Canning Tips from Glenda Taylor

Read this and your recipe all the way through before you begin your process.  Timing and accuracy is essential, so it’s best to have everything ready ahead of time.

What happens in canning to preserve food;  why is it safe to eat canned food?

I can’t say this is exact science, but it’s how I understand the process:

During the canning process, described in detail below, a person fills a sterilized jar with food, leaving about 1 inch of empty space between the food inside the jar and the top of the jar.  Lids and rings are placed to close the jar, tightened only by hand.  Then the filled jars are heated in special ways, raising the temperature of the material inside the food-filled jar to a certain necessary temperature.  The jar of food is thus made safe from bacteria, and also something else important happens.  Everything inside the jar expands because of the intense heat.  This forces out gases and air, which escapes around the tiny gap between the lid and the jar, until a vacuum is created in the jar. When there is no more air in the jar with the sterilized food, there can be no more contamination of the product until more air is introduced.  When the lid is sealed, the food cam be preserved in a sterile condition until the lid is opened, at which point you must use the food immediately or refrigerate it and use soon.

Basic Equipment:

For Acid foods that can use Water Bath process (explained below):

Big pot with lid and rack in bottom, big enough to leave two or three inches of water over top of jar sitting on rack.  Any pot you have on hand will do, if big enough.  Since you are boiling water in it, it doesn’t have to be heavy duty.

Rack to fit the bottom of the pot.  If you don’t have a rack, you can tie screw bands together to make a rack that works fine.  A cake cooling rack also works, if  it is big enough.

Regular Canning jars (must be “mason” jars, brands vary, but don’t use leftover jars from products you bought full of food at the store; only regular canning jars will match the screw bands needed to can.)  Be sure there are no chips or cracks in the rims.  You can, of course, reuse the regular canning jars.  Often you can find them cheap at thrift stores much cheaper than buying them new.  I keep the boxes the new jars come in, to store the finished canned product in safely, or to store the emptied clean jars in after using the canned product.

 Regular Canning screw rings and lids.  Be sure the size matches the size of your jars.  Use new lids each time; rings can be reused.  Lids are specially made with food safe compound on the inside.  Rings are only necessary for the processing stage to seal the lid.  If you want to leave them on the jars afterward (I do), once the jars are sealed and cooled, remove the ring and dry it off; that way it won’t rust.  Only hand tighten rings before processing, and do not tighten again after processing, as this could break the seal.  After processing and cooling, lids may “ping” as they seal; after sealing, lids should be slightly concave in the center and not move when you touch them; this assures a good seal.

Jar lifter.  Specially made to lift hot jars out of boiling water.

Non-metallic thin straight spatula to insert in filled hot jars to get the air bubbles out.

Non-metallic funnel that fits in the top of the jar to aid in filling jars.

Cloth thick dish towel to set out on the counter top to set the hot jars out of the boiling water on; cool counter top or wooden board may be too drastic change in temperature and sudden drastic temperature change can cause the jar to break.  (Remember this, too, if inserting jars into very hot water in a cooker.)

 One cup glass liquid measuring cup.  Do not use larger measuring cups in measuring liquid ingredients in a recipe, as they are not as accurate, and in canning, especially jelled products, accuracy is more essential than in regular cooking.  Use the kind of measuring cup that is larger than one cup, with marks on the side, to be sure you can see that you have exactly one cup, or whatever the recipe calls for.

Flat edged measuring cups for non-liquid measuring.  You must level off the top of cup of a non-liquid ingredient with a flat-edged utensil (like a straight edged knife) to be sure you have the exact amount.  Same with measuring spoons.

Candy thermometer.  Not absolutely essential, but helpful when making jelly.

Cheesecloth.  Can be purchased at most kitchen stores.  Wash it and dry it before and after use each time.

Colander.  If you can find one of the old-fashioned cone shaped ones with a wooden pestle, perfect for making juice from grapes, berries, etc., buy me one!!!  My mom’s is gone, and I can’t find one.  But the regular ones are also useful for other things.  Have one of them be non-metalic.

Non-acid foods must use Pressure Cooker large enough to accommodate jar height with a bit of room to spare.

