How to Freeze Summer Fruits and Vegetables
If you're getting overrun by fruits and veggies from your garden or CSA (or if you just want to take advantage of current sales), one of the best ways to put them up is to freeze them.
Different fruits and vegetables do best with different freezing techniques. Here's the best ways to freeze some common produce that's in season in Minnesota right now.
These are all fruits and vegetables that have recently appeared in Mankato's Dela Blu CSA and at the Mankato Farmers' Market. Look for freezing instructions for more varieties as the season progresses.
Berries
Strawberries, blueberries and other berries freeze beautifully with very little effort. Wash, stem and dry the berries. Spread in one layer on cookie sheets and freeze for an hour or two to "flash freeze." This will enable the berries to freeze on their own and prevent solid clumps of berries. Then scoop the berries into freezer bags or glass jars.
Rhubarb
Remove leaves, wash and slice into half inch pieces. Flash freeze as above and store in bags or jars.
Peas (in the pod) and green beans
Wash and trim ends or shell, then blanch. Blanching inactivates enzymes that lead to changes in color, taste, texture and nutrition. To blanch green beans, plunge them in boiling water for 3 1/2 minutes (a collander or immersion basket can make this easier) and then plunge them into ice water. For peas in the pod, blanch for 2 1/2 minutes (shelled peas require only 1 1/2). Cool, drain and dry, and then flash freeze and proceed as above.
Spinach and swiss chard leaves
Wash, trim tough stems and coarsely chop. Blanch for two minutes, drain and proceed as above. If you plan to use the leaves for green smoothies, you can reduce the blanching time to one minute or simply flash freeze and store as above.
Swiss chard stems
Few people realize that chard stems can also be used for cooking. These are great in soups, stews and stir fries. Prepare them separately from the leaves and chop in one inch pieces. Blanch for three minutes, flash freeze and put in freezer bags or jars.
Broccoli
Wash and chop into large pieces. Peel tough stems before slicing. Blanch for four minutes, flash freeze and then freeze in preferred containers.
Zucchini
There are two common ways to freeze zucchini, depending on how you plan to use it. You can slice zucchini into 1/2 inch pieces and blanch it, then proceed as above. Note that it will be somewhat soggy if done this way. You can also shred zucchini, squeeze out extra moisture and freeze in one cup portions for adding to quick breads, sauces and such. It is possible to steam blanch the shredded zucchini to preserve the most nutrients (just put it in a steamer basket over a pot, steam for a couple of minutes and proceed as normal).
Squash
First, assemble the items needed : a pan of boiling water, a bowl of ice water, washed summer squash diced (do this right before so the veggies stay fresh and colorful) and freezer bags. Bring the pan of water to a boil. This is going to stop the enzymes from causing the squash to decay, lose color and texture, and most of all, to preserve the nutrients. Place the diced squash in the boiling water, for about 3 minutes. Remove the squash with a slotted spoon and immediately place into the bowl of ice water. This will stop the cooking action and preserve flavor. After it cools, remove from cold water. Place in freezer bags. Choose the size that will best work with your style of cooking, small pint bags, larger quart bags or big gallon bags.
Carrots
Wash, peel and trim carrots. You can slice large carrots into thin slices or leave small carrots whole. Blanch slices for 3 1/2 minutes and whole carrots for five. Proceed as above with flash freezing and storage.
Kohlrabi
Remove tops, wash, peel and cut into 1/2" cubes. Blanch for 2 1/2 minutes and procceed as usual.
Be sure to label your containers with the contents and the date. Use within 6 months or so.
The University of Minnesota extension office offers more information on freezing fruits and vegetables here.