Saponification & heat

[DoctorCrowley]

I have a recipe that I've been using a while now and it makes nice soap. 45% lard, 20% CO, OO 15%, Almond oil 5%, Cocoa butter 5%, Shea Butter 5%, castor oil 5%. Soap at about 100F. My soap takes about 36-48 hours to unmold (especially on humid days) and I've noticed that when it's in the mold it never gets above 75-80F. Obviously saponification is taking place as it does harden, no lye pockets or heaviness, nice lather, etc. Family & friends comment on how much softer their hands are using this cause it's not as stripping as store bought soap. But is it an indicator of something off in my batter if it doesn't heat up more than that? I remember starting with Royalty Soaps videos and freaking out that my soap was in the 90s+ hours after I made it (haha I didn't know why it was heating up at the time). But I just want to make sure everything is ok even if it doesn't naturally heat up since that is what is supposed to happen as saponification is taking place. I want to fix the recipe if so. Thanks!

 

[Susie]

Saponification is different than gel. Gel happens with heat and will speed your unmolding. Saponification takes longer and just does not generate a whole lot of heat. I force gel on mine by using a heating pad on the bottom and insulating well.

 

[DeeAnna]

I second what Susie said! If that recipe is staying really soft for a couple of days, then my guess is it's not going into gel or you're only getting a partial gel. If you want the soap to be nicely firm at 12-18 hours, it needs to get warm enough to gel during saponification.

For example, I just got done making two loaves (14 bars each), finished the second about 4 p.m. yesterday, and they were ready to be removed from the molds at 7 a.m. today. I'll let the surfaces dry in the open air for a few hours and cut them into bars at lunch time.

"...Soap at about 100F ... when it's in the mold it never gets above 75-80F...."

Uh, this doesn't add up. If the soap batter is initially around 100 F, then the batter should be at least 100 F and probably somewhat higher by the time you pour the batter into the mold. That assumes you're making soap the way I do, which may or may not be the case.

If you're measuring the top surface temp of the soap in the mold, then, yeah, the top surface will be closer to room temperature. That is not the average temperature of the soap overall, however. You need to insert thermocouples into the soap to measure the internal temps -- that's a more valid measurement of how warm the soap is getting during saponification.

Rather than focus on the top surface temperature, feel the sides and bottom of the molded soap. I want the sides of my wooden mold to feel pleasantly and distinctly warm within an hour or so after the soap is poured into the mold. If that's the case, the soap is warm enough to gel.

If the outer edges of your soap are staying soft like clay, but the center is firm, try lightly covering the mold to retain a little more heat on the outer parts of the mold. That will help even out the firmness. Or you can use Susie's method with a heating pad, or put the soap into a cooler to trap more heat, or try a CPOP (cold process oven process) method of warming the soap. Lots of options.

 

[TheGecko]

My soap takes about 36-48 hours to unmold (especially on humid days) and I've noticed that when it's in the mold it never gets above 75-80F.

I live in the Pacific Northwest and saponify/cure my soap in an uninsulated garage. During the Winter months, it gets really damp here because of all the rain and so everything was taking twice as long. Someone recommended changing my Lye Concentration from 33% to 35%...it was only a small water reduction, but it definitely helped. You could try using a little salt or Sodium Lactate to help harden your soap for earlier unmolding.

When I first started making soap, I was told that I needed to cover my mold with plastic wrap and then wrap my mold in a towel or blanket. Mold got really hot and was still really warm after 24 hours. Then I had a disastrous experience the first time I made Goat Milk Soap...it grossly overheated, turned a nasty brown, oil separation, smelled bad. I was told to refrigerate my GMS...and my next batch was perfect. After that, I quit covering/wrapping my soap...which worked out great since I was putting my molds on the washer and dryer at the time and they were previously too hot to move, but now, no one had to wait to do laundry as I could easier pick up the molds with my bare hands and move them.

Saponification is a chemical process, not an exothermic one (again, simplifying). While heat can speed up the saponification process...like when making Hot Process Soap, it is not necessary, it just takes longer. I know a lot of folks, myself included, who make Goat Milk Soap and because the natural sugars in the milk make it susceptible to overheating, I refrigerate mine (some people put it in the freezer). After 24 hours, I pull it out of the frig and either unmold and allow to come up to room temp before cutting, or I set it sit in the mold to come up to room temp and then cut it.

 

[DoctorCrowley]

Saponification is different than gel. Gel happens with heat and will speed your unmolding. Saponification takes longer and just does not generate a whole lot of heat. I force gel on mine by using a heating pad on the bottom and insulating well.

OK thanks. I had read that saponification typically creates an exothermic reaction and was just wondering if I was doing something wrong that that hadn't been happening

 

[DoctorCrowley]

I second what Susie said! If that recipe is staying really soft for a couple of days, then my guess is it's not going into gel or you're only getting a partial gel. If you want the soap to be nicely firm at 12-18 hours, it needs to get warm enough to gel during saponification.

For example, I just got done making two loaves (14 bars each), finished the second about 4 p.m. yesterday, and they were ready to be removed from the molds at 7 a.m. today. I'll let the surfaces dry in the open air for a few hours and cut them into bars at lunch time.

"...Soap at about 100F ... when it's in the mold it never gets above 75-80F...."

Uh, this doesn't add up. If the soap batter is initially around 100 F, then the batter should be at least 100 F and probably somewhat higher by the time you pour the batter into the mold. That assumes you're making soap the way I do, which may or may not be the case.