Depending on Recipe, you may need the following:

 Heavy stainless steel pot big enough to boil ingredients without boiling over.

Canning salt.  Use this instead of regular salt, as canning salt is different from regular salt.

Bottled Lemon juice.  Although this is the only time I ever use bottled lemon juice, it is very convenient when you need a tablespoon or two at a time, with no seeds or pulp.

Powdered or liquid fruit pectin. 

Pectin is something that occurs naturally in fruit that helps it jell in the cooking process.  However, the amount may vary depending on the fruit’s growing and storing and cooking circumstances.  Most fruits, except apples, concord grapes and crabapples, do not have enough pectin to make jelly.  Adding apple, grapes, or purchasing powdered or liquid pectin can assure a proper amount for your jellies.  Purchased pectin also reduces the amount of time that the fruit has to be boiled in order to jell, thus possibly preserving more nutrients (although old timers say that using pectin slightly reduces the flavor).  Liquid pectin requires the least amount of boiling time.  By adding apples or grapes or pectin to your recipes for jams and preserves, as well as jellies, you can extend the volume of finished product, since the fruit does not “boil away” in the cooking process required without added pectin.  (see paragraphs below for special directions for using purchased liquid or powdered pectin.) Slightly under-ripened fruit has more pectin than ripe fruit.  Sometimes adding a little under-ripened fruit can help the jelling process, but too much under-ripe fruit can make soft spreads tough.

However, it is not necessary to purchase the powered or liquid pectin to make jelly; our grandmothers certainly didn’t use it.  The flavor of the jelled product changes slightly if using purchased pectin or not using it.  Not using it requires you to boil the fruit longer, and thus the finished product is more concentrated.  Using purchased pectin may result in a product that tastes fresher because processed for a shorter time, and it makes more jelly with less fruit, but long-boiled fruit without added pectin produces a flavor more concentrated, and may be more to your liking. It’s up to you.  Try it both ways.

Also, adding other high-pectin fruits (like apples) to a recipe can not only increase the amount of natural pectin, it adds natural sweetness. This is especially helpful if you if you are trying to make a lower-sugar product.  Also, purchased pectin especially designed for lower sugar recipes will come in a package that will say that it is for lower sugar recipes; it contains more pectin than the other pectin packages.

Powdered pectin is sometimes sold in 49g or 57g packages.  These are interchangeable.

Recipes may call for powered or liquid pectin.  They are about the same in result.

Check the expiration date on the package.  Out of date pectin may not allow the fruit to jell properly.

When adding powdered pectin, however, be sure it is added to the fruit, stirred, dissolved and brought to a boil for one minute before you add the sugar.  Most recipes suggest that you bring the fruit and pectin to a boil, and then add all the sugar the recipe calls for all at once to the boiling liquid.

On the contrary, liquid pectin is used in just the opposite manner.  Bring the fruit, sugar (and lemon juice, if used) to a good hard rolling boil for one minute, first, then add the liquid pectin, stir, and boil for only one minute longer. 

Pickling Lime.  This is calcium hydroxide, not garden lime;  it is safe when handled properly. Use this in a well-ventilated area so you don’t inhale it inadvertently.  Be sure to rinse away from food products and all containers and your hands, thoroughly.  After the 3 hour lime soak, be sure you thoroughly rinse the ingredients three times and hand inspect each part to be sure you get all the lime off the ingredients before proceeding.  The lime may leave a residue on your pot, glass, or sink; if so, you can clean this off easily with a product called Lime-Away that you get at the grocery store in the cleaning supplies department.  Squirt the Lime-Away onto the sink, pot, or whatever, slosh it around, pour it out, and wash the pot or whatever thoroughly with soap and water.  This product is good for the dishwasher too, especially if you have hard water or minerally water.

Butter or margarine, ½ teaspoon in a pot of boiling fruit for jelling or jamming can reduce the amount of foam that otherwise accumulates on the top; if you don’t want to add this, you can simply spoon off  the foam.

