Kelly Davidson's booth at a farmer's market in the winter features canned goods from produce on her farm.  GRETCHEN MENSINK LOVEJOY/SPRING VALLEY TRIBUNE
Kelly Davidson's booth at a farmer's market in the winter features canned goods from produce on her farm. GRETCHEN MENSINK LOVEJOY/SPRING VALLEY TRIBUNE
Rural Wykoff resident Kelly Davidson has mastered the art of glass-jarred home food preservation, a practice reminiscent of grandmothers and late summer sunshine.

"There are two ways to can - pressure and hot water bath," she explained. "I started canning in 2003 by reading the Mirro book that comes with the pressure canner with a jiggler gauge...probably tomatoes," she said.

She began canning for her business, Prosper Valley Farm, the same year she learned to can fruits and vegetables, recommending quite glibly that those who take up the practice should know that 4.6 is the pH - or acidity level - that determines whether one should use a pressure canner, a large vat with a sealed lid that induces pressure on a covered jar in order to ensure its own seal. The reason is that doing this instead of a hot water bath, or jars simply set in an unpressurized pan of boiling water, to seal food into quart and pint jars is due to safety issues related with hot water bath canning, namely that "it only takes once to kill someone" if bacteria isn't eliminated inside a jar.

"I started with fruit...strawberries, elderberries, all jams, jellies, syrups and lots of black and red raspberries. Most fruit is under 4.6pH and can be sold at markets - pickles are under 4.6 pH because of added vinegar, lemon or lime juice, so I can sell cukes, relish, pickled beets at farmer's markets, but tomatoes and most vegetables are not to be sold at markets because they are potentially hazardous."

Davidson has been pleasantly surprised by what she can can, some of it actually for her own use and enjoyment. She has even done some meat, too, namely chicken and venison. She said meat worked great, as it was very tender, like tuna in a can.

One year, she tried pumpkin, but the jars got all bubbly and the tops popped open, so she found that it's best to freeze pumpkin. Rhubarb jelly is a fun one, though, she added.

"I have made a lot of mistakes, broken jars, had cloudy brine in jars after canning and learned that you must use perfect fruit and veggies," admitted Davidson. "I don't use alum because it's cloudy, and the best tip for pickles is to pick and can in the same day...I can't wait until tomorrow. Fresh is best."

This year, Davidson has about four acres of veggies and fruit, and she also has a 72' by 30' high tunnel so that the growing season is extended in the spring and fall. She uses "maybe 500 or so" canning jars each season, and they're always at the ready for the coming harvest so that she has time to go to markets around southeastern Minnesota and sell her produce.

"My kitchen is set up for canning - if your market sales are over $5,000 per year, you are required to use a federally inspected kitchen. One pressure canner does it all. I hot water bath pickles every day in August and September. The walls are covered with shelves filled with clean jars in all sizes. The jars are washed in winter so they are ready for summer canning. There's definitely no time to wash jars in summer."

Davidson added that she needs to can almost every day in August and September to stock shelves for the winter market. She does lots of pickles of all kinds for holidays, beets, peppers, watermelon rinds, sweet relish, cukes, garlic baby dills, slicers and wholes, salsa using approved recipes on the Department of Ag website, but not a lot of salsa because it's labor intensive.

Given that she's constantly canning throughout the summer, one would think that she would keep quite a few canned goods for herself, but she actually doesn't because the goodness of summer is in demand at winter farmers' markets.

"I keep tomatoes when I have time, but mostly what I keep is in the freezer, and I use the dehydrator to save tomatoes, garlic, herbs such as basil and cilantro, rosemary, thyme and mint," she said.

The Wykoff woman says she is "really too busy" getting through the canning season right now to teach others how, but she feels that she "should teach a class in the winter, at community ed or something."

She enjoys canning "maybe because everything looks so colorful in jars in the dead of winter...spicy pickled veggies in a two quart jar is like art and looks beautiful on the Thanksgiving table." Davidson particularly enjoys opening a jar of preserved vegetables or fruit midwinter and tasting summer.

"Yum, and it's handy because you don't have to go to the grocery store in cold weather. It's got good flavor, too," she said. "Fresh is still best, but I like watermelon rind pickles just like Grandma used to make. I am still waiting for the melons this year, but those are really different and good. The older folks remember watermelon rind pickles. I also do dilly beans with big pole beans."

And when Davidson finds herself in a winter jam (or a pickle), she just thinks of all her different jam flavors: black raspberry jam or jelly, black raspberry rhubarb jam, Concord grape jelly, elderberry jelly, strawberry jam, elderberry syrup, raspberry jam, raspberry-rhubarb jam, raspberry jelly, strawberry rhubarb jam, wild grape jelly, and triple berry jam made of red raspberries, strawberries and gooseberries.