mould on top of brine

[NCPaul]

When you start over, I'd recommend that you boil your water, pour some in your container to sterilize it, then cool the rest as quickly as possible. When the water is cool, measure out what you need, then add the curing salt mixture to make your brine.

[Big Guy]

when you make your brine don't add the full amount of water, then once it is boiled add the equivalent amount of ice to crash cool and you will still have the proper strength of brine.