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Garden Gives Me Joy

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Jan 25, 2020
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United States
I want to attempt dish soap paste that is kept in a bowl at the sink. This is my recipe.

PKO, 100%
Caustic Soda(s): NaOH @ 80% and; KOH @ 20%
Lye concentration @ 35%
Caustic soda discount @ 0%. (MIght consider something like -0.5%, if useful)
Glycerine @ 5%
SG @ 1%

Since my location has a highly humid tropical rain forest climate, should I worry about bacteria being attracted to glycerine? Can the softness of a paste make this problem more likely? If I must use a preservative, what type is best (and food safe)?

I usually adjust caustic sodas to account for Citric Acid. If this is necessary for SG, how much SG neutralizes NaOH and KOH please?
Nov 15, 2018
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With that amount of NaOH and PKO, I don't think that this will end up being a paste. Even with the added glycerin, it will be pretty hard - closer to a solid bar that is just a tad soft. That could still work for a dish soap, but if you want to achieve a paste consistency, I'd start at 80% KOH and 20% NaOh, and skip the glycerin.

The 0% SF or -1% SF sounds good. SG doesn't affect lye, so no adjustment needed there. Some of the dish cake recipes I've seen use a preservative, and some don't. I'd be inclined to make a small batch without it and see how it goes. Or make a big batch, but only keep a small amount by the sink at one time. The rest of the paste can live in a nice dry, dark location until you are ready to refill the container by the sink.

Would love to hear what you end up doing and how it turns out! I typically make dish paste with syndets (SCI and CapB), and I have not used a preservative in it. All good so far, but I'm typically the only one using that paste, and I make sure there is never any standing water in the container. Your conditions might be very different and could warrant a preservative.