This master recipe works well with a variety of summer berries. The thickness of the syrup will depend on the berries you use: Some are juicier, resulting in a thinner syrup, while others, like blueberries, have more pectin, yielding a thicker syrup. If you prefer to skip the canning process, you can store the covered jars in the refrigerator for up to 2 weeks; to extend the shelf life, follow the canning instructions below.