HDPE (high density polyethylene) is freezer safe, but just like other plastics, if you freeze the contents solid, the ice expansion may deform or break it.
What do you recommend for what im trying to do? Reason why i wanted to use a bucket was so i could scoop out the ice and place it in a cone seive to strain the brew into a jar
I have used 2l soda bottles. Fill them to the top of the lable where the bottle gets smaller and freeze. Then I just invert the bottle over a Mason jar and let thaw and drain. All of the colour runs out and you are left with clear slush in about an hour.
