Graduating to a slab mold w/ brine soap - need advice


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Nov 7, 2018
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Hi all, thanks in advance for your help!
I've been making CP soleseife in individual silicone molds and it's worked well.
I'm moving up to a (aprox) 6 lb slab mold with guidelines cut in the wood for cutting within the mold when it's ready to cut.
Recipe here...questions after...
68.45 oz olive oil pomace (60%)
34.22 oz coconut oil (30%)
5.7 oz shea butter (5%)
5.7 oz castor oil (5%)
16.18 oz lye (5% superfat)
30 oz total (20% brine) water
I haven't used my slab mold before but I've calculated out what I think should be the right volume above.

First question: lining the mold...
I bought oversized heavy duty quilt template plastic and would like to make a permanent mold liner out of it if it would actually work. The thing is that I'd have to remove the side pieces of the liner (4 separate pieces - 1 for each side with the largest square piece staying on the bottom of the mold while cutting) to use the cutting knife that came with the mold. It's intended to cut the bars while the slab is still in the mold. Do you think if I cut the plastic accurately, that the sides could just be laid against the walls of the slab mold without taping them to each other. I guess what I'm asking is if it would cause a leak problem if they were put in the mold independently of each other. That way, when I cut the bars, I could just lift out the side liner pieces and then use the knife to cut the bars while the slab is still in the mold. Otherwise if I couldn't remove the side liner pieces, the knife wouldn't be able to cut through the slats in the mold since the liner would be in the way. Does this make sense?

Question 2 and super important:
When is the best guess about when should I cut the slab into bars so they have the best chance of successful cutting? This is the question that's keeping me up at night.

Thanks very much!!!


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Sep 15, 2018
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I can answer your second question. Recently I had missed my window to cut a soleseife loaf and it was rock hard after about 6hrs. I since tried again and unmolded after 2, cut around the 3rd hour and it's all good. Both soaps are in the gallery if you want to see how bad it is to be unable to cut on time lol

I guess depending on your weather and climate, it could be more or less than that.

Best to keep checking. When I unmolded my second try, it had the give of soft cheese, like if I pressed down I'll get a dent. When I cut about an hour later, if I really pressed down I'd get a shallow dent. But both were still technically soft. Hope that helps.