Cornstarch is a common kitchen staple that is readily available and easy to work with. It's the perfect ingredient to make strawberry jam without pectin. Moreover, using cornstarch allows you to have more control over the thickness of the preserves, as you can adjust the amount during the cooking process according to your preference. Another reason why cornstarch can be considered a better option for thickening strawberry preserves is its neutral flavor. Pectin, while effective in creating a gel-like consistency, can sometimes introduce a slightly "cooked" taste to the preserves.