Here’s a great tip from Carol in Madison, WI.
“Hi, we’ve been making, using, enjoying nICE mugs for awhile now. We came up with an easy way to make nICE mugs without the annoying air bubbles that can create leaks after a little while. We fill a gallon of water and let it sit on the counter overnight. You can see the air bubbles forming on the sides of the jug. Then, the next day, we slowly pour the water from the jug into the nICE mug molds. We taped bubble wrap insulation around the base molds. The combination of the two are perfect for making clear ice glasses. We have about a dozen nICE mugs ready to go in the freezer. We love it.”