Category Archives: Canning

Dry Canning Raw Vegetables is an Unsafe Practice

Some people are experimenting with canning fresh vegetables their own way instead of following research-based processing from USDA. The USDA home canning procedure is meant to kill spores of Clostridium botulinum, the bacteria that cause the potentially deadly botulism poisoning.  The latest version of people making up their own method that is potentially very hazardous has been brought to our attention through emails and calls to the USDA Hotline. It involves putting raw vegetables (such as corn, green beans, carrots, beets or other vegetables) in canning jars with no added liquid, applying lids and pressure canning for the same amount of time as if you had added the water to cover required in the USDA method.

What is hazardous about this “dry canning” of vegetables?

  • In the pressure processes we have to recommend for home canning of vegetable, the liquid covering pieces of vegetables in the jars is required for the expected heat penetration throughout the jars during processing. The food must be prepared and jars filled just as described for the USDA process time to work as expected in killing bacteria of concern.
  • It is well known that bacteria and bacterial spores are more sensitive to wet heat than dry heat. They will die in hot dry air much slowly than in hot water. So, if the process was researched with water or other liquid in the jars, it is not expected that the same process time will be long enough heating for a jar without the liquid in it.
  • The risk here is botulism, which is a food poisoning disease that can be fatal (or kill people).  Botulism toxin can be present in canned vegetables without any visual changes to the food or odors.  Please read what the Centers for Disease Control and Prevention (CDC) has to say about botulism and home canning, and particularly note the section on here called What is Botulism:

Sliced carrots in home canning jar without water and a red X with saying "needs water over carrots to process"Home canned carrots in jars with water covering the carrots









But people say it works and like the food…

  • Someone can get lucky and not get sick from trying this. Bacteria are not distributed evenly throughout our environment. But the next time, Clostridium botulinum or other harmful bacteria can be in the jar and botulism poisoning could result.
  • And by the way, some people who have made up this method on their own are adding butter or ghee even if no water. These are no substitute for the required liquid in the jars, either. And these should not be added to the jars even with liquid in research-based processes if not called for in the original instructions.

Home canning and creativity

  • Canning preservation of food is not a creative activity about how to produce the best quality only. Safety must come first, and the researched processes we have for vegetables require the liquid cover in the jars (and whatever is the type of liquid called for in the described procedure with each process, which is usually water for plain vegetables).​
  • Again, the USDA low-acid home canning recommended processes are meant to be used with the full procedures as written — how to select and prepare the food, how to fill jars, how to manage the step by step canning process in a recommended pressure canner type, and how to make altitude adjustments.

Be food-safe when home canning, please, and stay with properly researched and tested procedures.

Recommended procedures for home canning of vegetables: and read about safe canning here: and


Bowl with whole raw peaches

Peach Season Has Arrived

Peach picking time is here!  The first crop of the year is arriving at roadside fruit stands, farm markets, and grocery stores. The weather seems to have cooperated with perfect temperatures, enough rain, and ample sunshine to ensure a winning season. Preserving peaches by canning, freezing, or drying is the best way to extend the use of this popular fruit long after the harvest is over.

Select well-ripened peaches and handle carefully to avoid bruising. Use safe food handling practices before, during, and after preserving the fruit.  Wash hands with soap and water. Wash all surfaces and utensils with soap and hot water, rinse, and air dry.    Wash peaches by gently rubbing under cold running water, drain, and blot dry with paper toweling.  If peaches are not used immediately, refrigerate at 40 degrees F or below until ready to preserve.

Raw peach cut with several slices next to it

To prevent peaches from darkening, peeled and then cut fruit can be placed in ascorbic acid solution.  To peel easily, dip peaches in boiling water for 30 to 60 seconds until skins loosen. Then dip quickly in cold water and slip off skins.


Canning Peaches

Prepare for canning yellow peaches by first reviewing how to use a boiling water canner or pressure canner.  Traditional yellow peach varieties can be processed by both methods in either halves or slices. Yellow peaches can be packed in water, apple juice, or white grape juice for canning or a very light, light or medium sugar syrup.  Hot packs are recommended for best quality.

Canning white-flesh peaches is not recommended. The natural pH of white peaches can exceed 4.6 making them a low-acid food for canning purposes.  Currently there is no low-acid pressure process available for white flesh peaches nor a researched acidification procedure for safe boiling water canning.  Freezing is the recommended method of preserving white-flesh peaches.

Freezing Peaches

Freezing peaches is easy, convenient, and less-time consuming than canning.  Choose a sugar syrup, dry sugar, or unsweetened pack with halved, sliced, crushed, or puréed peaches.  When ready to eat, sliced or halved peaches are best served partially thawed so that textural changes are not as noticeable from the effect of freezing on fruit tissue.

