You have to somehow get palmitic+stearic acids in your recipe, and lard is an abundant source of either.

I hear that rapeseed oil is more resistant to DOS than canola (even though they are related).

How different are they? Rapeseed vs Canola, in terms of soapmaking? Assuking that the Oelic acid content is similar, would rapeseed oil still be more resistant to DOS?

I don't have access to/experience with rapeseed (inedible, high-erucic), so I'm merely judging from the soap calculator numbers, that they appear pretty similar.
The more important number wrt DOS than oleic acid content is the sum of linoleic+linolenic acids (PUFA). It is good practice to keep them not too far above 15% in the total recipe. In this respect, inedible rapeseed (22% PUFA) looks slightly better suited to soapmaking than kitchen-grade canola (30% PUFA). However, these numbers vary wildly between origins and varieties of the rapeseed plants.

When fine-tuning a recipe with inedible rapeseed oil (or crambe/camelina/mustard), keep in mind that most soap calculators ignore its high content in erucic acid, which behaves similarly to oleic acid, but isn't accounted for.

 

[saddigilmore]

Both are not strictly necessary, but (as you can see from many recipes) highly appreciated by the majority of soapmakers.

If you don't mind the extra effort, try out both (one batch pure rapeseed/lard, one with coconut and castor added) and compare them in their soapmaking/curing behaviour, lather and cleansing performance, skin feel, and price.

I think this is one of those cases, where I feel 100% comfortable blindly trusting people with more experience than myself, rather than being stubborn, and having to find out the hard way, and being stuck with bars of soap nobody wants to use. I was fully prepared to include minimum 10%coconut oil and minimum 5% castor oil in every soap I ever make, based on all the reading I've done on this topic. and this cemented it.

The rapeseed oil in question I have access to is food grade, I guess it's safe to assume it should be similar to food grade canola??

What is the highest% of rapeseed/canola oil would you feel comfortable using? if lard, coconut oil, and castor oil were in the mix?

If I went with something as high as say... 60% rapeseed, 25% lard, 10% coconut oil, 5% castor oil, at a low superfat% (or even 0% sf) with no other additives, (this ratio has a Linoleic at 10% and Linolenic at 5% according to soapcalc)

This question was asked in the canola oil thread... am I still at a high likelihood of DOS, even if the sum of linoleic+linolenic acids is ~ 15%, with 0% superfat, with such a high rapeseed oil content (more than 15% is considered high, right?)?

thank you again for the replies, I really appreciate the expertise

 

[ResolvableOwl]

If I went with something as high as say... 60% rapeseed, 25% lard, 10% coconut oil, 5% castor oil, at a low superfat% (or even 0% sf) with no other additives,

Go for it! It's a sound recipe, though not for the impatient (slow trace, better give it an extra day until unmoulding, and then plenty of cure time). It won't be hardest, longest-lasting bar of soap you can imagine, but it will lather nicely, and feel gentle to the skin while still cleaning well. Anything beyond the 85% rapeseed/lard is perfectly justifiable as functional additions. And as @The Efficacious Gentleman indirectly pointed out, 10% of coconut are a low amount, close to the minimum that makes sense to add at all. No reason to have a bad conscience . Also, if it is somehow easier for you to get palm kernel oil, you can replace the coconut with it.

Regarding “no other additives”, I'd at least recommend you to add some citric acid/sodium citrate/lemon juice. Easy to obtain, it helps against soap scum, and is a building block in the fight against DOS as well.

Would you say this is true even at zero or negative superfat? Theoretically speaking?
I would have thought that if there's no unsaponified oil left that would lead to less or no DOS?

This question was asked in the canola oil thread... am I still at a high likelihood of DOS, even if the sum of linoleic+linolenic acids is above 15%, with 0% superfat?

Difficult to tell. For first, I'm (thankfully!) not a great expert in suffering from DOS. My worst experience was from a HP soap bar with 60% canola, that was fully saponified at about 0% lye discount, and had cocoa butter as late superfat, so (at least on paper) no unsaponified linoleic oils. Still terrible DOS. Ever since, better safe than sorry (that usually means keeping PUFA<20%, ROE, citrate).

