Preservation Techniques

Definition: Keeping Of perishable foods in a consumable form for a long period of time.

Dehydration: Draws moisture from the product and eliminates any medium for bacteria. Used for fruits, herbs, beans and other vegetables.

Alcohol: Alcohol kills active microorganisms. Used for fruit.

Sugar: Density of sugar retards the growth of enzymes due to a lower ratio of water. Usually 60% sugar in preserves. Used with fruit.

Liquid Cure / Brine: Submersion Of Food in a brine, an intense solution of water combined with salt and sometimes additional spices.

Pickling / Fermentation: Preserves Food by impregnating it with acid.  Vinegar is common and creates an environment that encourages fermentation. The item is generally precooked or soaked in a brine to draw out excess moisture.

Dry Cure / Salt: Surfaces are rubbed with salt and then left to cure. Usually a preliminary step to smoking, as are liquid cures.

Cold Smoking: Item is first cured, usually in a brine. Smoke is applied at a temperature bellow 100 degrees (38 degrees Celsius). Product remains uncooked. Example Scottish smoked salmon.

Hot Smoking: Cooks the product with the heat of the smoke. Item is usually cured first. Chicken, turkey, pork and trout are often hot smoked.

Pasteurization: Rapidly cooling liquid that has been heated to 180 degrees. Primarily used for milk and cream.

Sterilization: The container is sterilized before it is filled. Filled container is then brought to a high temperature. Safe for long term storage. Primarily used for canning fruits and vegetables.

Refrigeration: Enzyme activity is slowed at 32-38 degrees. Humidity level must be controlled.

Freezing: Holding temperature must be below 0 degrees. Changes the texture of the thawed product due to water evaporation.

Quick Freezing: Products are immediately cooled to -40 degrees and held at -4 degrees.

Freeze Drying: Total elimination of all moisture, repeated freezing and dehydrating. Product does not require refrigeration. Used for coffee, potatoes.

Sealing & Coating: Confit is a classic example. Today it is used more for taste than preservation.

Vacuum Pack: aka cryovac.  Eliminates all air from a plastic bag or container.