Will sugar-free gelatin set if canned pineapple is added (used to be no way!)?
Gelatin (whether sugar-free or with sugar) will set with added CANNED pineapple. You’ve mixed up the fact that you can’t use gelatin with FRESH or frozen pineapple. Fresh or frozen pineapple contains an enzyme that dissolves the proteins that bind together and make gelatin solidify. To use fresh or frozen pineapple in gelatin recipes, you first have to heat the pineapple, which kills (or negates) the enzyme. Then you can proceed with your recipe. Bon Appetit!