 

[The Efficacious Gentleman]

Aye - and if you do find it lacking something, I usually add salt at 2% of the oil weight and sugar at 3% of the oil weight, both dissolved in the water before I add the NaOH - salt helps with hardness and sugar helps with bubbles/lather. Both can be relatively inexpensive compared with increasing coconut oil or such

Edit to add, I know you said no additives, but these two might be worthwhile

 

[ResolvableOwl]

(Just a bit of shameless self-promotion about my background with high-linoleic oils/soaps in general, and canola in particular)
https://www.soapmakingforum.com/threads/grocery-store-soap-challenge.83534/page-5https://www.soapmakingforum.com/threads/linoleics-anonymous.83688/https://www.soapmakingforum.com/threads/conceptual-soap-opera.83798/post-887616

 

[saddigilmore]

Ever since, better safe than sorry (that usually means keeping PUFA<20%, ROE, citrate).

I don't wanna buy more ingredients!! I think the moment I see a spot, I'd jump on this boat. I wanna see if I can get away with this one, first.

I usually add salt at 2% of the oil weight and sugar at 3% of the oil weight, both dissolved in the water before I add the NaOH - salt helps with hardness and sugar helps with bubbles/lather. Both can be relatively inexpensive compared with increasing coconut oil or such

These are additives, but ones I already have in my house. I'd give these a shot!
Do you think sugar has an effect on DOS? I imagine that salt would inhibit it, but I'm unsure about sugar. It's a preservative, but also a food source. I'm confused about it. But everyone says it adds to lather, so that is quite important I'd say. Shaving time off of everything w cure time and stuff, with the salt, sounds like a pretty nice idea.

 

[ResolvableOwl]

AFAIK, DOS is a purely chemical reaction (not biological in the sense that microbes are involved), so sugar doesn't matter in this respect (neither does salt). In fact, soap naturally contains quite some glycerol, which is in its way a sugar too, with all the bug-food implications.

Do your thing! Be happy about your soap, and use it up generously within a few months after it has finished curing. And keep a bar or two for long time observation (how it feels and lathers 1 or 2 years later etc., if it goes rancid or not). Don't be sad if it catches DOS, on the contrary. In fact, how to learn better how (and how long) recipes work well for you?

 

[cmzaha]

In my own personal opinion, I would Not use over 20% Canola or Rapeseed oil. I use a lot of HO or Mid Oleic Canola but never over 20%. Canola as a single oil soap makes a lousy soap, slimy and less lather than even a pure Castile soap, even after a very long cure. This includes Zany's no slime recipe which I had no success with, going dossy within 6 months. I have issues with high lard going dossy so a high Lard percentage and high Canola/Rapeseed formula would spell disaster for me. I like 25/35-40% Lard/tallow or 25/3540% Lard/Palm with Canola at 15-20%.

 

[saddigilmore]

This includes Zany's no slime recipe which I had no success with, going dossy within 6 months. I have issues with high lard going dossy so a high Lard percentage and high Canola/Rapeseed formula would spell disaster for me

I have to try it anyway. I really wonder, if we should all be posting our weather/curing conditions, with our recipes. A rough estimation of temps and humidity, or something. The fact that the same recipe is giving ppl 2 year old bars, or giong dossy in 6 months, using the same recipe, is driving me crazy!

 

[saddigilmore]

Someone talk me out of this (80% rapeseed, 15% coco, 5% castor, 0%SF, salt+sugar in liquid)

Is this a GUARANTEED case of DOS? Waste of Lye, water, time, energy, space, oil, molds?

 

[KimW]

I won't talk you out of that recipe and, yes, of course you have to try it!
I'd be a bit concerned of it without Citric Acid, but I understand why you would leave it out. Come to think of it, I have to correct myself in the other similar post and say I did not use CA in my Store Challenge soap because I didn't buy it there.
ETA: From my previous post, "faux seawater" is salt and baking soda.
If you have some sort of starch to add, it should help give some hardness to the bar.

