Demystifying Canning

When it comes to preserving the seasonal bounty of the Hudson Valley, it is imperative to have a conversation about canning. Why is this important to know? Well, everything has a season and a shelf life. That includes fruits, veggies, meat and fish. Canning allows us to enjoy seasonal ingredients all year long, such as taking fresh apples and turning them into apple butter.

Visiting your local farmers market to buy ingredients at the peak of freshness and ripeness is fun, delicious and supports the hard-working people who produce these goods for us. By learning the tricks of the trade (such as canning), you can build a sustainable pantry and even enjoy summer strawberries in winter.

In a way, canning is like taking a step back in time to honor history and a much simpler way of life. The methods of preserving ingredients by way of canning harkens back to our ancestors who didn’t have the luxury of refrigerators and major supermarket chains. Driven by necessity and a lack of modern amenities, our ancestors developed canning methods we still use today. Canning allowed them to create shelf-stable foods that could feed their families delicious, nutritious meals all year long. That’s a truly sustainable way of living.

Canning also played a role in developing world cuisines we all know and love. Canned tomatoes of Italy. Sauerkraut, made from cabbage in Germany. Kimchi of Korea. Dilly beans from the Southern United States. They all have a deeper meaning that goes beyond flavor. They have a taste of the past.

Farm2ChefsTable Sauerkraut

In modern times, canning makes seasonal foods that would otherwise have a short shelf life accessible any time of year. Thanks to canning, we can enjoy Italian marinara sauce on Monday and sauerkraut on hot dogs for lunch on Tuesday. Did our ancestors have any idea we would enjoy these canned foods hundreds and sometimes thousands of years later?

I first learned about canning from one of mentors, Chef Jessica Winchell. We would bring in vats of tomatoes from her garden and can them for the year. I remember it vividly. It was always in the heat of summer, so it was hot and muggy. The boiling from the canner exaggerated the heat in the kitchen. But I wouldn’t trade it for the world because it was a learning experience and knowledge is wisdom. As she taught me about canning methods, I learned to respect the seasons and the hard work that goes into growing tomatoes. It instilled in me the pursuit to create refined dishes using the humblest of ingredients.

As a chef, it’s easy to open a can of tomatoes. But it takes skill and wisdom to undertake the canning process. Now, with that said, canning might seem difficult your first time doing it. I’m here to tell you, if our ancestors could do it without fancy equipment then so can you. There are just a few guidelines you will need to follow in order to enjoy your favorite ingredients all year round.

One of the first things I learned to can was tomatoes under the mentorship of Jessica Winchell

Types of Canning Methods & Canners

There are three tried-and-tested methods for safely canning food at home. They are pressure canning, water bath canning and atmospheric steam canning. It is important to choose the correct canning method and canner for the food you are preserving to ensure that it’s safe to eat and high quality.

Home canning methods work by heating food in sealed jars until it is hot enough to destroy spoilage organisms. Applying heat forces air to be vented from the jar to create an airtight vacuum seal. To make canned foods safe for consumption, you will need to choose a canning method that will destroy all harmful bacteria and prevent their growth during storage.

Pressure Canners

A pressure canner is a sealed unit that builds up pressure as the temperature increases. Pressure canning is a must for processing low-acid vegetables and meats. Most vegetables fall into this category unless you are canning acidified tomatoes, pickles or sauerkraut.

Low-acid foods can support the growth of botulism, which can survive at the boiling point of water. Pressure canners prevent botulism by heating the water above 212F degrees (or 240F degrees at sea level).

There are two kinds of pressure canners. A weighted gauge pressure canner reaches 212F degrees and 10 pounds of pressure. A dial gauge pressure canner reaches 240F degrees and 11 pounds of pressure, which is adequate to destroy botulism spore at sea level.

This sounds technical, but all you need to know is that you’re pressure cooking the jars based on your manufacturer’s directions whether you’re using a dial gauge or weighted gauge, so don’t get too caught up in the details.

Types of Pressure Canners

Dial Gauge

A dial gauge pressure canner has a dial that indicates the pressure inside. As heat and pressure increase, the dial rises. Some dial gauges use 1/2 or 1-lb. increments. Others use 5 lb. increments, leaving the user to determine the pounds in between.

A dial gauge allows you to determine pressure increments for higher altitudes. At altitudes of 2,000 feet or less, the pressure should be 11 lbs. for meats and vegetables and 6 lbs. for fruits. You will need to monitor the gauge and adjust the heat to maintain the correct pressure.

Weighted Gauge

A weighted gauge pressure canner uses weights to control the pressure. One type of weight is a flat disk with 5, 10 and 15-lb. markings. Another type consists of three metal rings that sit on top of each other. For five pounds, only one ring is used. Each additional ring adds five more pounds.

When the canner reaches the desired pressure, the weight “jiggle” to indicate the proper temperature inside. Some weights jiggle three or four times a minute; Others jiggle continuously. It’s best to check the manufacturer’s directions for the canner you are using. Since you will be able to hear the jiggles, you can monitor the pressure without having to constantly keep an eye on the canner.

Weighted gauge pressure canners process meats and vegetables at 10 lbs. of pressure and fruits at 5 lbs. of pressure. At altitudes above 1,000 feet, it is necessary to increase the pressure by five pounds. Weighted gauge canners are reliable and do not need to be tested for accuracy.

Boiling Water Canners

Fruits, acidified tomatoes, pickled products, jams and jellies can be safely processed in a boiling water bath. A water bath canner works by submerging the jars in boiling water. The heat from the water transfers to the food inside the jars and creates an airtight seal for safe consumption.

The jars need to be surrounded by the boiling water including the top, bottom and sides. You will need a rack to allow the water to circulate under the jars. There also needs to be enough space in the canner so you can cover the top of the jars with one to two inches of water. It’s important that the canner has a lid.

Don’t have a boiling water canner? No problem. You can purchase one, or you can create a water bath canner from equipment you already own. You will need a pot that is deep enough so there is space for a rack, the jars, at least one to two inches of water above the jars and extra room for the water to boil rapidly without boiling over. Many newer canners are designed for processing jams and jellies so they are only deep enough for pint jars.

Atmospheric Steam Canners

Atmospheric steam canning is the latest method approved for home food preservation. It’s also the rarest method. Research from the University of Wisconsin shows the steam in an atmospheric steam canner reaches the temperature of boiling water (212F degrees) and is therefore safe for processing high-acid foods.

Atmospheric steam canners usually have a low base with a rack and a tall lid that fits over the jars. The lid has one or two holes that allows steam to escape. The lids needs to be left in place when the canner is heated to force air out of the canner until a column of steam forms that is six to eight inches long. This creates the atmosphere you will need to make canned items.

It’s similar to the boiling water method, just without all the water. The same foods that can be processed in boiling water can be safely processed in an atmospheric steam canner. Processing times are the same.

Farm2ChefsTable Tip: Foods that require processing for longer than 45 minutes should not be processed in an atmospheric steam canner because the canner could boil dry.