The most liquid?

[Lin]

I was wondering what the largest amount of liquid (water alternative) amount in soap should be. Ideally in percentage of weight in oils so as to easily plug in the amount to soap calc. I've always left it at 38%, and most of my batches have had something swapped for the water. Can the amount increase higher than the amount of water you would want to be your max when using things that aren't 100% liquid? What would be the highest amount of water recommended?

I'm playing around with ideas for some soap recipes. One of them I want to make with greek yogurt and cucumber. So I'm trying to figure out what percentage of yogurt and cucumber I want to use and started wondering about how high the amount of liquid could go before bad results. I'd love to experiment, but since ingredients are expensive I prefer to think up questions and get answers from those who know when I can

 

[cmzaha]

Just replace some of your water with the yogurt and cucumber.

 

[Lin]

I will be replacing all of my water with yogurt and cucumber.

But what I'm asking is what would be the maximum amount of water you can use in making soap. And then, when you're swapping out water for something else thats not 100% liquid (like say, pumpkin where its got fiber etc in it as well) could you go higher.

On paper it would make sense to be able to use more of a product thats not fully liquid than pure water. For example if you could separate out what percentage of canned pumpkin is liquid and what is not liquid, and then match the liquid amount only to the recommended amount of water (making the total weight of pumpkin higher than total weight of water if it was being used) it would be equal to using full water and adding dry ingredients at trace.

What happens when you use too much water? From what I've seen it appears using too much water causes (in addition to longer to cure) excessive shrinking and possible malformation of the bar during (and because of) shrinking. Is there anything else?

 

[EvilTOJ]

I once added a lot of water to a particular batch by accident. At the time I didn't think anything of it. I waited almost a week to get back to cutting it, and it was like soft sticky cheese. It took about 2 months for the soap not to get goopy in the shower, and it shrank a whole lot. Nothing else has changed about it though, it's much better now.

So I think the worst that you'd get from using too much water is it takes longer to solidify, longer to cure, and more shrinkage than a winter day at the beach.

 

[DeeAnna]

You can also get emulsion failure by using too much liquid, meaning the situation in which the CP soap batter separates in the mold with an oily layer and a soap-water layer.

The practical limit that I have read about (I have no personal experience with this) is about 25% NaOH solution concentration. I regret that I do not do the "water as % of oils" thing -- it makes no sense given my chemistry background -- so you'll have to translate that on your own. I can tell you that a 28% NaOH solution concentration is roughly "full water" -- that 38% setting you're talking about.

Rather than blindly experimenting with raising the % water in the recipe, I'd stick with the "full water" thing and do the math on the water-phase ingredients to more accurately determine the amount of liquid contributed by each one.

For example, if you want to use pumpkin in a soap recipe, look at the nutritional analysis of the ingredient and try to determine the water content. That's what you want to include in the liquid contribution from the pumpkin. A 10 second look at the Google search results tells me that fresh pumpkin is 90% water, so if you want to add, say, 200 g of pumpkin to your recipe, the liquid content is 180 g and the solids content is 20 g. So plug the 180 g into the water phase of your recipe. The 20 g goes in the "additives" category just like clay or fragrance or whatever.

Hope this helps.

 

[Lin]

Thanks DeeAnna

I'm not actually planning on experimenting with this because I don't have money/ingredients to spare. Its more of a curiosity/theoretical experiment where I'm wondering if you had multiple "liquids" that you wanted to use in a soap, what would be the most you could get away with. And from that, the most different liquids you could use and still have enough of each of them to actual be imparting something to the soap. Your answer was right along what I was thinking.