If you're measuring the top surface temp of the soap in the mold, then, yeah, the top surface will be closer to room temperature. That is not the average temperature of the soap overall, however. You need to insert thermocouples into the soap to measure the internal temps -- that's a more valid measurement of how warm the soap is getting during saponification.

Rather than focus on the top surface temperature, feel the sides and bottom of the molded soap. I want the sides of my wooden mold to feel pleasantly and distinctly warm within an hour or so after the soap is poured into the mold. If that's the case, the soap is warm enough to gel.

If the outer edges of your soap are staying soft like clay, but the center is firm, try lightly covering the mold to retain a little more heat on the outer parts of the mold. That will help even out the firmness. Or you can use Susie's method with a heating pad, or put the soap into a cooler to trap more heat, or try a CPOP (cold process oven process) method of warming the soap. Lots of options.

I haven't had a partial gel ring yet. Typically I would put one without frosting or embeds in the oven to cpop (also depends on what time I make it and what I'm making for dinner lol). I have almost done the heating pad method but I've read so many variations on how to do it that I just haven't yet because I'm unsure of how long to leave the pad on for. I like the cooler idea too for the frosted soaps. After I mix the oils and lye water I test the temp (but before pouring in the mold) and it's cooled down to 85-90ish. I haven't checked lately though. I'll check again today when I'm making.

 

[DoctorCrowley]

I live in the Pacific Northwest and saponify/cure my soap in an uninsulated garage. During the Winter months, it gets really damp here because of all the rain and so everything was taking twice as long. Someone recommended changing my Lye Concentration from 33% to 35%...it was only a small water reduction, but it definitely helped. You could try using a little salt or Sodium Lactate to help harden your soap for earlier unmolding.

When I first started making soap, I was told that I needed to cover my mold with plastic wrap and then wrap my mold in a towel or blanket. Mold got really hot and was still really warm after 24 hours. Then I had a disastrous experience the first time I made Goat Milk Soap...it grossly overheated, turned a nasty brown, oil separation, smelled bad. I was told to refrigerate my GMS...and my next batch was perfect. After that, I quit covering/wrapping my soap...which worked out great since I was putting my molds on the washer and dryer at the time and they were previously too hot to move, but now, no one had to wait to do laundry as I could easier pick up the molds with my bare hands and move them.

Saponification is a chemical process, not an exothermic one (again, simplifying). While heat can speed up the saponification process...like when making Hot Process Soap, it is not necessary, it just takes longer. I know a lot of folks, myself included, who make Goat Milk Soap and because the natural sugars in the milk make it susceptible to overheating, I refrigerate mine (some people put it in the freezer). After 24 hours, I pull it out of the frig and either unmold and allow to come up to room temp before cutting, or I set it sit in the mold to come up to room temp and then cut it.

I swore off using goats milk my first time using it lol. now I have a bunch of goats milk cubes I just made in the freezer ready to try again I add a tsp of sugar to my lye water and let it dissolve, and 2 teaspsoons of salt as well. I was just thinking that I was doing something wrong if my soap wasn't going through a natural exothermic reaction.

 

[DeeAnna]

"...Saponification is a chemical process, not an exothermic one (again, simplifying). ..."

The chemical reaction we call saponification is indeed an exothermic reaction. In other words this chemical reaction produces a net amount of heat (in other words, the material gets hotter as the reaction progresses.)

The other end of the spectrum is an endothermic chemical reaction that absorbs heat (in other words, the material gets colder as the reaction progresses.)

****

"Gel" or "gel phase" is a physical state that soap can have. Just like water can be a solid, liquid, or gas, soap also has several physical states. The physical states for soap aren't quite as clear cut as water, but soap can obviously be a solid (bar) soap and it can also be found in various paste (gel) forms as well as a fully liquid state.

What physical state the soap will have is determined by the water content in the soap, the temperature of the soap, the fatty acids the soap is made of, and the type of alkali used (NaOH versus KOH).

For any given soap, it is generally true that a higher water content and or a higher temperature => soap is more likely to be in a gel form.

 

[Susie]

I have almost done the heating pad method but I've read so many variations on how to do it that I just haven't yet because I'm unsure of how long to leave the pad on for. I like the cooler idea too for the frosted soaps.

Heating pad method is super simple. Lay the heating pad on a temperature safe surface-I use the top of my washer or dryer. I put a thin towel on top of the heating pad. Place the molds on top of that and cover with cardboard (to prevent the next layer from touching the soap), then beach towels or an old blanket. I make sure that the towels or blanket touch the heating pad all the way around the molds. Then, turn the heating pad on high. Go back and check it every 30 minutes or so to be sure you don't have a volcano. In the winter, I do have to keep turning the heating pad back on as it turns itself off every hour or two. Once I see gel 90% or so of the soap, I turn the heating pad off and just let stay covered for about eight-ish hours. I can typically cut before I go to bed that night. About 15 or so hours after pouring. Sometimes I wait until morning just because I have too much going on in the evening.

 

[TheGecko]

The chemical reaction we call saponification is indeed an exothermic reaction.

Obviously I should have stated it better, thank you for pointing that out. Was going to change the wording, but then I saw something shiny and forgot about it.

 

[AliOop]

Was going to change the wording, but then I saw something shiny and forgot about it.

... so glad I'm not the only one...