Harvesting your garden is also a great kid's activity. Kids love digging potatoes, harvesting popcorn, and pulling carrots. There is also a ton of science involved in food preservation, including concepts like: pressure, vacuums, bacteria, decomposition, life cycles, etc. There are so many ways to make this type of work a fun, learning experience for you, your students or children.
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Tomatoes on the window seat, tomatoes on the counter, tomatoes in the freezer and tomatoes on the vine. I would love to make some pasta sauce with those beautiful Romas and San Marzanos, dice up the Costolutos and put them in jars. I would even like to roast some cherry tomatoes and pop them in the freezer for a mid-winter treat. I know what you are thinking, "Well then, less talk, more action!". Alas, you need a critical amount of tomatoes of each type before you begin to can, blanch, freeze or dry and they don't all ripen at once.
Microorganisms, such as bacteria, are ready to do their part in the decomposition portion of your plant's life cycle. The plant grew your produce as a way of disseminating its own seeds, not as a kind gesture or repayment for watering it all summer. Once it has grown its fruit, eventually it will spoil. Bacteria are everywhere, and can be helpful or harmful to humans. Many of the bacteria you find in ripening and rotting veggies are not the helpful kind!
How Can You Preserve Your Harvest?
Drying or Dehydrating
Drying foods to preserve them was most likely another happy accident. The sun and wind are pretty good dehydrators. Most microbes that cause disease enjoy a moist environment to multiply in. When food is dried out it becomes an inhospitable place for those types of bacteria. You can dry produce in your oven or in an electric food dehydrator. Check out the Colorado State University Extension page for more information on drying and dehydrating your own vegetables. Electric food dehydrators can also be purchased fairly inexpensively.
Blanching and Freezing
Freezing veggies is a quick and fairly easy option to preserve them for later use. Before you freeze vegetables you should blanch them. Blanching is a process in which you heat the vegetables for a short period of time in boiling water. They are then removed and placed in an ice bath to stop the cooking process.
Blanching breaks down the enzymes that are at work ripening your food. The boiling action also helps to kill any microorganisms on the food. The blanched vegetables can then be placed in freezer bags or containers and frozen for longer periods of time. Different vegetables have different blanch times. See this link for the appropriate times for different types of produce.
Although a little more labor intensive, canning is one of my favorite ways to preserve food. If you follow a recipe and work carefully then the result is safe, well preserved food that looks awfully pretty in a jar, too. I use a heat bath canner. Basically this means that after your jars are packed you boil them for a certain amount of time to destroy any harmful microorganisms and to vacuum seal your jar shut.
Recipes for canning fruits and veggies will help you to determine if you need to add anything acidic to the jars to help preserve the food. Lemon juice and citric acid are common natural additives to preserving food canned at home. Microorganisms cannot tolerate acidic environments. I will be chronicling the process of canning my tomato sauce for you in a future post- stay tuned. For some great tips and recipes for canning, you should visit the Pick Your Own site.
For tried and true canning recipes, I recommend Ball Complete Book of Home Preserving
I'm excited this year to have produced enough tomatoes to make some sauce and can it for the winter. Slowly but surely, the tomatoes are ripening (I need 10 lbs of them). We're almost there, just some more patience. Then someday soon the tomatoes will be ripe and they will no longer wait. Time for that intense action I spoke of earlier. I will begin the job of blanching and peeling and cranking the food mill. I'll slowly simmer the sauce and then pack it into jars and put them in a hot water bath. It will be hours of work, but well worth the effort, the patience and time.
More on the science behind food preservation:
- Education.com- Food Preservation Science Fair Project
- How Stuff Works- Food Preservation
- University of Minnesota Extension- The Science of Freezing Foods