home food preservation

Keep Your Food Safe & Fresh: Simple Canning & Preservation Tips

Are you looking for a way to keep fruits and vegetables fresh for longer? Do you want to extend the shelf life of summer and fall foods from your garden?  The webinar hosted in late September is now available for viewing online! Follow the link below to the webinar recording, and follow along with the slides provided below.  While there is a lot of technical information in the webinar, a cooking demo begins at minute 35 of the video.


Loader Loading...
EAD Logo Taking too long?

Reload Reload document
| Open Open in new tab


Getting Ready for Home Preservation Season

By Diane Wright Hirsch, MPH

Senior Extension Educator/Food Safety

As the end of June looms, back yard gardeners and farmers alike are beginning to see the fruits (and vegetables) of their labor. Already we are enjoying locally grown spinach, lettuces, herbs and other greens, peas, and perhaps locally grown broccoli and cabbage. Asparagus season is over, and strawberries, thanks to a later season, may be around for a few more weeks. But as we go through July, we can look forward to blueberries, summer raspberries, green beans, beets, cucumbers, peppers, and the holy grail of fresh sweet corn and field tomatoes. So far the growing season has been blessed with sufficient rain and good weather, crops are happy and will likely be very productive.

So, now is the time to begin preparations for safe home food preservation, whether you have a garden or a favorite farm or farmers’ market.

First, determine what method of home food preservation works best for you. Your choice may depend on your preference for the resulting product (frozen vs canned green beans, for example, are very different in taste and texture); your storage space; the tools or resources you have at your disposal (Canner? Pressure canner? Separate deep freezer? Refrigerator freezer only?); and, perhaps, the cost of the process. Since most folks think that preserving at home will save them money, a recent article from the University of Maine, The Cost of Preserving Food in Maine (https://extension.umaine.edu/publications/4032e/ ), might make a good read.

They looked only at the costs of energy (in Maine) and equipment used to preserve food as the cost of the food itself varies depending on where it is purchased. When freezing, the most expensive part of the equation is the freezer itself. After that, they factored in the cost of energy and the container, which in this case was a reusable container. One time use containers and freezer bags will add to costs. Freezing was estimated at 38 cents per pound of food.

The cost of pressure canning is $1.14 per pound, while using a water bath canner will cost approximately 73 cents per pound. The difference here is the cost of the canner. A pressure canner is over three times the cost of a water bath canning pot when amortized over 20 years. (Using these figures and assuming the cost of a pound of fresh tomatoes is $3.50, and 91% of the pound is useable, the cost of a pound of home canned tomatoes is approximately $3.92. The cost of a pound of commercially canned tomatoes is about 92 cents.*)

Finally, dehydration is a rather costly operation in this part of the world at 99 cents per pound. You must use an electric dehydrator to be successful as the climate (some heat, more humidity) will not allow us to use the sun alone.

The differences may not seem significant unless you are putting away large quantities of food. I had always thought that freezing was the most expensive option. Not according to this study. The efficiency of modern freezers has probably changed this.

Once you decide which method you will use, then start gathering your supplies. As someone who likes to procrastinate, local sources can get depleted over the course of the summer season. Online sources are more reliable as it gets closer to September.

If freezing:

  • If you need to purchase a freezer, keep in mind that a full freezer is more efficient. Buy only the space you need, do not overbuy. An upright is less efficient than a chest freezer, but I find it very easy to lose things in a deep chest freezer!
  • If you own a freezer, eat what you can out of your freezer to make room for the new crop.
  • Stock up on containers. Reusable are best. Make sure they are appropriate for the freezer. Some plastics will crack when frozen. Rigid containers stack more easily. If using freezer bags, again, make sure they are freezer and not simply food storage bags.
  • A permanent marker and freezer tape or labels are essential as well.

If canning:

  • Purchase a new or check the condition of your water bath canner. The water bath canner or large pot should be clean, have a lid, and a rack to hold the jars off the bottom. Be sure you can locate all the pieces and replace what might be missing.
  • Purchase a new pressure canner or, if you already own one, keep in mind that a pressure canner with a dial gauge needs to be tested yearly. Have that done now. We do pressure gauge testing here at the office (hirsch@uconn.edu) or call 203.407.3163. If you cannot make it here, you can send gauges to your canner manufacturer to be tested. That will take some time, so get it done as soon as possible. Be sure to check your gasket and other rubber parts to make sure they are not dried out or cracked. If they are, replace them. Make sure there is a rack to keep jars off the bottom of the canner.
  • Check your supply of jars, lids and rings. The sealing compounds on lids can dry up and crack. Check the date on the box. If older than two or three years, it would be best to buy new. If jar rings are rusty, you should replace them. Check your jars. If the rims are chipped or cracked, replace with new. A chipped rim will prevent a good seal from forming.
  • Find or replace your other tools: timers, spatulas, jar lifters, ladles, funnels, etc.