Doing some reading, it looks as though "rapeseed" oil is for industrial use and canola oil is the same oil, but edible. Yes? Just want to understand with the point of saying your results will likely be very similar to mine, though I did add CA to my 100% Canola bars.

Forgive the country reference. This is just the first good search hit:
https://www.aveno.be/2019/11/difference-between-canola-and-Rapeseed-oil.html#"In some countries, the term ‘rapeseed oil’ is used to refer to the oil for industrial use, whereas ‘Canola oil’ is used to refer to the edible cooking oil. However, in Belgium, ‘rapeseed oil’ is usually used interchangeably for both and the term ‘Canola oil’ is not really used at all."

 

[earlene]

The other suggestion I would make is to go for a lower superfat setting with a more DOS prone oil. I'd start with 3% SF if you are worried it might not be safe, but I've used 0% many times and never had lye heavy soap (zap-free) even at that setting. Oh, I see you already are doing 0% in your most recent post.

If you want a harder soap, and don't want to buy other oils, but have rice in your pantry, I'd suggest using rice water as a lye water substitution. For some reason, rice seems to harden soap extremely well. Boil some rice in some excess water & save the water to use as water replacement in your soap. If interested, you can also purée some overcooked rice & incorporate that into your soap at trace and that also makes for an even harder bar of soap. The soap won't last longer in use, but it will remain more firm when dry than soap without rice.

I've used rice purée in Rice soap with the purée being 25% and 50% of the liquid. In both cases, the soap got surprisingly hard. With the 25% rice purée soap, I also used rice water (congee, actually) but only 40% water replacement. And my hard oil to soft oil ratio was 23:77; saturated:unsaturated ratio was 31:69. Your recipe has a sat:unsat ratio of 16:84 and hard:soft oils ratio of 15:85. Your hardness number is 16; mine was 31. In spite of that hardness number, which is almost double yours, the soap started out really soft, but during cure became much harder.

Not as hard as the soap I later used 50% rice purée as water replacement. But I also used more rice powder in that soap as well and a bit more hard oils, too.

But based on my experience and what @Dawni reports, adding rice in some form, and preferably multiple forms will harden your soap. It won't prevent DOS, or make it last longer in use but it will harden your soap.

ETA: Dawni is the Rice Soap Queen here at SMF. See her thread on Triple Rice soap.

 

[cmzaha]

I have to try it anyway. I really wonder, if we should all be posting our weather/curing conditions, with our recipes. A rough estimation of temps and humidity, or something. The fact that the same recipe is giving ppl 2 year old bars, or giong dossy in 6 months, using the same recipe, is driving me crazy!

All my bars are dried on a rack in a low humid area and all bars are made with a combination of 0.5% each EDTA and Sodium Gluconate at the rate of 1% total batch weight. I will note I make a lot of brine (Soleseif) soap and Salt bars with no issues so I really contribute the issue to the baking soda. I am not the only one here that has had a failure with that recipe and it does not make a slime-free bar.

I will highly recommend if you are going to go 80% Rapeseed/Canola you use a good chelator such as EDTA or Sodium Gluconate, which I find more efficient than ROE or Sodium Citrate (reacted Citric Acid), which I used before changing to EDTA/SG combination.

 

[saddigilmore]

it looks as though "rapeseed" oil is for industrial use and canola oil is the same oil, but edible.

I don't know, I think it varies based on geography. But the rapeseed oil I get here is definitely edible, it's sold for cooking @ the supermarkets. From what I understand, canola is genetically engineered rapeseed. This makes me think they should behave similarly, but that's a big assumption. They must have enginneered some differences into it, or else it wouldn't be distinct. and these differences could show up in soapmaking. Who knows... not me! LOL but I'm going to find out!!

If you want a harder soap, and don't want to buy other oils, but have rice in your pantry, I'd suggest using rice water as a lye water substitution. For some reason, rice seems to harden soap extremely wel

oh boy... I do have rice... but this is getting into a realm of additives that I didn't want to walk down. adding 1-2% salt and 2-3% sugar or something by oil mass is relatively straightforward... I'd hate to have differences in starch content be another variable

I will highly recommend if you are going to go 80% Rapeseed/Canola you use a good chelator such as EDTA or Sodium Gluconate, which I find more efficient than ROE or Sodium Citrate (reacted Citric Acid), which I used before changing to EDTA/SG combination.