Vinegar.  When pickling, apple cider vinegar has a better flavor, but the product will turn dark after a bit of time in the jar.  This does not necessarily mean the product is spoiled.  Distilled vinegar will give a clearer product that will not turn dark.

Spices.  Leaving pickling spices in the jar before sealing the pickles may cause the vinegar to darken over time.

Any spice left in the canned jar continues to season the product further over time.  This is true for the seasoning in salsas also.  This can be a good thing, or not, as your taste dictates.

Tomatoes:  The acid in tomatoes can interact with aluminum, copper, brass, galvanized or iron equipment, creating bitter flavor and undesirable color.  Use stainless steel saucepans and utensils when processing tomatoes.

To avoid unattractive separation of tomatoes into solids and watery juice in a jar of canned tomatoes, prepare small batches at a time for canning, so that no tomato is cut, peeled or whatever before heating and/or is exposed to much air before processing.

To peel tomatoes, before cutting into the tomatoes, slip them gently into boiling water for 30 seconds or until skin cracks, remove, plunge into ice water, the skin slips right off, peel, and put in jar, filling jar as quickly as possible and then closing and processing right away to avoid separation.  Tomatoes should be processed in a pressure cooker these days, as the new varieties of tomato are low in acid.

It is not necessary to add salt to processed tomatoes, unless you like the taste, but some of the new varieties of tomatoes are low in acid, so it is best to add a bit of lemon juice (or citric acid) and salt to be sure they process correctly.  One tablespoon of bottled lemon juice per pint, or ¼ teaspoon citric acid per pint, ½ teaspoon of salt per pint.

Did you know that the lycopene, an antioxidant linked to reducing the risk of certain cancers, is high in tomatoes, and is more readily absorbed from cooked or processed tomatoes than from fresh ones?  Yep.

For further information on canning tomatoes, see this Post:  Canning Tomatoes.

Preparing jars for canning:  NOTE:  Follow the instructions in your recipe and your cooker, exactly.  These notes are general information, and you need the exact time and temperature and directions from YOUR OWN cooker or recipe to be sure you do it correctly.

Use only official canning jars, lids and rings.  Inspect for any cracks or chips and discard any jar with these.  Wash jars and rings (not the lids, which must be new) with soap and water.  You can wash them in dish washer, of course.  But it is not actually necessary to sterilize the jars before canning, only that they be clean.  The processing itself sterilizes the jar and the food, killing any bacteria, etc.

Place the NEW lids in warm/hot water in a shallow bowl, ready to use.  Have the clean rings ready also.

Place clean jars on a rack in a large pot with water up over the top of the jar;  heat the water till it is simmering, thus heating the jar.  To avoid drastic changes in temperature, causing breakage, you want the jars to be warm/hot before you place hot food or liquid in them.  So having heated them in the pot already, extract a jar from the pot of water with the jar handler tool, pour the water back in the pot, and fill the jar as the recipe dictates.

After filling the jar with food, leaving amount of headspace your recipe dictates, use a thin rubber spatula (not metal) and insert it once or twice into the hot food in the jar, allowing all air bubbles to escape.

Use paper towel or clean cloth and clean the edges and rim of the filled jar.

Remove a warm/hot lid from the bowl of warm water, place it carefully on the jar of food, add a clean ring, adjust ring to a good tight seal, by hand only.

Place the jar back in the pot of water, if you are using the water bath canning method, or in the pressure cooker if you are using that.  The pressure cooker should have warm water up to about half way up the side of the jar, or rather, in the amount the pressure cooker directions indicate.

When the pot or cooker is full of jars, put the lid on the pot or cooker, (do not put the “jingler” on the pressure cooker yet), and heat the water in the pot or cooker to a hard, rolling boil.

For the water bath method, let the water continue to boil at a hard boil for the number of minutes indicated by your recipe, then remove the lid, let the jars sit for about five minutes, then remove the jars.

If using the pressure cooker, after you fasten the lid and the water comes to a boil, steam will come out the little opening;  let it do so for five minutes, then put the “jingler” on as indicated for your recipe, reduce the temperature under the pot so that the pot jingles appropriately and continuously during the allotted cooking time, then turn off the heat but DO NOT REMOVE THE JINGLER or open the pot.  Let the steam reduce in the pot naturally, as indicated in the cooker’s directions.  When it is safe to open the pot, do so, remove the jars with the jar handler tool.

