There are two possible reasons for watery butter. 1. Your fridge just isn't cold enough to make the butter solidify properly. Stick it in the freezer to get it in good solid form. But take it out before the water freezes as well. (fat freezes more quickly than water) 2. The butter might not be solidifying because of what the cow ate, believe it or not. The saturated and unsaturated feed an animal takes in is directly related to the fat in products made from that animal. Again the fix for watery weed butter is to just put the cannabutter in the freezer for a bit.