Help with cracking soap

[cmzaha]

Nope, it does not. The original liquid requirement will remain the same, no matter how much vinegar you add, whether you turn on the yes box or not. For example your liquid requirement is a total of 10 oz and you put in 10 oz vinegar. For liquid requirement will now change to compensate for the extra lye. Disregarding this small amount your printout will now tell you to use 10 oz vinegar and 10 oz + liquid. Some soapmakers will not realize they need to deduct the 10 oz vinegar causing them to use x amount to much liquid. I think it would have been better to have made a notation to deduct vinegar from liquid Not say Liquid Discount yes no. It does not deduct the vinegar from the liquid. So what is the point of the yes no? Sorry off on my tangent again

 

[AliOop]

That's very interesting, as that has not been my experience at all. When I check the Liquid Discount box, the amount of water is then reduced. As noted previously, I have to fiddle with it to get to 100% replacement, as the resulting lye adjustment for more vinegar always has the numbers off by a few grams. But I've never experienced the problem you are describing where it doesn't reduce the water at all. What could be causing this discrepancy among different users?

 

[purely soaps]

Thank you!

You can use soapmakingfriend.com instead of soapcalc, and it will adjust the lye percentage for you if you add vinegar in the additives section, and check the water adjustment box.

 

[AliOop]

Here is a screen shot from one of my recipes. It originally called for 135g water. I added 135g vinegar, checked the Liquid Discount box, and the final recipe box now shows 135g vinegar + 10.26g water. So yes, it did add 10g more water, but presumably that's because it added more lye to the recipe to compensate for the vinegar. That's where the fiddling comes in to get to 100% replacement. But I never end up with double liquid. That's so weird that it would do that to some people and not others!

 

[cmzaha]

I do find it confusing that sometimes it seems to work and other times it does not. It certainly does not make much sense. I just recommend that anyone using vinegar check the liquid numbers.

 

[AliOop]

I do find it confusing that sometimes it seems to work and other times it does not. It certainly does not make much sense. I just recommend that anyone using vinegar check the liquid numbers.

I agree, and I would prefer an option that says something like, "replace water with alternative liquid" and then let one choose the liquid. But I'm not a programmer so I'm probably underestimating what it would take to make that work.

 

[DeeAnna]

I thought there was some discussion recently about this vinegar issue and the developer made some changes. Like in the last month or so. Could your reaction be based on the "before" version, @cmzaha, and @AliOop's experience be based on the "after" version?

Also remember that vinegar is only 95% water. If the total "water" is 135 grams, and you want to do a 100% water replacement using vinegar, the weight of vinegar will be higher 135 / 0.95 = 142 grams. The extra 7 grams is the acetic acid in the vinegar.

Why it's calling for 10 grams rather than 7 grams, I'm not sure, but I haven't dug into this enough to understand the developer's train of thought.

 

[atiz]

Yes, there was a recent thread about this, but I can't remember what its conclusion was.
I have been using the vinegar function of SMF for a long time, and have never had it not recalculate the liquid if the box is checked.
What I recall from the previous discussion is that it recalculates the water as if vinegar were 100% water and not just 95% -- I have never payed too much attention to that, so not sure, but maybe that's what the developer has changed.

 

[Carl]

I'm a little late to the conversation here, but here is a copy/paste from @DeeAnna website. By the way, thanks a million for the valuable information!


"If you want to slow the rate of saponification, use more water in proportion to the alkali. This is helpful for soap that has a lot of coconut, palm kernel, or babassu oil. Without enough water, soap with these fats is notorious for overheating and cracking and sometimes even overflowing the mold like lava from a volcano. "


So based on this statement, can't I somewhat take the inverse of this statement and also slow the rate of saponification? Instead of using more water in proportion to alkali, can't I just reduce the amount of Coconut, Palm ,etc (Hard Oils) to get the same result (increasing the amount of liquid oils such as Olive)? Then the end result is my soap saponifies slower, reduces the heat, and possibly eliminates cracking.

Am I correct?

 

[DeeAnna]

Yes, but you will also change the properties of the soap when you change the proportions of the fatty acids.

I wasn't talking about all solid fats, by the way. I was only discussing the high myristic and lauric fats as being prone to overheating if used in high percentages -- coconut, palm kernel, babassu.

 

[Carl]

Yes, but you will also change the properties of the soap when you change the proportions of the fatty acids.

I wasn't talking about all solid fats, by the way. I was only discussing the high myristic and lauric fats as being prone to overheating if used in high percentages -- coconut, palm kernel, babassu.

Thanks again @DeeAnna

Another thought from my mind. Can't we also slow saponification by simply just adding more water to any recipe (regardless of the composition of the recipe)? I'm thinking about the high specific heat of water. That is why people have been using water to heat their homes for years. It holds heat for a long time and cools slowly. Slower cooling = slower saponification

 

[DeeAnna]

"...Can't we also slow saponification by simply just adding more water to any recipe (regardless of the composition of the recipe)? ..."

Um, well, yes, I think that's true. Isn't that what I said in the quote you quoted?

It's important to remember the rate of saponification can be greatly affected by other factors as well, so just changing the water content might not have as much of an effect as you might think, unless you are really careful to hold all other factors the same. Two important ones are the intensity of mixing and the soap batter temperature.

You can take this idea of increasing the water content to an illogical extreme. If you drop the lye concentration too low, the high water content will prevent the soap batter from emulsifying properly, so it's hard to keep the fat and lye solution mixed. Soap made with a 25% lye concentration is usually okay, but emulsion failures frequently happen when the lye concentration drops to around 15%.

Also there's a paradoxical effect at very high lye concentrations (low water). It seems NaOH solutions near saturation (near or at 50% lye concentration) can also slow the rate of saponification. I'm not sure if this happens for all types of soap recipes or just for some, and I can't explain why this happens, but it does happen.

We explored this idea in an SMF challenge a few years back -- I think LionPrincess was the host and we were looking at the patterns and textures that happen when soap of varying water contents are swirled together.

So I'd say the rule of thumb that says "more water = slower saponification" and vice versa might be useful within the range of 25% to 40% lye concentration. Above and below that, this rule of thumb doesn't necessarily apply.

 

[Carl]

@DeeAnna thanks again for great info.

"Um, well, yes, I think that's true. Isn't that what I said in the quote you quoted? "

Yes you did say this, but I initially thought you were only applying it to recipes high in coconut oil. I was just confirming that it was applicable to all recipes, not just those high in coconut types of oils.

 

[DeeAnna]

I understand now -- I didn't re-read the whole thread to fit your comment in Post 29 into the context of the thread, so my answer was not the best written.

I think you're going to see more of a change by increasing the water content of a high coconut soap (in other words soap high in lauric and myristic acids).

IMO, increasing the water content won't have as much of an effect if you're making soap higher in the longer chain fatty acids because soaps like that don't saponify so hard and fast, but there still will be some difference.