Excerpt from the Popular Kitchen Series magabook Canning & Preserving with permission from its publisher, BowTie magazines, a division of BowTie Inc. Purchase Canning & Preserving here.
Ascorbic acid: vitamin C in powdered form; used to prevent discoloration of light-colored fruits; can be purchased at a pharmacy.
Bacteria:naturally occuring microorganisms that can spoil food.
Blanch: briefly cooking produce in boiling or steaming water, then plunging it into ice-cold water to stop the cooking process and preserve the color.
Boil: to heat a liquid to the point that bubbles appear, and to cook food in boiling liquid. Water boils at 212 degrees Fahrenheit at sea level.
Boiling-water canner: a device that sterilizes canned food so that it can be preserved without refrigeration. Many boiling-water canners consist of a pot, lid and wire rack to hold glass jars.
Cheesecloth: a loosely woven cotton cloth originally used in cheesemaking; often used for other culinary purposes such as straining and lining.
Chutney: a food that has as similar consistency to jelly and relish, contains fresh ingredients â€“ such as herbs, fruits, spices and sugar â€“ that are combined and slowly simmered; often used as a sweet condiment with a light vinegar flavor, although some chutneys also can be spicy.
Citric acid: juice from citrus fruits, such as lemons; used to increase acidity in recipes and to prevent discoloration of fruits and vegetables.
Citrus press: a device used to squeeze juice from the citrus fruits.
Clostridium botulinum: a harmful bacterium that triggers botulism, a food-borne illness that can be deadly.
Conserves: a jamlike preserve made from fruit steeped in heated sugar mixture for a short period of time.
Fermentation: a process in which carbohydrates are converted into alcohol or acid. Under specific conditions, yeast can convert sugar into alcohol, while in other foods, bacteria ferments and produces lactic acid; pickling relies on fermentation to preserve foods.
Freezer burn: damage to frozen food caused by air exposure, which typically occurs when food has not been packaged properly in air-tight containers. The air dries out the food, causing grayish-brown spots to appear.
Freezing: a method of food preservation in which food is stored at 0 degrees Fahrenheit or below to inhibit the growth of microorganisms and the processes that deteriorate food.
Fruit butter: a fruit spread that is categorized with jams, jellies and preserves. Fruit butter doesnâ€™t require pectin, nor does it contain pieces of fruit, as it is purĂ©ed to achieve a butter-like texture.
Headspace: the empty space between a jarâ€™s lid and the food inside. In canning, leaving headspace is required, because the canned food expands during processing.
High-acid: a food with a pH level of 4.6 or less.
Hot packing: filling jars with cooked, heated food before canning.
Jam: preserved fruit pieces, usually of one fruit; the fruitâ€™s juice and pulp is combined with water and sugar and then heated, producing a soft, gelled spread in which fruits arenâ€™t distinguishable and evenly distributed. Jam does not contain liquid.
Jelly: a translucent spread made from filtered fruit juice; jellies are firm and spreadable with a vibrant color.
Juicing: the process of squeezing out juice from fruits or vegetables, often using a juicer or a citrus press.
Low-acid: a food with a pH level of more than 4.6.
Marinate: soaking food in a seasoned, acidic liquid to add flavor. Marinades usually contain vinegar, wine, lemon juice, and spices and herbs.
Marmalade: a sweet preserve that has the translucent quality and consistency of a jelly, and the texture and structure of a jam; contains chopped fruit pieces and peel; traditionally made from tangy citrus fruits.
Oxidation: a process caused by a foodâ€™s exposure to oxygen. When food is exposed to air (e.g. a sliced apple), its chemical composition is altered, diminishing the foodâ€™s nutritional value, causing discoloration and shortening the foodâ€™s shelf life.
Pasteurization: a method of food preservation in which food is heated to slow enzymatic activity and the growth of microorganisms that cause spoilage as well as to kill disease-causing bacteria.
Pectin: a water-soluble gelling agent found in fruit tissue.
Petcock: the valve on a pressure canner that controls the flow of steam.
pH: the measure of the acidity or alkalinity of a solution. Food that has a pH level of 4.6 or less is considered high-acid while food with a pH level of more than 4.6 is considered low-acid.
Pickling: a method of food preservation in which food is soaked in an acidic solution, such as vinegar or brine, to inhibit enzymatic activity and microbial growth that causes spoilage.
Preserves: a fruit spread similar to jam in which pieces of fruit are kept intact.
Pressure canner: a device that uses steam and high levels of heat to process low-acid foods.
Raw packing: filling jars with unheated or raw food before canning.
Reamer: a hand-held device used to extract fruit juice.
Relish: a pickled condiment consisting of finely chopped vegetables.
Root cellaring: storing hardy vegetables in a dark, humid environment.
Salting: a method of food preservation in which salt is packed onto food to create an environment harmful to bacteria and other pathogens that destroy food.
Screw band: a metal screw-on band that goes over the lid of a canning jar to hold it in place during processing.
Sea level: the measurement of land elevation in relation to the average height of the oceanâ€™s surface, which is the halfway point between the mean high and mean low tides. Cooking food at higher altitudes requires different cooking times.
Simmer: to cook food gently just below the boiling point (180 to 200 degrees Fahreheit).
Smoke box: a preservation device â€“ typically used for meats and fish â€“ that dries food. The smoke acts as an antioxidant, which reduces the potency of microorganisms.
Two-piece lid: the flat metal top and metal band that fits on top of canning jars to seal in food.