When removing the jars, do not tilt them or shake them up so that the ingredients press on the seal.  Set them carefully on a board or cloth, not on a cool surface lest the change in temperature causes the jar to break.  Let them cool completely.  Listen for the “ping” as the lid seals.  When it seals, the center of the lid will be concave.

After 24 hours, remove the rings, gently wipe clean the edges of the jar, the lid, and the inside of the ring.  It is not necessary to replace the ring, but I think it is a good idea to do so to avoid the lid being bumped in the storing time before use of the product.

Store in a moderate temperature out of the sunlight.  The product continues to be seasoned by the seasonings in the jar.  The product may begin to lose flavor after a year or so.

Freezing Foods:

More nutrients are preserved by freezing than by canning, but changes in environment in self-defrosting refrigerators can affect product after a few months.

 Label foods with date, and shuffle them around accordingly, using them within a few months if possible.

Here’s some tips:

 Tomatoes can be washed and frozen whole, just as they are, but it is best to peel them first, as indicated above, and then freeze them.  You don’t have to process them in any way.

Peppers can be frozen “as is.”  I chop them up, put them in little bags or in small containers, in amounts I will need for recipes, and freeze them that way.

Peeled ripe bananas can be frozen and then later popped into the blender for smoothies.

Preparing Veggies for the Freezer:

Blanch all veggies except tomatoes and peppers by placing them in a “basket” that you can insert into boiling water on the stove.  Leave them in the water the amount of time the specific veggie requires, then remove and plunge them into ice water.  Drain and package for freezer.

Appetizers made ahead and frozen on a cookie sheet or the pan you will cook them in are wonderful time savers and let you be present to your guess when you have a party.

Prepare fruit filling for pies, place freezer wrap inside the pie pan you will later use when you bake the pie, put the fruit filling in the freezer wrap, and let it freeze in the exact shape it will be baked in (bad grammar, but you get it, right?)  That makes it really easy later just to get out your pie pan, pop in the still mostly frozen fruit filling, and put it in the oven.  No bother.

Use ice trays to freeze small amounts of stuff  in appropriate sizes for recipes; such as broth, pesto, fruit juice.  Simply fill the ice tray, put it in the freezer, let it freeze.  When the food is frozen solid, remove the cubes and put them all into a freezer bag, label the bag, and pop back in the freezer.  Then you can take out one or two cubes at a time for use.  Great for adding broth to make gravy, or for making pesto in just the time it takes to cook the noodles.  Put the frozen cube of pesto in a stainless serving bowl that fits over the heating water; the pesto cube melts while the noodle cooks.

Some other foods do well being frozen unwrapped by placing them on a cookie sheet and freezing them, especially if they are delicate, and then packaging them.

I don’t use aluminum foil in packaging freezer goods, as it can be corroded by the acid in certain foods.  The plastic freezer bags or food saver sealed bags are great instead.  Be sure to squeeze out all air.

Mason jars can freeze safely, but use the wide-mouthed jars; it’s hard to get frozen food out of narrow-necked jars until the whole thing thaws, and that can be problematic.

Refreezing vegetables, meats and fruits is ok as long as there are ice crystals still in the food, but use them soon.  Seafood and fish should never be refrozen.

Buy things in bulk or on sale and freeze; helps the budget.

Creamed sauces thickened with ClearJel instead of flour will not separate when frozen, as regular sauces thickened with flour tend to do.

Leftover broth can be frozen and used in soups; I freeze it in ice trays, as it is handy to add a little broth here and there.

Leftovers in general that would be appropriate for soup can be frozen in little bits as they happen to be left over, and then when you make a soup you just pop the frozen leftovers into the soup pot.

Don’t freeze: 

The whites of hard boiled eggs turn rubbery when frozen.

Some cheeses do too unless cut in small chunks or grated (I don’t know why that helps, but it does.)

Don’t freeze cake batter, cream fillings, puddings, custards, mayonnaise, potato salad.