Use firm ripe fruit for best flavor and set. Over-ripe fruit makes a soft set. Under-ripe fruit makes a firm set.
Buy new, flat jar lids for a good seal.
Always use clean jars. Thoroughly wash jars or containers before starting.
Use only the SURE-JELL pectin product specified for the recipes to insure a proper set. Pectin products are not interchangeable.
Measure ingredients exactly. Spoon sugar into dry measuring cups (plastic or metal). Scrape excess sugar from top of cup with a straight-edged knife. Use liquid (glass or plastic) measuring cups with a pour spout to measure prepared fruit. (Use amount of sugar specified in each recipe. Altering recipes or ingredients could cause a set failure.
Some jams and jellies may take up to two weeks to set.