Introduction: Beverage Insulator
To keep your favorite beverage cool, convert an inexpensive vacuum container. Discard internal lid if equipped. Center and drill a snug hole in the cap such that the bottle is firmly held. This will reduce condensation on the inside and slow heat transfer even in the hottest environment.
Step 1: Optional Liner
Take up extra space with sponge drawer liner cut to size. This step will reduce noise and improve fit.
Tip, store your container in the freezer just before use and the first will be as cold as the last.