I know you're right. Everyone that recommends these things to me, did so out of their own trial and errors. However, I think I have to learn this one the hard way. Your curing seems on point.... I'm just hoping I'm one of the lucky ones? Some people never see orange spots. I want to know why people are getting different results with the same recipe. This kills me

Unless I see an orange spot with my own eyes, I don't want to believe! I'm walking into this prepared to fail but I am reading and taking all your suggestions to heart, for when I eventually fail, I know what to change

 

[KimW]

I dig your forthrightness, @saddigilmore and I can't wait to see and hear about your soap!

 

[ResolvableOwl]

I don't know, I think it varies based on geography. But the rapeseed oil I get here is definitely edible, it's sold for cooking @ the supermarkets. From what I understand, canola is genetically engineered rapeseed.

I initially didn't know you're based in Europe/Germany. Canola is (or, initially was) a brand name for Canadian GMO rapeseed oil, that (AFAIK) never was sold in Europe. The name diffused to edible (low erucic) rapeseed oil in general. That means that both statements are right: “Canola is a brand name for edible GMO rapeseed from Canada” and “In Europe, you can buy non-GMO, low-erucic food-grade rapeseed oil cheap in every supermarket”.
It's a mess. But is it important? Yes! Inedible “rapeseed oil” (high erucic) and edible “canola oil” (low erucic, both GMO and non-GMO/conventional breedings) have different saponification values. Online soap calculators, invented across the pond, exist in a different market, and call the same things differently. Here is a German SAP table that states “Rapsöl (Brassica oleifera)” NaSAP=0.1354 much closer to “canola” 0.133 than “rapeseed” 0.125.
Using a too low SAP would have meant excess superfat – which you arguably want to avoid.

 

[saddigilmore]

But is it important? Yes! Inedible “rapeseed oil” (high erucic) and edible “canola oil” (low erucic, both GMO and non-GMO/conventional breedings) have different saponification values. Online soap calculators, invented across the pond, exist in a different market, and call the same things differently. Here is a German SAP table that states “Rapsöl (Brassica oleifera)” NaSAP=0.1354 much closer to “canola” 0.133 than “rapeseed” 0.125.
Using a too low SAP would have meant excess superfat – which you arguably want to avoid.

This is definitely important!! So the calculator I prefer has canola (I assume Low-O) , and HO canola.... the rapsol I'm using is, from my understanding, Mid-O. Which should I choose in my soapcalculator?

Thank you so much- I would have surely chosen the "rapeseed" option, and ended up with some unwanted superfat! This is why I'm waiting a week to do this experiment gotta work out the kinks first hahaha. But for all intents and purposes, our german rapeseed is equivalent to everyone else's canola, in terms of SAP values... I wonder if it has the same "dossy" properties

 

[ResolvableOwl]

Roughly speaking, the content of oleic acid by itself is the only uninteresting parameter of an oil/fatty acid profile. All other fatty acids (palmitic/stearic, lauric/myristic, linoleic/linolenic, ricinoleic) bring distinctive properties into a soap, and the rest is just filled up to 100% with oleic acid (in some sense).

In soap, the kitchen, and industry, high-oleic is not a quality by itself. Rather it implies low in poly-unsaturated fatty acids (linoleic and worse), which impart longevity and heat stability (DOS danger in soap, frequency of deep fryer oil changes, resinification). This thread is about sunflower oil, but applies to rapeseed varieties (within their tighter limits of PUFA variation) too. The typical cheap Rapsöl you get in German supermarkets has some 25…30% PUFA, which limits its worth as a major bulk oil in soap (Don't ask me where I know this from).

BTW: In oils with varying PUFA content, the degree of unsaturation has next to no impact on the saponification values: hydrogen atoms are light, missing hydrogens (double bonds, unsaturated chains) don't disturb molecular weight much. What has a major impact with ****/canola is the different content of erucic acid, that has a carbon chain that is longer by four heavy carbon atoms than oleic acid.