Recommendations change as scientists learn more about what is safe and what isn’t.
The other day, I stopped at a convenience store to fill my vehicle with gas. A nationally produced canning book with a colorful, attractive cover beckoned me. I plucked a book from the shelf and quickly paged through it as I awaited my turn in line.
The author talked about “great-grandma’s recipes” and provided recommendations for canning based on yesteryear. I am interested in food history, so that aspect caught my attention. Unfortunately, the processing times for several foods would not be considered safe by today’s standards.
If my great-grandma were alive, she would not want me (or you) to be sickened for the sake of nostalgia.
I should have bought all the books to take them out of circulation, but the books were fairly expensive. Buying them just prompts the publisher to reprint them.
If you decide to preserve foods, be sure to use the most up-to-date resources for safety. Compare old recipes to new research-tested formulations; some might be OK. Other recipes have changed as more research in home canning is done.
Let’s take a trip back in food preservation history. According to food historians, the earliest method used to decide if food was edible was trial and error. Let’s call it “Plan A.” Making a mistake about edibility had dire results.
The survivors then developed “Plan B.”
“Plan B” involved observing animals. If animals ate the food and survived, chances are you would, too. You could get quite hungry and tired observing animals before trying an unfamiliar food, so there was a need for “Plan C.”
Because food wasn’t always available when you needed it, “Plan C” involved preserving familiar foods. Most food preservation techniques likely were discovered by accident. If you lived in the desert, the sun and wind naturally dried your food. Frigid areas of the world offered natural walk-in freezers.
Fermentation was discovered somewhere along the historical line. Wild yeasts and other microorganisms naturally present in the air fell on fruit, causing the sugars to ferment into alcohol. Someone tried it and liked it, maybe too much. Wine was the result. Sauerkraut and yogurt had similar beginnings.
Pickling, curing with salt and preserving with sugar to make jams were other discoveries that extended the shelf life of foods throughout history. Canning foods had its beginnings in the 1790s when a Frenchman, Nicolas Appert, heated food in glass bottles and noted that the food didn’t spoil as quickly. Scientists, including Louis Pasteur, later learned much about microorganisms and their relationship to food spoilage and developed other preservation techniques.
Much of the research about home canning took place in the 1940s and continues today. Recommendations change as scientists learn more about what is safe and what isn’t.
Many of my great-grandma’s recipes probably are no longer considered safe, even though generations of relatives may have survived eating the food. Tomato varieties, for example, have been bred to be less acidic to appeal to our tastes. Great-grandma’s famous canned stewed tomato recipe might have dire results using today’s tomato varieties.
Preserve food safely with these general rules for safe canning:
Use a pressure canner and current U.S. Department of Agriculture processing guidelines to can low-acid foods, such as vegetables and meats.
Acidify tomatoes with the recommended amount of bottled lemon juice or citric acid prior to canning (1 Tbsp. of bottled lemon juice per pint of tomatoes; 2 Tbsp. per quart). Be sure to process the tomatoes for the recommended time.
Use research-tested salsa recipes and don’t alter ingredient proportions. If you create your own salsa and want to preserve it, freezing it is the safest option.
Seal jams and jellies with a regular canning lid (not wax) and process in a boiling water bath for five to 10 minutes, depending on altitude.
Free food preservation resources (canning, pickling, making jams and jellies, drying, freezing) are available at http://www.ag.ndsu.edu/food.
If you are new to home food preservation, consider making jellies or jams, such as this refrigerator fruit spread, as a starting point.
Uncooked Berry Jam
2 c. crushed strawberries or blackberries (about 1 quart berries)
4 c. sugar
1 package powdered pectin
1 c. water
Yield: About five or six half-pint jars
Sterilize canning jars and prepare two-piece canning lids according to manufacturer's directions. To prepare fruit: Sort and wash fully ripened berries. Drain. Remove caps and stem; crush berries. To make jam: Place prepared berries in a large mixing bowl. Add sugar, mix well and let stand for 20 minutes, stirring occasionally. Dissolve pectin in water and boil for one minute. Add pectin solution to berry-and-sugar mixture; stir for two minutes. Pour jam into freezer containers or canning jars, leaving 1/2-inch head space at the top. Close covers on containers and let stand at room temperature for 24 hours.
To store: Store uncooked jams in refrigerator or freezer. They can be held up to three weeks in the refrigerator or up to a year in a freezer. Once a container is opened, jam should be stored in the refrigerator and used within a few days. If kept at room temperature, the jam will mold or ferment in a short time.
On average, 1 tablespoon of fruit jam has about 50 calories, 0 grams (g) of fat, 0 g of protein, 13 g of carbohydrate and 10 milligrams of sodium.
(Julie Garden-Robinson, Ph.D., R.D., L.R.D., is a North Dakota State University Extension Service food and nutrition specialist and professor in the Department of Health, Nutrition and Exercise Sciences.)
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