A soft spread that contains pieces of citrus fruit and peel evenly suspended in transparent jelly. Marmalade is cooked in small batches and brought rapidly to, or almost to, the gelling point. Marmalades are similar in structure to jam.

A glass jar that is suitable for heat processing food and/or liquids using a boiling water canner or a pressure canner. Mason jars are designed to seal with two-piece metal closures and to withstand the temperatures and reuse associated with fresh preserving. True mason jars also conform to specific shapes and capacities compatible with established safe heat processing methods and times. The jars are available in regular mouth (70 mm) and wide mouth (86 mm) styles and in capacities ranging from 4 ounces (125 mL) to 1 quart (1 L). Most mason jars have rounded shoulders, but some have straight walls. Straight-walled mason jars can be used for freezing as well as fresh preserving. See also straight walls.

Standard kitchen utensils used to accurately measure liquid or dry ingredients. Liquid measures are commonly glass or plastic and have a handle and a pour spout. Dry measures can be either stainless steel or plastic. Both types are available in imperial (cups) and metric (mL) sizes.

See screw band.

A living plant or animal of microscopic size, such as molds, yeasts or bacteria, that can cause spoilage in preserved or frozen foods.

A metric unit of volume, 1/1000th of a liter. Measures for dry ingredients are available in 1, 2, 5 and 25 mL spoons and 50, 125 and 250 mL dry measures. Metric liquid measures, usually glass or plastic, show levels for quantities divisible by 10.

Toxins (poisons) produced by some species of molds that grow on high-acid foods.