AY Honors/Food - Canning/Answer Key

1. Define the following:

a. Botulism

is a rare but serious paralytic illness caused by a nerve toxin, botulin, that is produced by the bacterium Clostridium botulinum. Foodborne botulism is caused by eating foods that contain the botulism toxin. Outbreaks of foodborne botulism are usually caused by eating contaminated home-canned foods.

b. Steam pressure canning

is a method of canning by placing the food in a pressure cooker. A pressure cooker allows water to be heated to a temperature higher than the "standard" boiling point of 212°F (100°C).

c. Boiling water bath

d. Steam canning

e. Open kettle canning

f. Pectin

Under acidic conditions, pectin forms a gel, and it can be used as an edible thickening agent in processed foods. This effect is used for making jams and jellies.

g. Hot pack

Food is packed into jars after being cooked and while still hot. It is then placed in a pressure cooker.

h. Cold pack

Food is packed into jars in an uncooked state (or sometimes after being scalded). It is then placed in a pressure cooker.

i. Sterilize

Killing all forms of bacteria and other pathogens present on an item (such as a jar).

j. Scald

Immersing a fruit or vegetable in boiling water for a minute or two. This splits the skin, easing the task of removing the peel.

k. Jelly

A jelly is a sweet or savoury food gel, usually made through the addition of gelatin or pectin to edible liquids. "True" jellies are smooth textured and made from fruit juice, such as grape jelly.

l. Jam

is a type of sweet spread or condiment made with certain fruits or vegetables, sugar, and sometimes pectin. In the United States and Canada, jams are invariably made from mashed or ground fresh fruits.

m. Marmalade

invariably refers to a conserve derived from a citrus fruit, most commonly from oranges. The recipe includes sliced or chopped fruit peel, which is simmered in fruit juice and water until soft; indeed marmalade is sometimes described as jam with fruit peel.

n. Pickles

Pickling is the process of preparing a food by soaking and storing it in a brine containing salt, acid (usually vinegar), or both, a process which can preserve otherwise perishable foods for months. The resulting food is called a pickle.

4. When should food be steam pressure processed?

Foods that are low in acid have a lower pH level and do not contain enough acid to prevent the growth of botulinum bacteria. These foods are processed at temperatures of 240 - 250 degrees F, attainable with pressure canners.

6. Can the following items:

d. One jelly or jam

You can make jelly or jam from almost any fruit you like. Strawberry, blackberry, raspberry, grape, and plum are all excellent choices. We present a recipe for plum jam here.

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Sterilize enough jars for the jelly you are going to make. This can be done by washing them in hot, soapy water and rinsing in bleach water, or by boiling them.

A mix of ripe and nearly ripe plums will work well for this recipe. Wash the plums, place them in a large pot and cover with water. Heat until the plums become soft and squishy and the skins break open. Use a slotted spoon to transfer them to a chinois or a china hat. A chinois is a cone-shaped sieve with a mounting stand and a cone-shaped pestle. Place a large measuring bowl under the chinois and use the pestle to crush the plums through the holes in the straining cone, catching the pulp in the measuring bowl. The skins and seeds will be left behind. Take note of the amount of pulp obtained, pour it into a large pot and add an equal volume of sugar. Stir in the sugar until it is dissolved, and heat the mixture to a boil. When it begins to boil, reduce the heat and let it boil for 20 minutes. Do not reduce the heat so much that the mixture stops boiling, and monitor it carefully, stirring often. If dark colored sauce can be dislodged from the bottom of the pan when stirring, reduce the heat a little more, as this is an indication that the sauce is burning.

After 20 minutes, pour the mixture into jars and seal them. It should gel in about 20 minutes.