Cracking tops....same recipe...new problem...

[McKherring Farm]

The last five batches of soap I have made over the past two weeks have all cracked at the top. I have used the same base recipe for over a year and never had this problem with it. BUT...it has been 88-89 degrees in my house the past few weeks (I'm in the "heat dome") and my coconut oil, which is normally semi-solid, has of course turned to liquid. It is not rancid nor old, but it is liquid. Could this be what is causing the cracks? My oils are normally around 95-100F when I mix them with my lye solution, but with the coconut oil already liquid, the oil mix is closer to room temp (88-89F). The first two batches I used a new fragrance oil - BB Apple Sage - and thought that could be the culprit, but the last three I have used one of my reliable essential oil mixes - Lavender and Juniper Berry mix in one and Grapefruit, Lemongrass, and Rosemary mix in the other...and....cracks. The soap is good and I can work around the cracks, but still....any ideas about what is causing it?

For reference, here is my basic recipe that I used:

5% superfat
38% frozen goat milk
27% lye concentration

25% avocado oil
30% coconut oil
10% castor oil
35% olive oil

hardness - 35 (29-54)
cleansing - 20 (12-22)
conditioning - 59 (44-69)
bubbly - 29 (14-46)
creamy - 24 (16-48)
iodine - 61 (41-70)
INS - 148 (136-165)

I use various micas for coloring.
This is cold processed goat milk soap.

Thank you!

 

[Mobjack Bay]

It sounds like the warm weather is the problem. Do you have a fan that you can use to blow air at the mold? I’ve only had soap try to crack a couple of times but staved it off by turning on the overhead fan. I know people say to pop the soap in the frig, but my frig is always packed..

 

[dmcgee5034]

Hi! I don’t know about the coconut oil, but……. LOL @Mobjack Bay replied some of what I was going to chime in.
I had one of my soaps do this - same recipe, nothing different but I think my house was warmer. I squished it back together, put it up on cans and did the fan trick as mentioned. Hasn’t happened again, but I do feel my molds and if they are getting hot, I pop them up for a bit and put the fan on it. It’s worked good and I don’t have to use the fridge.

 

[McKherring Farm]

Normally, I put my insulated molds inside a cardboard box in my laundry room (hottest spot) but I didn't see the point of that with the heat so I left the tops uncovered and put them on the top level on my bookshelves. That was probably the wrong choice (heat rises). I will try your suggestion and put the next ones more directly under a fan. Thank you. I have only had cracks before when I was learning how to handle adding honey so this is new to me!

 

[McKherring Farm]

Hi! I don’t know about the coconut oil, but……. LOL @Mobjack Bay replied some of what I was going to chime in.
I had one of my soaps do this - same recipe, nothing different but I think my house was warmer. I squished it back together, put it up on cans and did the fan trick as mentioned. Hasn’t happened again, but I do feel my molds and if they are getting hot, I pop them up for a bit and put the fan on it. It’s worked good and I don’t have to use the fridge.

My fridge is typically not an option either! I will try the fans.

 

[KiwiMoose]

It can only be overheating. So yes - cool things down a bit. Maybe a little less castor and CO? They are both heaters. Try 25% CO and 7% castor - add the rest to your avocado.

 

[lucycat]

I make a simple shelf with two small pieces of wood set so each log end rests on one of the wood pieces but most of the log is suspended above the counter rather than sitting on it. That small open space underneath the log really prevents a lot of heat buildup. My overheating issues are with goat milk soaps and a few floral fragrances. I can prevent them if I set the log on my "shelf".

 

[linne1gi]

The last five batches of soap I have made over the past two weeks have all cracked at the top. I have used the same base recipe for over a year and never had this problem with it. BUT...it has been 88-89 degrees in my house the past few weeks (I'm in the "heat dome") and my coconut oil, which is normally semi-solid, has of course turned to liquid. It is not rancid nor old, but it is liquid. Could this be what is causing the cracks? My oils are normally around 95-100F when I mix them with my lye solution, but with the coconut oil already liquid, the oil mix is closer to room temp (88-89F). The first two batches I used a new fragrance oil - BB Apple Sage - and thought that could be the culprit, but the last three I have used one of my reliable essential oil mixes - Lavender and Juniper Berry mix in one and Grapefruit, Lemongrass, and Rosemary mix in the other...and....cracks. The soap is good and I can work around the cracks, but still....any ideas about what is causing it?

