Yes, soda ash can be hard & crusty.Thank you for all that info!
I am just concerned about selling them. I obviously don’t want to get sued!
I will look into those images but is soda ash ever hard and crusty? Also, our basement (where the soap is) flooded and so it’s super humid (and made some of my soap sweat!) so if lye does absorb water would that mean it’s absolutely not lye? Why did it hurt my tongue? Also, how would air bubbles be crusty?
Why did it hurt your tongue? Did you lick it directly? Or did you follow the suggestions of how to Properly & Safely conduct the Zap Tongue test?
https://www.soapmakingforum.com/threads/how-to-properly-safely-conduct-the-zap-tongue-test.63199/Do you have a 9-volt battery on hand? I suggest you compare what that feels like to the Zap you get from your soap, but make sure to follow the directions in the thread I linked. Please report back if you do both those things and let us know your result.
Air bubbles would not be crusty as far as I know, but I didn't suggest that.
If your soap gets sweaty and still has what looks like that sort of snowflake-like flake or what you are calling a crystal, then, no, it can't be a NaOH flake. NaOH pulls water to itself.
Test that out yourself and take a few lye flakes or beads out of your dry lye bottle & sit them in a dish of a with enough color contrast that you can see clearly what happens. Then set it out on the counter open to the air. If your air is humid, the lye will get wet eventually. I cannot say how long this will take, as it will depend on how humid it is in the area where you put the dry lye & how long it sits there. It would happen faster in a bathroom that is used frequently, or in a kitchen with a pot of boiling pasta, and less slowly in an Air Conditioned room and even slower in a room with a dehumidifier. But it would eventually happen.
Of course if you do try this test, be sure to monitor the left-out-in-the-open lye and ensure that any pets, children or other living creatures in your home do not come into contact with it.
Good luck and let us know if you try these things.