Originally Posted by
Flaneurs
If using a Tetra Pak product, put it in the water unopened and then use your normal water heater. You are essentially heating it sous vide in a Bain Marie. Just remember it takes longer to heat through than just to make the water boil. Heating to at least 165 degrees F is a good idea always.
Never heat unopened cans or other food canisters. Steam can build up inside them and the results can be explosive. This can happen quicker than one thinks.