Sweet Peach Spreads and Condiments

Sweet spreads and syrups are a favorite way to preserve peaches.  Jelled or thickened peach products include jellies, jams, preserves, conserves, and marmalades; most are preserved partially by their sugar content.  Other products that are partially preserved by a high sugar content but not jellied include peach butter and peach honey.  USDA recommendations include a reduced sugar peach-pineapple spread that can be made without adding sugar or optionally adding less sugar and canning it for room temperature storage.  (It can also be frozen for storage.)  Reduced sugar or no-sugar-added jam takes purchasing a special commercial pectin modified to gel with a reduced sugar content.

The National Center for Home Food Preservation website has some other offerings for home canned specialties that use peaches, such as peach salsa, chutney, several relishes, and pickled peaches.

Take advantage of the season to preserve some peaches for use throughout the year.


Canning Dry Beans: It Matters How They Go in the Jar

As a low-acid food, all beans require the use of a pressure canner for preservation by home canning, unless they are sufficiently pickled (acidified) to bring them out of the low-acid food category. But pressure canning isn’t a magic bullet if you don’t know the safe way to prepare food and carry out the right process for each food type and style. If you are new to pressure canning or could use a refresher of the basic how-to, then please read Using Pressure Canners before beginning. If this is your first time canning, then also read Principles of Home Canning from the USDA Complete Guide to Home Canning. 

Recommended procedure for home canning of dry beans

The USDA recommended process in the Complete Guide to Home Canning for home canning dried beans require a hydration step prior to filling jars:

The options are to (1) place sorted (for stones or other contaminants) dried beans or peas in a large pot and cover with water. Soak the beans 12 to 18 hours in a cool place. Then drain off the soaking water and do not use it in canning the beans. The other option is, to more quickly hydrate the beans (2) cover the sorted and washed beans with boiling water in a saucepan. Boil them 2 minutes, remove them from the heat, soak them 1 hour and then drain. That cooking water is also not used in canning the beans.

The procedure then calls for covering drained beans hydrated by either method with fresh water and boil 30 minutes. The USDA canning process recommendation is for a hot pack prepared this way only: hot beans boiled 30 minutes then filled quickly into jars while still hot. (But of course being careful not to burn yourself, as with all canning steps.) Optional salt can be added to the beans in the jars if desired (½ teaspoon of salt per pint or 1 teaspoon per quart jar). The jars with cooked beans (and salt if added) then get filled with the hot cooking water, leaving 1-inch headspace. As with all jars packed this way, water should cover the food pieces for expected heat distribution during processing and best quality in storage of the canned beans.  See the link above for full instructions and the processing times and temperatures (pressures) for pints vs quarts, and for various altitudes.

Do not put dry beans directly into the jar

According to inquiries I get, and what I read elsewhere on the Internet, it is popular practice to put dry beans in the jars, cover them with water and put them into the pressure canner that way. Unfortunately, I have never found or been shown research for home canning that has determined what the process time should be for dry beans filled into jars in this manner.  A safe process time is partially dependent on jar size and type of food, yes, but it is also partially dependent on the texture of the food, the temperature of the food and liquid, and the weight of the food filled into jars.  Dry beans sitting in water at the start of the process time will not heat up at the same rate as beans prepared as described in the research-based method described above and in the USDA materials. The final sterilization of the jar contents achieved by the end of the process will not be the same as when the process is applied to jars filled as described in the recommended methods.  People canning their dry beans by other methods, and especially by starting with dry beans in the jars, are taking a big risk on food spoilage and possibly botulism food poisoning.  Those doing this and getting away with it have just been lucky – so far. If you choose to do it, you are taking a chance by your own decision.

Additional home canning options for dry beans

There are also different processes for different types of beans and dry bean recipes for home canning. For canning dry beans, there are research-based processes in the USDA database for Baked Beans, prepared as described in the process directions, and Dry Beans with Tomato or Molasses Sauce versions provided.

Home canning of fresh beans

If you have fresh beans of the Lima variety, then follow these directions for Fresh, Shelled, Lima Beans. Follow these similar procedures, but slightly different directions for Snap and Italian Green and Wax Beans. As you’re deciding whether to prepare a hot pack or raw pack, remember that hot packs are often considered to produce the highest quality final product, and you can often fit more beans into one jar, even though raw packs do cut down on the prep time.

The home canning processes which we can recommend for these various bean products can be found at the National Center for Home Food Preservation website at this menu: .

Be safe when canning and use research-based processes for all your beans

Please be safe in your home canning choices. The research-based processes available may seem very limiting and traditional but there has been little public funding for researching new recommendations in a long time and there are few labs set up and staffed to do home canning research. You can flavor or combine your home canned vegetables with other ingredients after opening them, at the time of serving, rather than risk botulism or losing money from spoiled food from making up a process for your own recipes. This solution doesn’t address choosing an easier way to fill jars than has been tested such as with dry beans, but is something to consider for other food choices.

