Jam on It!

Notes of a Preservation Proselytizer


Story by Christina Ward
Photographs by Jenny Bohr

I’m an evangelist. A googly-eyed true-believer who will chat your ear off about the alchemical magic of canning. I see summer reborn every time I open a jar of claret-colored strawberry jam.  I taste the hard labor of tomato picking in a sturdy quart of marinara sauce. I even itch with the memory of fighting off the blasted mosquitoes and biting ants for the triumph of wild blueberries from Marinette County. My best and most lasting memories are those spent with my grandmother on her farm outside Osseo, Wisconsin. She directed the picking of strawberries, told us stories while we hulled, then transformed those little red devils into best tasting jam I’ve ever had.  Does that make me a foodie? Or just crazy?  For many of us who love food and the art of growing and making delicious meals, preserving the harvest bounty is a logical next step.

The essence of all food preservation is the arresting of decay and the blocking of food-borne pathogens. Through the advance of science, making your own jams, jellies, and pickles has never been easier. In my classes, I always describe the process as both simple and complex.  There are rules to know and understand, procedures that must be followed; but within those boundaries is where the magic happens.

Wisconsin summers hold the promise of berries. First the strawberries, then the raspberries, blueberries and blackberries. The natural sugar and moisture content make them delicate to keep fresh once picked, and are perfect partners for preservation.

Have you slathered homemade jam on your toast? Or just eaten a guilty spoonful right out of the jar? Did you purchase a jar of preserves on your last vacation, that so captured your memories of the place that you would argue with anyone that jam indeed has as much terroir as wine? Did your grandparents make it? The memories of hours of cleaning strawberries around a table can be the legendary stuff of a lifetime of family stories.

What is Food Preservation?

What is Preservation actually? And how do these basic ingredients end up with such different results? That’s the magic of preservation. All food decays. The enzymes in the fruit start work as soon as the berry is picked. Some decay can be good; think fermentation. But often it is bad and negatively affects the taste, safety and nutritional quality of the food. So the first step of Food Preservation is stop the enzymes from doing their thing. Two things stop enzymatic action: Heat and Cold. Pick one. If you pick Cold, you’re on a path to making a fresh jam. If you pick Hot, you’re making cooked jam.

The second aspect of preservation is preventing “the Ick” from invading your jam. The Ick are the legion of pathogens that would like to take up residence in your food. See, they think it’s as tasty as you do!

Two generations ago food preservation techniques were handed down through families. As more people moved away from agricultural lives to automated, urban ones, that knowledge faded away.

There is a beauty to the mechanics of nature. The climate that we as humans enjoy is the same that pathogens find ideal. Their requirements for life are the same as ours. They (and us) need the right amounts of moisture, temperature, acidity, and oxygen. The most basic tenet of food preservation is this: change one (or more) of the ideal conditions for life and you will stop any “the Ick” from contaminating your food.

So think of it this way: Are you in a pickle? Well, you’re in an acid (vinegar) bath and it’s uncomfortable. Pathogens don’t like it either. Feeling dried out when you eat too much salt or sugar? Sugar and salt absorb moisture; when sugar is used in a jam, the pathogens are deprived of moisture. Love jerky snacks? That’s the salt removing the moisture from the meat. Once we understand the basic science of making your food safe, we can experiment with flavors.

What’s the last requirement for “the Ick”? Same as for us: oxygen. That’s where the Hot-Water Bath Processing or freezing comes in. The hot-water bath process, of submerging nearly full jars in a boiling water bath for prescribed time, is what drives any oxygen out of the jar and creates the anaerobic environment. And when the jar is sealed, without oxygen, we’ve completed the safe preservation of the food. We’ve deprived the pathogens of their ideal environment and made it safe and delicious for us to store and eat.

variouspickleditemsThere are challenges to Hot-Water Bath Processing. You need a few specialized pieces of equipment. Very necessary is a Jar Lifter, a canner or large stock pot with rack, canning jars and two-piece lids. These items require some investment; about $50 to get started. The major producer of home canning equipment in the United States, Ball/Kerr, offers a Canning Discovery Kit that costs about $15 for those who want to dip their toes in the boiling water.

Two generations ago food preservation techniques were handed down through families. As more people moved away from agricultural lives to automated, urban ones, that knowledge faded away. Learning the correct and safe methods for preservation may seem overwhelming without direct experience. Take heart! Canning is enjoying a resurgence. Look for classes that will help you hone your skills.

Freezing can also create a low-oxygen environment. It reduces the temperature so as to create the low-oxygen atmosphere, but there can be drawbacks to long-term freezer storage: a lack of freezer space, power outages, decrease in nutritional value during storage, decrease in taste quality.

The choice of preservation is determined by a number of personal criteria. In many cases, freezing is best for short-term storage and preserving small amounts, while Hot-Water Bath Processing is best for large batches of items for longer-term storage.

Make Some!

If you’re new to canning, making a berry jam is a fun first lesson in learning the art and science of food preservation. (See sidebar for State of Wisconsin-approved Freezer/Fridge Jam recipe.)  In exploring canning, there are a few rules to follow. As intuitive as it is to cook and eat food, there are scientists working to make our food preparation practices as safe as possible. The concern I hear in my classes most often is about safety. Asking “How do I know it’s safe?” is the number one question everyone should ask when looking at a home-canned item. Everyone has a story about Aunt Mabel’s cousin’s friend who got sick from a bad pickle. These urban legends hold a grain of truth insomuch that jam made sloppily and lazily will make you sick.

