August is green bean season, and that means one thing: dilly beans.

It’s August, and if you have a garden, chances are good that it’s going gangbusters right now.

That’s good news, but it can be overwhelming, too. There’s a reason the old adage exists, the one about making sure to lock your car doors during zucchini season so that bags of the prolific, polarizing vegetable aren’t furtively dropped inside.

Thankfully, though, for all those folks who are finding themselves with more tomatoes, green beans and other produce than they know what to do with, Kathy Savoie, a professor with the University of Maine Cooperative Extension, has some tips to help Mainers safely preserve summer’s abundant harvest to enjoy it during the rest of the year.

Whether it’s salsa, sour pickles, jams, jellies or tangy dilly beans, which she said many refer to as the “olive of Maine,” Savoie loves preserving food at home from the produce she grows in her garden. She also loves teaching others about food preservation.

“Personally, it’s a large interest of mine. It’s something that I always did, and something I grew up doing,” she said. “And it’s an area that I’ve seen grow significantly from a public interest standpoint, as local foods have become increasingly popular.”

Canning safety is paramount

That growing interest is exciting to her, but she cautions people to be careful as they expand their repertoire of canning and preserving. Cutting corners or taking shortcuts on recipes is not advised, because the risks can be great. Three years ago in Ohio, improperly canned potatoes used to make a salad at a church potluck led to an outbreak of botulism, a deadly form of food poisoning. One woman died, and more than 20 other people were sickened after attending the potluck supper. Closer to home, a few people became sick several years ago after eating home-canned tomato sauce in Washington County.

Stories like those underscore the importance of taking care when canning food, Savoie said. She oversees a program at Cooperative Extension that t rains master food preserver volunteer s, who then act as community liaisons to help others learn how to properly can food. To get involved in the program, interested cooks must be over 21, attend a 10-part, 35-hour course and be willing to complete at least 20 hours of volunteer service. Applications for the 2019 program will be available in mid-March.

One of the first things to learn is to follow recipes that are tested by food safety experts. To get the best information and safest canning recipes available, home preservers are encouraged to go to tried-and-true sources such as the Cooperative Extension, the United States Department of Agriculture or the National Center for Home Food Preservation.

“It’s very important that people get their recipes from a reliable source,” Savoie said. “We want to make sure that people are getting the most current information as well.”

Credit: Abigail Curtis

Tomatoes and beyond

One easy food preservation option is to freeze your produce. Even whole tomatoes can be washed and then popped into a freezer bag to be kept on ice until wanted. Other vegetables, such as green beans and broccoli, also can be frozen but they should be blanched, or dropped briefly into boiling water, before plunging them into an ice bath to immediately halt cooking. They can them be put into the freezer.

But if cooks want to explore canning, they should know that canning works to preserve foods by using heat to kill any microorganisms that cause vegetables and fruits to spoil. By using proper canning techniques, heat forces air out of the jar, and as the jar cools a vacuum seal is formed which stops the growth of microorganisms and preserves the food.

The highest risk in home canning is low-acid foods that are not properly processed, she said, such as fresh green beans (not dilly beans) that are processed in a boiling water bath rather than a pressure canner. Acidic foods, such as pickles, relishes, jams and jellies, on the other hand, can safely be processed in a water bath.

One thing that home cooks may not know is that although tomatoes are usually considered acidic, they still need additional acidification to safely can in a water bath. Cooks should choose disease-free, vine-ripened, firm fruit for canning, according to the National Center for Home Food Preservation, and then add 2 tablespoons of bottled lemon juice or half-teaspoon of citric acid per quart of tomatoes.

“People often forget to acidify their tomatoes,” Savoie said, urging cooks to double-check their process to make sure they preserve food using the best information possible.

Home canners should then pack tomatoes into hot, sterile canning jars, leaving a half-inch of head space at the top of the jar. They should then remove the air bubbles, wipe the rims of the jars, adjust the lids and process in a boiling water bath canner. Savoie noted that it’s important to use the right type of jars for home canning and also to always use new lids. Once food has been canned, it should be used within a year, and once the jars have been opened, they can be stored in the refrigerator for up to two weeks.

“That’s oftentimes a surprise for people, to learn that the jar of relish has a two week window,” she said. “What hasn’t changed is the expression: ‘When in doubt, throw it out.’”

Pickled Dilled Beans

Yields about 8 pints

4 pounds fresh tender green or yellow beans (5 to 6 inches long)

8 to 16 heads fresh dill

8 cloves garlic (optional)

½ cup canning or pickling salt

4 cups white vinegar (5 percent)

4 cups water

1 teaspoon hot red pepper flakes (optional)

1. Wash and trim ends from beans and cut to 4-inch lengths.

2. In each sterile pint jar, place 1 to 2 dill heads and, if desired, 1 clove of garlic.

3. Place whole beans upright in jars, leaving half-inch headspace. Trim beans to ensure proper fit, if necessary.

4. Combine salt, vinegar water, and pepper flakes (if desired). Bring to a boil.

5. Add hot solution to beans, leaving half-inch headspace.

6. Process pint jars for five minutes in a boiling water canner (or for 10 minutes if your altitude is higher than 1,000 feet).

Recipe courtesy of National Center for Home Food Preservation

Standard Tomato Ketchup

Yields 6-7 pints

24 pounds ripe, washed tomatoes

3 cups chopped onions

¾ teaspoon ground red pepper (cayenne)

3 cups cider vinegar (5 percent)

4 teaspoons whole cloves

3 sticks cinnamon, crushed

1½ teaspoons whole allspice

3 tablespoons celery seeds

1½ cups sugar

¼ cup salt

1. Dip tomatoes in boiling water for 30 to 60 seconds or until skins split, then dip tomatoes in cold water.

2. Slip off skins and remove cores.

3. Quarter tomatoes into 4-gallon stock pot or a large kettle.

4. Add onions and red peppers. Bring to a boil and simmer uncovered for 20 minutes.

5. Combine spices in a spice bag and add vinegar in a 2-quart saucepan. Bring to boil. Cover. Turn off heat and let stand 20 minutes.

6. Remove spice bag and combine vinegar and tomato mixture. Boil about 30 minutes.

7. Put boiled mixture through a food mill or sieve. Return to pot.

8. Add sugar and salt, boil gently, and stir frequently until volume is reduced by one-half or until mixture rounds up on spoon without separation.

9. Fill pint jars, leaving 1/8-inch headspace. Adjust lids and process jars for 15 minutes in a boiling water canner (if you are canning at an altitude higher than 1,000 feet, you will need to process for at least 20 minutes. The Cooperative Extension has precise instructions on how to do that safely.)

Recipe courtesy of University of Maine Cooperative Extension

BDN writer Lauren Abbate contributed to this report.