Even though this has been about dry beans, I hope you all are looking forward to another season of local, fresh vegetables coming in like I am!


Dry grains and beans in canning jars

“Dry Canning” Isn’t Canning To Me

Quite a few people are circulating directions for what they call “dry canning” as a method of storing dried foods. It is not a food preservation method we recommend.

What is canning?

Just because canning jars are used in “dry canning” does not mean the suggested procedures fit the classic definition of canning.

Canning as a method of food preservation or processing refers to a procedure of heat treating closed containers of food with the goal of producing what is called a “commercially sterile”, vacuum sealed-food that can then be stored safely at room temperature. The preservation goal is to kill any spoilage and pathogenic (harmful) microorganisms that otherwise would be able to survive in food at room temperature storage. In some categories of foods, bacteria can also be controlled by acidity or moisture control as well as the heat of canning. In other foods (e.g., low-acid or slightly acid foods) heat usually has to do the whole job. Different foods will have different microorganisms targeted for killing or control, depending on the nature of the food.

Why dry canning isn’t canning

Canning is done with moist foods because the moisture inside the container would support the growth of microorganisms. Dried foods do not have the same concerns even if a food is low-acid because the removal of available moisture limits or prevents the growth of microorganisms. Storage of dried foods for long periods of time will take into consideration means to preserve food quality, however, as well as preventing reabsorption of moisture into the food.

“Dry canning” techniques I see circulating call for putting dried food like grains, beans, and nuts, into canning jars. In some methods, canning lids are then placed on the jars and the jars heated in an oven. Usually about 200°F is recommended. In other directions, the food in jars is heated without the lids, which are then placed on the jars when they come out of the oven.

These procedures do not describe true canning preservation of food but instead would be considered a method of packaging dried foods for storage — one that, again, we cannot recommend because of several issues with it.

Issues with dry canning

Here are some issues to think about with this concept:

  1. This process is not “canning” just because it uses canning jars.
  2. It is unknown if this process can sterilize the food, although it might cause vacuum sealing of jars. This would not be a time and temperature combination known to kill many bacterial spores or mold spores.
  3. This method does not remove all of the oxygen from the jar before sealing and may trap moisture from the food if condensation occurs. While the presence of spores would not be an issue in very dry foods, any moisture pockets say from condensation or incompletely dried foods could be a problem. Moisture in the jar with some retained oxygen could support the growth of airborne molds or even bacteria not killed by the low heating in some seemingly dry foods. Some foods may seem dry to the consumer but still have enough moisture in them to come out upon heating and closing up in a container. This could be especially true of home dried foods.
  4. The dry oven process used at home has never been shown to sterilize these various dry foods or produce the claimed extended shelf life with quality. In fact, there is no known researched shelf life for foods packaged just this way at home.  (If someone can lead me to the research I have not been able to find, please let me know.) Extended shelf life expectations are available for dry foods prepared and packaged by other methods (see the Utah State University Extension references below).
  5. This heating could even make the quality of some foods worse.  This could be either by moisture condensation upon cooling, or if the food is lipid-containing nuts and grains, increased enzymatic reaction causing rancidity.
  6. A major manufacturer of canning jars and lids in the U.S. does not support the use of their jars and lids/sealing compound in this manner.
  7. Because this type of process is not recommended, doing it can be a waste of resources, time and energy.

Recommended storage methods for dry goods


Photo by E. Andress


Thoroughly dried foods can be stored a fairly long time in airtight containers at moderate room temperatures or in the freezer. If you want to vacuum seal containers of dry foods, methods that will preserve them safely and provide better food quality include:

(1) A vacuum sealing machine that has adapters for jars in addition to sealing bags if you want your food in jars.  This vacuum packaging is done at room temperature without heating the food.

(2) Oxygen absorbers inside your containers of these foods.  Oxygen absorbers can help preserve the quality of foods and also aid in insect control.

(3) If you are using the heating method to control for possible insect contamination of your dried food, the Utah State University booklet linked below has methods for heating and then cooling dry foods BEFORE they are packaged for storage. It also describes freezing procedures before packaging as an alternative to insect control. Even heating some foods on an open oven tray before packaging can cause some flavor changes that using the freezing method would not.

Utah State University Extension methods, for example, for long-term storage of dry rice and beans:

10-year storage of rice:

10 or more years for beans:

And here is a large book/booklet from Utah State University about storing food, A Guide to Food Storage for Emergencies, with more specific information and the oven or freezing methods for insect control:

I would like to thank my colleagues in some other states for helping to review and contribute to these points. Nancy Flores at New Mexico State University helped get some organization and formatting to them, and Karen Blakeslee at Kansas State University helped with review and additions.  There were others who initially reviewed my first version and I thank them also.