Acetic acid: The main acid in vinegar characterized by a pungent odor. White distilled or cider vinegar used in home food preservation should be 5% acetic acid. (Vinegars of unknown acidity should NOT be used in home food preservation due to their unkown preservation properties.)
Altitude: In food preparation, the phrase 'high altitude' is commonly used in reference to adjustments needed to compensate for changes in atmospheric pressure relative to a specific location's elevation above sea level.
Ascorbic acid: The chemical name for vitamin C. Used in food preservation to inhibit oxidation and control enzymatic browning of cut produce. Commercially available in a concentrated form as white, odorless crystals or powder.
Blanching: The heat treatment of raw plant foods in boiling water or steam for a set period of time in order to inactivate enzymes, thus preventing the deterioration of color, texture, flavor, or nutrient content of foods.
Botulism: A sometimes fatal illness caused by eating toxin produced by growth of the bacterium Clostridium botulinum. The spores can be present in soil or debris present on raw foods. The spores can survive and grow in any tightly sealed jar of low-acid food that has not been processed correctly. Using the correct processing temperature and time to preserve low-acid foods will destroy toxin-producing spores.
Brining: The process of soaking food in a salt solution. Commonly used in making fermented pickles or preparing meat or fish for smoking.
Conditioning: After drying fruits and vegetables, some pieces may be more moist than others due to their size and placement during drying. Conditioning evenly distributes moisture among all the pieces and reduces the chance of spoilage, especially from mold.
Drying/Dehydration: The process of removing water from food.
Enzyme: A protein in foods that starts the process of decomposition. Preservation methods like canning and freezing utilize temperature (heat or cold) to neutralize the action of enzymes, which slows their activity at unfavorable growing temperatures, and helps preserve a food's flavor, texture and color.
Fermentation: Changes in food caused by the growth of bacteria, yeast or mold to produce desirable products. For example, naturally-occuring bacteria on cabbage and cucumbers, respectively, ferment natural sugars to lactic acid, a major flavoring and preservative in sauerkraut and fermented dill pickles.
Headspace: An area left unfilled above food or liquid in home canning jars or freezer containers. In canning, headspace allows for the expansion of foods and liquids when jars are heated and for the forming of a vacuum as the jars cool. Headspace also provides space for expansion in containers as foods or liquids freeze.
Hot-Pack: Filling containers with pre-cooked, hot food before processing. Since many fresh foods contain from 10-30 percent air, cooking foods before processing removes some of the air and shrinks the food, facilitating a tighter pack, reducing floating of pieces, and requiring fewer jars.
Raw-Pack: Filling jars tightly with freshly prepared, but unheated food. Some foods, especially fruits, will float in the jars using this method. Additionally, the air trapped in and around some foods may cause discoloration within 2 to 3 months of storage.