Community Garden
Canning and Freezing
Canning and Freezing Your Produce
Learning how to preserve fresh produce is a rewarding way to capture the flavor of the season and reduce food waste. This page explores canning versus freezing, helping you understand the benefits of each method and choose the best option for preserving fruits and vegetables from your garden or local harvest.
Why preserve food at home?
- Eat local
- Know what is in your food
- Reduce waste
- Make what you cannot find in the grocery store
- Share your bounty
- Preserve tradition
- Save money
Canning Details
Grab Your Supplies!
Canning: What you will need
- Water-bath canner
- Canning jars with two-part lids
- Canning funnel
- Long-handled spoon/ladle and slotted spoon
- Jar-lifting tongs
- Pots, bowls, measuring cups
- Plastic/wooden tool
Choose your canning method
The canning method that is approved for a food depends on the type of food. Foods are divided into two main categories:
Acid Foods
- pH of 4.6 or lower
- generally all fruits
- tomatoes and figs are borderline (specific amounts of citric acid or lemon juice must be added before canning to acidify)
- sauerkraut
- Foods to which large amounts of acids are added (pickles)
Low Acid Foods
- pH greater than 4.6
- generally all vegetables
- meats, poultry, seafood
- soups
- mixtures of acid and low acid foods (pasta sauce with meat and/or vegetables)
Botulism
Low-acid foods must be pressure canned to prevent clostridium botulism from forming.
- Follow all directions from a reputable source (USDA, University of Minnesota Extension, Ball Blue Book, etc.)
- Follow processing times exactly and adjust for altitude when necessary.
- Up-to-date methods and information should be used.
No oxygen + moisture + warmth = Botulism
Methods of packing
Raw Pack
- For foods that lose shape when cooked
- Place raw food directly in jars. Boiling hot liquid is then poured over the food.
- Pack firmly, do not crush.
- Add jars carefully to canner.
Hot Pack
- Preferred method for most foods.
- Food is cooked in liquid before packing. Cooking liquid is poured over food in jar.
- Fewer jars needed.
- Less floating.
- Better color and flavor.
- Easier to pack; food is pliable.
Headspace
Headspace is the space in the jar between the inside of the lid and the top of the food jar or its liquid. Check directions for correct headspace.
Typical headspace:
- One quarter inch for jellied fruit products
- One half inch for fruits, tomatoes, and pickles
- One to one and one quarter inch for low acid foods
Canning: Step by Step
7 steps for canning
Delight in the tastes of summer in the winter!
Step 1: Sterilize
- Wash all equipment and dry on clean surface.
- Use only canning jars with no nicks, cracks, or scratches.
- Boil the jars for at least 10 minutes.
- Heat the lids in simmering water.
Step 2: Prepare
- Prepare your fruits/vegetables according to the recipe.
- Food quality does not improve as it is processed, so start with the best quality possible.
Step 3: Pack
- Fill jars according to the recipe.
- Leave the proper and recommended headspace.
Step 4: Seal
- Remove air bubbles by stirring content with a plastic/wooden tool.
- Wipe the rim of the jar clean.
- Set the lid on jar rim and twist on the metal band until finger tight. Don't overtighten.
Step 5: Boil
- Fill the canner with at least 6 inches of water and bring to a boil.
- Place the jars in the rack and lower into the boiling water.
- Jars should be covered with at least 1-2 inches of water.
- Begin timing as instructed in the recipe once the water returns to a boil.
Step 6: Cool
- Remove jars from the rack and set on a clean towel, leaving a little space between.
- Listen for the "ping" or "pop."
- Lids should sink inward.
- Jars that have not "popped" did not seal properly. Attempt to reseal or refrigerate.
Step 7: Label
- Wipe all jars.
- Celery label and date.
- Note: Some suggest removing the rings.
Freezing Details
Foods that freeze well
- Asparagus
- Berries
- Broccoli
- Carrots
- Cauliflower
- Chard
- Collards
- Corn
- Eggplant
- Green beans
- Herbs
- Kale
- Kohlrabi
- Okra
- Peas
- Peppers
- Rhubarb
- Spinach
- Squash
- Tomatoes
Advantages of freezing
- Many foods can be frozen
- Retain color, flavor, and nutritional value
- Texture is often better than other preservation methods
- Food can be preserved more quickly than canning and drying
- Simple
- Convenient for food preparation later
Disadvantages of freezing
- Texture is not the same as fresh
- Investment in a freezer may not be an option.
- Storage in limited by the space in your freezer.
General freezing instructions
Selection of food
- Freezing does not improve quality
- Choose highest quality available
- Freeze promptly
- Not all food freeze well
Preparation
- Work in a clean environment
- Follow recommended procedures
Packaging Materials
Ensure your packaging materials meet the following criteria:
- Moisture resistant
- Durable and leak-proof
- Will not become brittle and crack at low temperatures
- Resistant to grease and oil
- Does not absorb or allow the absorption of flavors or odors
- Easy to seal and label
Recommended packaging:
- Plastic freezer containers
- Wide-mouth canning/freezing jars
- Food sealer bags
Freezing fruits and vegetables
- Freeze as soon as possible after harvesting
- Prepare food by cleaning and cutting if necessary
- Vegetables: Generally blanch before freezing to stop or slow enzyme action
- Fruit: freeze in individual layers on cookie sheet lined with parchment paper
- Store in air-tight packaging and allow for head space of liquids in rigid packaging
- Label