For reference, here is my basic recipe that I used:

5% superfat
38% frozen goat milk
27% lye concentration

25% avocado oil
30% coconut oil
10% castor oil
35% olive oil

hardness - 35 (29-54)
cleansing - 20 (12-22)
conditioning - 59 (44-69)
bubbly - 29 (14-46)
creamy - 24 (16-48)
iodine - 61 (41-70)
INS - 148 (136-165)

I use various micas for coloring.
This is cold processed goat milk soap.

Thank you!

If you are making cold processed soap, I think you have too much liquid. I use a 35-40% lye concentration. 1.6:1 water to lye. The other thing you can do is put the soap in a cardboard box and close it - the top of the soap is cooling off before the inside has cooled and the heat has nowhere to go, so it pushes through the top cracking it.

 

[Maple_Street_Bath]

it has been 88-89 degrees in my house the past few weeks

with the coconut oil already liquid, the oil mix is closer to room temp (88-89F)

I was told that soap cracks are caused because the outside of the soap cools faster than the inside. If the inside of the soap is still very hot, then the soap will crack to allow the heat to escape.
I would try reducing your mix temperature while your house is hot. I would say "room temp" but it sounds like your room temp is hotter than my room temp. I think you could go down to lower 80's/Upper 70's with your oil temp. You don't mention if your lye solution is hot (fresh) or if you allow it to cool. I also agree with putting your soap up on blocks or some other method to allow air to flow under your mold and even out the temperature. I do this with all of my slab molds, especially when making milk soaps. The space underneath the mold also allows me to slide ice packs underneath if I can feel the soap getting really hot. [I'm looking at you, honey soaps.]

5% superfat
38% frozen goat milk
27% lye concentration

I'm not sure what you mean by 38% GM and 27% lye concentration. Do you mean that your total liquids with GM equals a 27% lye concentration?

 

[McKherring Farm]

I was told that soap cracks are caused because the outside of the soap cools faster than the inside. If the inside of the soap is still very hot, then the soap will crack to allow the heat to escape.
I would try reducing your mix temperature while your house is hot. I would say "room temp" but it sounds like your room temp is hotter than my room temp. I think you could go down to lower 80's/Upper 70's with your oil temp. You don't mention if your lye solution is hot (fresh) or if you allow it to cool. I also agree with putting your soap up on blocks or some other method to allow air to flow under your mold and even out the temperature. I do this with all of my slab molds, especially when making milk soaps. The space underneath the mold also allows me to slide ice packs underneath if I can feel the soap getting really hot. [I'm looking at you, honey soaps.]

I'm not sure what you mean by 38% GM and 27% lye concentration. Do you mean that your total liquids with GM equals a 27% lye concentration?

Thank you for the ideas to consider. I do like your setup and will be trying something similar as well as the fans mentioned by others.

I am posting the soap cal sheet that has the information on it that I posted and that I have followed for quite a while with no issues. As for the lye solution, since I replace the water 100% with frozen goat milk, the solution itself is not allowed to warm or it would cause my goat milk to brown or even scald (I made that mistake once years ago! I'll never forget that smell.)

 

[KiwiMoose]

Gosh @McKherring Farm - I'm not sure how we all missed this last year, but is this the recipe you use? You should ideally change the 'water as a percentage of oils' setting to 'lye concentration' setting and make it 33%. Having so much water can cause overheating. In addition - you have more Lauric/Myristic fatty acids in your soap than Palmitic/Stearic, meaning that your soap is probably super bubbly BUT doesn't last long. Have you considered adding palm, hydrogenated soy, or animal fats to recipe to help with longevity?