CP heating up questions

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TheBobbiesRSurly

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Hi all!

I am so close to being able to make soap again, I can almost taste it (smell it?)! Just a few more things to pick up and I'll be ready.

So I've been watching all kinds of videos and reading books for soaping. I'd say the only thing that really terrifies me still about it is the soap heating up... I don't really have any room in my freezer to stick a soap loaf for keeping it cool. But man, I'd really love to try some recipes that incorporate things like cream or different types of milks, which I know heats up the mixture.

My question I guess is - is it possible to make a milk-based CP soap without it gelling, or overheating? My fear is the soap volcano :lol:

With recipes that use beer and honey, those are absolute musts for sticking in a freezer, right?
 
I make a few milk soaps and I really like making beer soap. I never put any soap in the fridge or freezer. Ever. I know enough about heat transfer to know that's pretty inefficient and slow way to cool a loaf of soap. It might work fine with a slab mold or individual molds, but I almost always use a loaf mold. I've never had a volcano (not to say it won't ever happen, but knock-on-wood I'm doing good so far.) A few batches have cracked a bit, but that's mostly because I'm not watching close enough.

I don't soap especially cold either -- maybe 100 to 120 F (30-50 C). I never insulate my beer or milk soaps, and I put the molded soap in a cool place with no covering and good air circulation. I check the soap every 15 minutes or so for the first hour to 2 hours. My soaps usually want to gel, and that's fine with me. If a loaf of soap starts to puff up a wee bit in the center, however, it's getting pretty warm and that's a good sign it may crack. I've been known to put a loaf like that on a cookie cooling rack and set it in front of a fan. That actually works quite well. Rotate the mold every 5-10 minutes for the first 1/2 hour, so the air cools down all sides. After an hour or two, the saponification slows down enough that all should be well from then on.
 
You can freeze your milk prior to adding your lye and it shouldn't heat up that much, mine stays slightly warm, then add it to your oils. You don't have to put it in the freezer, it can be put in the refrigerator. You shouldn't end up with a soap volcano if you can keep everything around room temperature.

I put beer and honey soaps in the frig so they don't gel. I don't gel any of my soaps and haven't had any trouble when I use milks if everything is kept cool.
 
As DeeAnna and Relle say, you don't have to put the soaps in a cooler at all. They will heat up to some or other extent though, so you will need to accept that these soaps will gel or partially-gel.

If you're really super worried about overheating, there's a couple of ways to mitigate that risk other than the ones mentioned:

Use a lower proportion of additives (see toxicon's compilation of recommended additive amounts, and start with the lowest quantities: http://www.soapmakingforum.com/showthread.php?t=62691)
Use a tested fragrance oil/essential oil that you are confident won't heat your batch. Some FOs (and possibly some EOs) can make soap overheat.
Individual cavity moulds
Using silicone instead of wood moulds, as wood moulds are more insulating

One extremely cool tip IrishLass gave is that if you add your honey to your lye water rather than your oils or your soap batter, you can prevent your honey soap from overheating almost completely. I tried this on a soap that was 18% honey ppo. Although the lye water got super hot and volcanoed a bit in the jug, once it cooled off and I added it to my oils, the poured soap barely heated above room temperature.
 
If you want to prevent overheating you need to be stingy with water. When soap heats up the water in the soap expands. As the soap cools down again it contracts. The more water in the soap the more expansion when the soap gets hot. I've tested ovenprocessing soaps from the same batch but with different water content on various occasions and each time the low-water soaps have been more resistant to overheating than the high-water soaps. One of my test soaps had plenty of both milk and honey. The high-water soap fried spectacularly and the low-water soap came out perfect. http://auntieclaras.com/2015/06/overheating-soap/
 
If you want to prevent overheating you need to be stingy with water. When soap heats up the water in the soap expands. As the soap cools down again it contracts. The more water in the soap the more expansion when the soap gets hot. I've tested ovenprocessing soaps from the same batch but with different water content on various occasions and each time the low-water soaps have been more resistant to overheating than the high-water soaps. One of my test soaps had plenty of both milk and honey. The high-water soap fried spectacularly and the low-water soap came out perfect. http://auntieclaras.com/2015/06/overheating-soap/

Thank you so much for your blog post and detailed notes and experiments. I read your blog post a while back and it was because of your findings that I decided to use steep water discounts in all of my recipes with a high proportion of additives. They help me prevent gel on my milk and honey recipes, because I prefer the aesthetics of paler milk/honey soaps.
 
