Mixing clay and water ahead of time, would it go bad?

[carlablack]

I have some green clay powder to use as face mask but I'm too lazy to prepare the mixture on time so I hardly ever do it. It takes a while to adjust the consistency. I also end up wasting some of it.

I was wondering, what could go wrong if I just mix a pot of clay with water and apply that paste when I feel like it? Would it go bad if it's just water and clay?

Would it not harden? Unless you keep it completely free from air.

just like other clay that’s why it’s kept damp with a cloth when you break from working with it overnight etc

I’m no expert though I could be talking complete crap!

I was thinking of a small airtight jar. What concerns me is the possibility of bacteria growing in the paste or clay losing its benefits over time.

I had a water based clay putty that remained pliable for a long time, so I guess hardening wouldn't be a problem.

It would probably separate and need to be mixed again

Mixing is fine by me, as I already use a spatula/brush to apply rather than my hands.