If dehydrating:

  • Purchase or check on your dehydrator to make sure that it is working and that you have sufficient racks or screens.
  • Purchase your storage equipment, whether it is freezer bags, canning jars or other air tight, food-safe containers.

Of course, when you get ready to can, freeze or dehydrate, be sure to make sure all of your equipment is cleaned with detergent and hot water prior to using. Follow instructions for preparing canning jars and lids.

Last, but not least, update your information regarding safe home food preservation. Check with the National Center for Home Food Preservation http://nchfp.uga.edu/. In addition to safe processing methods, they also have a blog that provides timely information and advice: https://preservingfoodathome.com/. The Ball Blue Book, generally recognized by Extension food safety professionals as safe, is updated regularly.

*Based on figures from USDA/ERS Fruit and Vegetable Prices, 2015

For more information on home food preservation, go to foodsafety.uconn.edu.

Jam 101

By Diane Wright Hirsch, UConn Extension Educator, Food Safety

Photo: Clemson Extension


clemson jamOne of the best things about June in Connecticut is strawberry season. And we have been waiting a long time for strawberry season this year in Connecticut!  Most farmers will tell you that the cold spring and delayed picking as much as 2-3 weeks.  Even now, the supply is still gearing up.  Get to your farmers’ market early in the day if you want to score a box or two.  And be sure to check with your favorite pick-your-own (PYO) operation.  Some are just starting up this week.


Pick berries that are bright red and leave the overripe, mushy or those that are obviously headed in the wrong direction.  If you are planning to make jam or jelly, don’t think that you can get by with shoddy, overripe berries—you might end up with shoddy, over-mushy jam. A good rule to follow when it comes to preserving food at home—whether it is canned tomatoes, frozen green beans or strawberry jam:  you will never end up with a product that is of better quality than the produce (tomatoes, green beans, strawberries) that you started out with.


Refrigerate the berries as soon as you can after picking. Store unwashed berries loosely covered with plastic wrap in the coldest part of your refrigerator for two to three days at most. But, do not wash the berries before refrigerating them.  If washed, the berries are more likely to get moldy in your refrigerator.  Always wash them before eating, though. To wash, place berries in a colander and rinse under cold running water. Do not allow berries to soak in water—they will lose color, flavor and vitamin C.

Jam 101

If you plan to make strawberry jam, be sure you are following the most up to date guidelines.  Jam is made from crushed or chopped fruits and sugar. All jellied fruit products, jams, jellies, preserves, need to have just the right combination of fruit, pectin, acid and sugar in order to actually be “jellied.” 


Pectins are the substances in fruits that form a gel if they are in the right combination with acid and sugar. While all fruits contain some pectin, some have enough to form a gel on their own, while others, including strawberries, contain little pectin and the cook must use some commercial pectin in order to make a true jam or jelly. Because fully ripened fruit has less pectin, one-fourth of the fruit used in making jellies without added pectin should be underripe. That is why overripe fruit do not make good jams or jellies, they have less pectin and may result in a runny, under-gelled product.


The proper level of acidity is critical to gel formation. If there is too little acid, the gel will never set; if there is too much acid, the gel will lose liquid (weep).  Again, an underripe fruit may have less acid, preventing the gel from forming.  Commercial pectin products contain acids which help to ensure gelling.


Finally, there is the demon SUGAR.  Sugar serves as a preserving agent, contributes flavor, and aids in gelling. Many home cooks ruin a perfectly good product when they try to cut down on the sugar in a jam recipe.  Don’t do it! Too little sugar prevents gelling and may allow yeasts and molds to grow. Commercial low-sugar products are likely to use a different type of pectin (also available to the home cook) or sugar substitutes.  But really, how much jam do you eat?  It would be better to drink less soda, fewer candy bars, cookies or other commercially sweetened products and save your sugar calories for some home-made jams.


As a kid I remember the paraffin covered jams my mom used to make…and I also remember scraping the mold off of many of them.  But, research now shows that the mold we scraped off the surface of those jams and jellies may not be as harmless as it seems. Mycotoxins (or, mold toxins)  have been found in some jars of jelly having surface mold growth. Mycotoxins are known to cause cancer in animals; their effects on humans are still being researched.


Because of possible mold contamination, paraffin or wax seals are no longer recommended.  It is best to fill sterile jam or jelly style canning jars, leaving 1/4-inch headspace, seal with self-sealing lids, and process 5 minutes in a boiling-water canner. This little bit of extra work (actually, I think the whole paraffin thing was messier and more time consuming) will mean less chance of having to throw out the fruits of your labor.


For more information about safe handling of fresh-picked strawberries, contact the UConn Home and Garden Education Center at 877-486-6271 or the National Center for Home Food Preservationfor canning and freezing information.