Soaping with acidic foods-advice?

Long story--I have really been on a huge "food" soap kick and for the most part its been successful. There were 2 instances where I ran into an issue, the first being a cranberry soap, which was my own stupid fault. I was making 1/2 size of my normal batch, but forgot to measure the amount of puree so when I added it to the lye water it must have neutralized alot of the lye. That loaf looked beautiful on the outside, but when I cut it there was a layer of unsaponified fat in the loaf running the entire length. I cut it into bars, let it cure, and managed to salvage it for personal use.

Today I made a tomato soup soap for my hubby with tomato puree & powdered goat milk. I MEASURED this time 1oz of puree, and 2 TBSP of powdered milk, added at trace, everything went beautifully. I put it in my oven (not for cpop just to keep it out of the way which I always do). I check on my soaps every 30 minutes or so, they usually fully gel on their own which this one did, but it seemed a lot hotter than usual so I took it out of oven and noticed it was a lot more liquid than my other soaps would be at that point. Placed it on the table with fan on it to blow off the heat and it returned to normal color and consistency. I just cut it and noticed again excess oil, nothing like the cranberry loaf but just oily little spots on every side I cut.

Sooo is there something I can do to help prevent this when working with acidic foods? A little extra lye? A little less puree? I've successfully done other food type soaps and never had an issue until these 2 batches.

I have made 2 batches of tomato soap where I used tomato for almost all the water. I considered its acidity negligible, and I always like a good superfat, so I did not increase the lye. I could be wrong in doing that, however my soaps, both HP, came out fine.

It's because of the sugars in foods that I usually HP them. My guess is that the oily spots is related to high temp from the sugars. Have you seen this before? Do you ever freeze or refrigerate the soap when you use food?

Could it be that canned items are more concentrate in nature so less is needed? I know if I took 8oz of fresh tomato and pureed it, then compared to canned it would most likely contain more water content.

I don't think its sugar content, I made a banana loaf last week using a whole 6" sized banana pureed with coconut milk, also gelled that loaf and no issues what so ever. Have made milk & honey in past, used molasses and honey in another loaf...never an issue. So either it was too much sauce even at 1oz to the 18oz oils, or it gelled too hot too fast.

My soaps look better today so I am guessing after the normal cure period they will be fine like my cranberry bars were.

It sounds like the tomato soap overheated, I doubt it had anything to do with the acidity.

Try putting it in the freezer to prevent overheating.

What temp do you soap at? I soap at room temp and always add food purees to the soap batter. I just split my liquid for the lye and use the rest for my puree to add in after the lye. Works for me.

Guess I'll try to prevent gelling the next time I work with something food based and see if that helps.

I normally soap as close to room temp as I can get, almost never over 100 degrees but I don't measure anymore. I agree with it overheating, I have never had a soap get back to that oil consistency again when gelling so now I know. Thanks everyone!

It's interesting that other sugary things didn't heat up this much for you, so it does point to the tomato recipe being different. (unless your soaping room was a lot warmer than usual). Could it be the EO or FO you used?

Oh my gosh I'm so dumb! I was going to use one of my milky way molds which I never get a gel in, so I turned the oven on when I started getting all my stuff together to get it warm and see if I could force the gel, then turned it off when I started soaping. I changed my mind because I wanted to do a simple swirl with some clay and went for the silicone loaf mold which always gels on its own (I'm assuming since it retains heat so well). But the oven was already warmed up...not hot mind you but warm...I think I did it to myself. Whether the fragrance oil added to the heat I don't know. But I see either way, I need to be careful with the silicone and food soap additives, maybe find an open place on a shelf to not so much prevent gel as prevent it from reaching too hot temps. Hmmm...

A-ha! Mystery solved (we think). I find that a loaf shape heats up a lot--my first milk soap I put in my fridge freezer and I still got caverning/oil pockets from overheating. (it's 5.5x9 so there's a lot of middle to heat up). So yeah, that extra warmth probably affected your loaf of soap a lot.