It's prolly water coming from acetone evaporation (evaporation is endothermic so the mix become cold and water condensation appears) or the water was in your acetone if this one wasn't anhydrous.
Why don't you let it evaporate under a fan ? If you want to use a dessicant there are better choice than the dangerous lye. Epsom salt (200°F 2 hours in oven) for exemple
« I love the smell of boiling MHRB in the morning »