A plastic bag is NOT suitable storage for extra Hot Buttered Rum mix prior to freezing.

While it looks good on paper, you need at least three hands to make it work:

1. One to hold the bag open
2. One to hold the mixing jar
3. One to scrape the mixture out of said jar into said bag

Otherwise, you end up with the crap everywhere.

Use one of those little plastic containers next time.

OR, better yet.

Buy more Rum so you don't have to store anything. :)