Yes. One test I use often is to drop about a teaspoon of jam on a glass plate and stick it in the refrigerator for 5 minutes or until it cools (you can also stick it in the freezer for several minutes to make the process quicker). Once you remove the plate from the fridge or freezer, take the tip of your finger and tap it. If it is set properly, it won't stick to your finger or run down plate when you tilt it. If it hasn't set yet, continue to simmer until it's ready.