HP soapers.....a question for you

[szaza]

@SaltedFig I'm glad you like my lengthy updates! I hope I'm not hijacking this thread..

You know what the weird thing is? The coconut oil soap with 30% SF gelled super fast without extra heat (30min), while the wheat germ oil at 0% superfat didn't go through gel completely, even though I had it in a very warm oven for quite a while (gave up after about 1,5 hours). So I don't think the superfat is the culprit of slow saponification in this case.

I actually did the high superfat with the coconut oil on purpose to keep the amounts of lye and water the same as with the wheat germ oil batch. I had read a bunch about the influence of water on saponification and gel phase, but couldn't find anything about the influence of the type of fat. I thought I'd have an experiment comparing wheat germ oil with CO with exactly the same amount of water and lye (that was the only way to keep both lye:water concentration and water as % of oils the same) to see the effect of the choice of oils on the speed of saponification and gel phase. I think the big difference in speed of saponification between the two suggests that hard oils are easier to gel than soft oils and that could be the reason why I didn't get the wheat germ oil (or the soap I made yesterday) to gel without added heat. But there could indeed still be other explanations! And it could also just be a one-off or something.

I opened a new can of NaOH on wednesday, so that can't really be the problem. I do agree that the small batch size could have had a huge influence on these outcomes. I imagine a smaller batch loses heat more quickly. I also didn't measure my temperatures, so maybe my coconut oil was just a lot hotter than my wheat germ oil.. I tried to have everything the same and the oils felt equally hot to the touch, but at that temperature it is hard to distinguish between 80C ouch and 90C ouch

 

[BrewerGeorge]

Hmmm... Interesting! Do you have any idea if it is possible to know the concentration of the newly produced lactic acid? I have a hard time finding sodium lactate, so maybe adding lactic acid to the water before adding lye could be an alternative but it would be useful to know the concentration of LA to know how much extra lye to add to compensate for the lye neutralized by the lactic acid.
I'm imagining the LA concentration (by weight) could be similar to the concentration of sugar in the original substance you feed the bacteria on (hoping my biology is not failing me... 1 molecule of glucose is converted into 2 molecules of LA, which is half the molecular weight of glucose, so if the bacteria don't use or produce any other substances the weight of the LA produced should be about the same as the weight of the glucose you started with) but I'm really not sure if that theory holds up in real life.
I'm not even sure if it's a good idea to try to make my own lactic acid to make sodium lactate, but I think it's interesting to explore the possibility

You're on the right track. I haven't tried this where the exact amount was important; I've just used it to make Berlinner Weisse a few times.

Lactic acid for beer brewing is supplied as 88% solution, and it's pretty cheap.

This too. I love this stuff. I dilute it to typical acetic pickling strength and use it to make fake fermented pickles. You get that soft lactic twang without having to mess with the actual ferment.

 

[szaza]

Thanks for the info @BrewerGeorge ! Very good to know.. I'll probably go for ready bought lactic acid first, for safety and precision matters. But who knows where experimentation might lead..

Looking back at the last few posts, I've pretty much hijacked this thread haven't I..
I'll start a new thread for the coconut oil vs wheat germ oil experiment and leave this thread alone for a while
I am curious though.. @Holly8991 how are your experimentations going? Did you end up trying countertop HP or not (yet)?

 

[Holly8991]

I haven't tried it yet but I am going to sometime this week. My daughter flies back to school tomorrow so I will need something to really keep me busy.

 

[psfred]

Coconut oil saponifies quickly and generates heat I think, that's probably why it gelled so quickly.

 

[psfred]

To get fast saponification and the "volcano" you must use high heating oils like coconut. Otherwise it's faster than regular HP, but not the "instant finished soap".

Always always always run your recipe through a lye calculator and double check. I also suggest using fresh sodium hydroxide, no container will seal tightly enough to prevent some water absorbtion and reaction with CO2 from the air.

I suspect the "countertop" process works better at near zero superfat, and it's quite easy to add some extra later as a calculated amount (that is, reserve some fat for superfat). Just like regular HP.

Enjoy your experiments, it's the best way to learn!

 

[grandmary]

I do HP and My soap volcanoes every time. Sometimes once but up to 3 times. It always stirs down. Its how I know the lye is doing its job. I also soap around 190. I don't remove mine from the heat though

I do hp this way all the time now. you can't get many designs but I just do an itp with white and one color. It works every time. I don't use any dairy at the end, just my regular recipe w/goats milk. I use the eo or fo to loosen it a bit at the end. You have to be ready to get it in the mold fast but my bars come out beautiful every time. each batch takes a different time even though I use the same recipe. It usually takes me about 30 or 40 minutes but my best time is 14 minutes start to finish. I soap it hot (about 200) and I keep the crock on high. You can't look away even for a minute. I also keep a tray with sides under my crock just in case. and yes it has boiled over one time, but only one time when I was distracted for just a second. Now I ask hubby if he needs anything before I put in my lye.

 

[KimT2au]

Sorry, newbie question here. Gosh, I hate asking such basic questions, but you are all so generous with your knowledge. Does the adding of sugar and dairy affect the shelf life of the soap at all? How long do you need to set aside soap made by this method before it is ready for use?

 

[psfred]

I don't think dairy or sugar has much impact on shelf life of soap. HP still needs a six week cure, it's just saponified completely a couple days faster than CP, the rest of the "cure" process is the same.