To that end, the University of Wisconsin recommends that you use only tested recipes published after 1994. A good source for these recipes is the Ball Blue Book and the State of Wisconsin Extension website. If you have an old beloved family recipe, contact your local Master Food Preserver at your County Extension office; we can give it the once-over a few times and recommend a safer alternative.

If you’re ready to try your hand at Hot-Water Bath processing, I recommend taking a class to help orient yourself to the steps. Many people have said that they feel much more confident in making and processing their own jams when they’ve had the chance to do it hands-on in a classroom versus just reading about it. And it’s a great way to meet people in your community who are interested in canning. There is an ergonomic equation at work here, too: many hands make light work! Finding a ‘canning buddy’ is a great way to put up preserves fun and efficiently.

Farmers Markets

Southeast Wisconsin is rich in Farmer’s Markets. Come the summer there are markets every day of the week. Farmers are the best source of fresh and local fruit. If you’re ready to embark on a jam project, talk to them. Many farms offer “Pick Your Own” fields where you will enjoy the labor of finding the perfect berries. Other farmers will sell you larger amounts if they have it available. Make friends with your farmers; they’ll like you too!

If spending a hot day in a field picking elusive berries isn’t your idea of a good time, many markets feature folks selling jams, jellies and pickled items. There are two types of makers represented in this category. There are people producing in commercial kitchens, which are subject to inspection and regulation by the State. And folks selling under the Pickle Law.

prettypicklesIn 2011, Wisconsin passed what is colloquially named the Pickle Law. The Pickle Law states that home producers, with the proper training and documentation, can sell their home-canned jams, jellies, pickles, salsas and sauces at local farmer’s markets. This is part of the nationwide movement of local food production and gives both the maker and consumer opportunities to connect. The benefits of buying locally produced items are many: support of small makers, use of local ingredients, no chemical preservatives, and unique flavors. But there can be pitfalls as well. Buying from a maker authorized under Pickle Law means that the consumer needs to be informed. And that means asking questions.

Makers selling under Pickle Law are required to have each jar labeled with every single ingredient the product contains listed from largest to smallest amount by volume. They must also provide their home address and phone number on each jar label. Makers need to keep a running inventory and batching log that tracks each jar, and when and how many were made per batch. Makers need to keep this log with them and will show you if asked.

The majority of makers love what they do. They want you to love it too. So ask the questions, you’ll probably get more information than you expected! If anyone balks at answering, you can choose not to purchase. Just as you would look sideways at a jar of jelly given to you by Aunt Mabel with the 77 cats and that “smell,” use common sense when making decisions about purchasing processed food. Here are some things to look for and ask yourself: Is the jar fully sealed? Is there any discoloration on the surface of the product? Is there an ‘off’ smell when the jar is opened? Do I trust the origin of the product; does it have all the correct labeling and contact info? Was the seller friendly and straightforward answering my questions? The rule with any suspect food is: When in doubt, throw it out. Always err on the side of caution.

When we make conscious choices about what and how we eat, we are doing more than spending money. We are creating our family, our community. We are building on something that harkens back to our primal roots as humans, the gathering and preparation of food that won’t kill us. Yup, I’m an evangelist.  I want everyone to can something this summer. I promise you it will be the best <jam, jelly, pickle, salsa, sauce> you’ve ever eaten.

Must be Jelly ‘cuz Jam don’t shake like that!

canningSo you see the jars lined up. What’s the what? Here’s the lowdown on the classification of preserved fruit:

Jelly – Is made from only the juice of the fruit.

Jam – Made from the pulp of the fruit.

Marmalade – Uses the rind of citrus.

Conserve – Contains nuts and/or dried fruit

Butter – Pureed, cooked whole fruit with little added sugar; thickened by cooking reduction.

Preserves – Usually referring to whole fruits suspended in thickened juice.

Chutney – A sweet/savory condiment containing fruit.

Curd – A thickened spread usually made with citrus juice and egg yolks.

Where to find out about canning classes in the Milwaukee area:

Recipe: Strawberry Freezer Jam

Tested and approved recipe from the State of Wisconsin Extension Office (for a lower-sugar jam).


  • 4 cups crushed strawberries
  • 3 cups sugar
  • 1 cup water
  • 1 box (or 1/3 cup) low-sugar pectin (Pomona or Sure Jell)

Prepare Fruit:

  • Sort, wash, remove stems/hulls from berries; crush.

Make Jam:

  1. 1. Measure crushed berries into large bowl
  2. 2. Measure sugar into a large saucepan. Stir pectin into sugar until thoroughly mixed. Stir in 1 cup of water.
  3. 3. Bring mixture to boil on medium-high heat and boil constantly for one minute. Stir constantly! Remove from heat and skim off foam.
  4. 4. Stir fruit into hot sugar/pectin mixture. Stir for one minute or until thoroughly mixed.
  5. 5. Pour quickly into freezer safe containers, leaving 1/2 inch headspace (room from top). Cover tightly then label and date.
  6. 6. Let stand overnight at room temperature then put into freezer. (Freezer life is one year.)
  7. 7. Thaw in refrigerator for use. Can be refrigerated for up to 3 weeks.

Makes 6 half-pints.


ChristinaWardChristina Ward is the certified Master Food Preserver for Milwaukee County. She teaches canning classes, volunteers in the community, and sells interesting jams and jellies at a local farm market.  She lives is a fifth-generation Bay Viewite whose heart still mucks along the creek of her gramma’s Osseo farm.  She spends as much of her summer as possible at an old family trailer in Marinette County.  She also makes crazy stuffed animals and quilts. You can find her on Facebook at Kick Out the Jams.

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