Lye issue?

[CatahoulaBubble]

So I made some lye ahead of time and stored it in a pitcher with a lid on it. I made 4 batches of it and stored it in my pantry out of direct light. I've been using it all along and I just pulled out the last batch I made and it has a really heavy crust on it. I'd seen some lye lint before in the other batches but nothing like this. It's an actual crust on the top with air bubbles underneath where I'm assuming some of the water evaporated? If I replace the amount of water that has evaporated, stir this up, and strain it can I still use it or should I toss it?

 

[DeeAnna]

Lye that's concentrated enough to make soap (28-50% lye concentration) will absorb water from the air. It will not evaporate unless you live in the Mojave Desert.

The "lint" on your lye solution is sodium carbonate (washing soda) that forms when NaOH chemically reacts with carbon dioxide in the air. It's the same dull white powdery "ash" that sometimes forms on soap bars that you can wash or steam off. So it's not like it's anything greatly out of the ordinary.

My advice -- gently mix the lye solution until all the lint is stirred into the liquid. Measure and make soap as usual. In other words, include the ash with the liquid solution. It's not that necessary to strain and discard it unless there are big lumps you can't remove by gentle stirring.

If you want to reduce your superfat a percent or two, you could certainly do that, but that's just a guess. You don't have a reliable way to know whether a superfat reduction is truly needed or not. So if you don't feel comfortable reducing the superfat, that would be fine too.