With recipes that use beer and honey, those are absolute musts for sticking in a freezer, right?

I'm another one for beer and honey soaps - they would have to be one of my favourites. I've never put mine in the freezer.

I usually pre-boil my beer. After it's cooled off, I dissolve the honey into it and set that into the fridge to cool.

When I make the soap, I start with everything fairly cold, even the oils. I add the beer/honey mix to my master batched lye and add them together when they're cool.

I use a thin-walled slab tray for these soaps, and set the tray by the window with a bit of netting over the soap (even a cotton cloth is too insulating I've found).

For individual moulds, which I use more for the milk soaps, I sometimes set the moulds in a tray of water and freeze that (so that the moulds are supported by the ice). Then I can set the whole lot by the window and it gets both the breeze and the ice underneath. That works a treat on really hot days here.

I do all of this because I don't like to move hot oils or soap batter about the place, especially when I'm using the slab - it gets too heavy.
 
Auntie Clara's comment about water reminded me that I should have also said I make most of my soaps with 31% to 33% lye concentration (this is not water as % of oils). Even though the soap may get just as warm as a soap with more water, a lower water soap is less likely to actually go into gel stage. This will reduce the chance the soap will crack.

From what others say as well as from my experience, the chances of going into gel are fairly low if you use 33% lye concentration. At 31% the chances are definitely more likely -- I routinely see gel in batches I do at this %.

Be sure to account for ALL sources of water -- the water in EDTA or citrate solution, any water-soluble colorants, aloe gel, pureed food additives, etc. -- because they will lower the lye concentration. I think many people don't realize this -- or they know about it but don't think a little extra water here and there is anything to be concerned about. It doesn't take a large amount of "hidden" water to affect the lye concentration, however.

For example, the last batch I did had 1600 grams of fat (about 3 pounds). Only 44 grams (about 3 tablespoons) of extra "hidden" water added to this batch would lower the lye concentration from 33% to 31%.
 
Most of my soaps are soaped at 33% lye concentration and I have to put a heat blanket over them to force gel in all but my milk soaps. Those I just put in the storage containers I use and put the lid on. If they start to show signs of overheating I remove the lid and put a fan that will blow over them. I quit trying to stop gel when I learned at 33% lye concentration slows gel. I put my molds in long flat storage containers because I fill mine to the very top and cannot cover them with anything. Plus if there is ever a problem with a volcano it will be contained
 
I have never had the dramatic overheating when I make honey soap. I usually make mine with 5% beeswax and 1 Tbsp of honey PPO. I think it's a combination of the honey AND honey FO or OMH FO that leads to really dramatic overheating. I have never stuck a loaf of soap in the freezer.

Some tips - put the mold on top of something, like 2 blocks of wood, so there is some air circulation under the mold. Your countertop can retain heat.

Have a towel underneath it so if there is a volcano, it's on a towel, not all over the counter (or glopping into your silverware drawer).

I have actually starting HPing my honey soap and I really like that. Since I use beeswax I can't soap cool when I do honey soap.
 
Good golly, this is all fabulous, amazing information!! I'm a lot more confident now about trying recipes with milks, honey, and beers added in :D Y'all have been a huge help, and now I'm back to building my list of ingredients to get (once I get more equipment :lol: ). Also I'm building a huge compilation of notes so I can feel ready when I go to do stuff.

The plan is to start with a basic recipe and get the hang of it, then move on to some 'fancier' recipes. I saw one today on instagram that used rice milk and it looked so creamy and amazing. Then I saw another one using beer and it sounded pretty darn great. I'm trying to content myself with bath bombs right now, I finally got my recipe right, just gotta tinker with colors more.
 

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