Freezing, canning, drying are all great ways to preserve food.

Freezing, canning, drying are all great ways to preserve food.

Freezing is a quick and convenient way to preserve and can be of high quality and maximum nutritional value.  


Fresh fruits and vegetables, when harvested, continue to undergo chemical changes which can cause spoilage and deterioration of the product. This is why it's important to preserve the fruit as soon after harvest as possible and at their peak degree of ripeness.  

Fresh produce contains chemical compounds called enzymes which cause the loss of color, loss of nutrients, flavor changes, and color changes in frozen fruits and vegetables.  These enzymes must be inactivated to prevent such reactions from taking place.  

Enzymes in vegetables are inactivated by the blanching process.  Blanching is the exposure of the vegetables to boiling water or steam for a brief period of time.  The vegetable must then be rapidly cooled in ice water to prevent it from cooking. Contrary to statements in some publications on home freezing, in most cases blanching is absolutely essential for producing top quality frozen vegetables. 

Blanching also helps to destroy microorganisms on the surface of the vegetable and to make some vegetables, such as broccoli and spinach, more compact.  


Pectin is the natural substance in fruit that causes the fruit juice to gel. Some kinds of fruit have enough natural pectin to make a firm gel; others require added pectin. The best type of pectin is found in just-ripe fruit. Pectin from under-ripe or over-ripe fruit will not form a gel.

Fruits containing enough natural pectin to form a gel include crab apples, tart apples, sour blackberries, sour boysenberries, most plums, cranberries, lemons and wild grapes (Eastern Concord variety). Fruits low in pectin include sweet cherries, quince, ripe blackberries, sour cherries, grapefruit, grape juice, grapes, melons and oranges. With these latter fruits, you will usually need to add pectin. Fruits always requiring added pectin are peaches, pears, figs, apricots, elderberries, strawberries, raspberries, grapes (Western Concord variety), guava and pomegranates.

Commercial pectins are made from apples or citrus fruit and are available in both powdered and liquid forms. Be sure to follow the manufacturer's directions when using commercial pectin. The powdered and liquid forms are not interchangeable in recipes.

So, how do you know if your fruit needs pectin?  There are several methods for determining if there is enough natural pectin in a fruit juice to make a good product without adding commercial pectin. The simplest and quickest is the alcohol test.

Alcohol test: Add 1 tablespoon juice to 1 tablespoon 70 percent rubbing alcohol. Mix, stir or shake in a closed container slightly so that all the juice comes in contact with the alcohol. Do not taste as the mixture is poisonous. Fruit high in pectin will form a solid jelly-like mass that can be picked up with a fork. If the juice shows little clumping, there is not enough pectin for jelly.

Get educated

Summer is a wonderful time of year for fresh fruits and vegetables and there isn't anything quite as tasty as eating the produce you raise or raised locally. Now is the time to preserve those fruit and vegetables for the time of year when it isn't readily available. Free educational brochures are available at the Extension Office to help you with your preservation efforts.  A little work now will yield great tastes later; it is very important to follow the correct procedures.

Jana McKinney is a McPherson County Extension agent for family and consumer sciences