Showing posts with label Canning 101. Show all posts
Showing posts with label Canning 101. Show all posts

Oct 11, 2018

The Importance of Headspace in Canning

What is Headspace in Canning
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 I cannot tell you how happy it makes me to see more and more people learning to can food at home. I have noticed, though, that many newbies proudly showing off their work online are making some mistakes. Totally normal! None of us knows everything about canning when we first start out. But one mistake I see a lot is ignoring headspace.

Headspace is the amount of unfilled space between the food in the jar and the rim (top) of the jar. Using the correct headspace not only ensures a good seal on your home canned foods, but it also prevents some potentially dangerous situations.

Why Correct Headspace Matters

Using too little headspace means the jarred food can't properly burp or expand during the canning process. This means the food is forced out of the jar, leaving particles behind on the jar rim. This, in turn, means the lid can't properly seal. From what I've seen, the most common occurrence of using too little headspace is in pie filling. Usually 1-inch headspace is called for - and while that might seem like a huge amount of "unused" jar, the truth is pie filling expands a lot once it's processed.

A much more common problem (and one I battled with when I was new to canning), is leaving too much headspace in the jar. This keeps air in the jar, making the food inside darken over time. Worse, it can potentially lead to food spoilage, even when the jars seal.

Whatever recipe you use should always indicate what headspace is required. (If it doesn't, it's a sure bet it's not a tested safe, "approved" recipe and therefore you shouldn't be using it.) Generally speaking, though, jams, jellies, and juices require 1/4-inch headspace, fruit requires 1/2-inch, and things that go into a pressure canner (low acid foods) need 1-inch headspace.

Bubbling is Vital

In home canning, "bubbling" refers to taking a plastic device (like a plastic spoon handle) or wooden skewer and running it between the jar and the food to remove air bubbles from the jar. (Never use metal for bubbling, since it could damage jars, causing them to break.)

If you don't bubble jars, you may end up with false headspace - that is, you may think you have the correct amount of headspace, but once air works out of the jars during processing, the contents will fall, leaving far more headspace than is ideal.

Courtesy Tom Head
By the by, if you discover air bubbles in your jars after processing, don't worry. You will never get all the air out of the jars. The idea is simply to remove as many air bubbles as possible.

What About After Processing?

Sometimes when you remove jars from the canner, you may find the headspace has changed. Usually, the headspace now looks bigger, but sometimes it may seem to have disappeared. This is nothing to worry about. If you start out with the correct headspace when the jars go into the canner - and the lids seal - the food is safe to eat and store on a shelf.

Sometimes you'll end up with increased headspace because hot food may shrink during the canning process. Other times the increased headspace is caused by "siphoning," or loss of liquid in the jars due to improper technique. Siphoning is generally caused by raw packing (not pre-heating) food that is canned in a heavy syrup; not allowing the jars to cool in the canner a full 5 minutes after processing; or simply running the canner at too high a boil. The end result may be food that discolors at the top, but this is not a safety issue.

If you neglected to bubble your jars and the headspace drops, you could end up with a poor seal on your jars - which could potentially release during storage and lead to spoiled food.

How to Measure Headspace Accurately

If you're just starting out, it's helpful to actually measure your jars' headspace, rather than eyeball things. Back when I was learning to can, I used an old fashioned ruler for this job, but nowadays, there's an even better tool, called (creatively) a headspace measuring tool. This is better than a standard ruler because  it latches onto the jar rim, making for more accurate measuring. (Most headspace measuring tools double as bubblers, too.) To use this type of ruler, hold it upright, with the tip inserted inside the jar. The food should just touch the tip of the correct measurement on the ruler. If you've over-filled your jar, spoon out some of the food. If you've under-filled the jar, add a little food and re-bubble.

Here's Ball's version of a headspace measuring tool.

And here's a less expensive version.

Once the jar is bubbled and the headspace is correct, wipe down the rim of the jar with a damp cloth. Better yet, wet the cloth with a little white vinegar; this helps remove sticky and oily substances better than just water. This step helps ensure a good seal.

Another option, though possibly not as accurate, is to use a canning funnel with headspace marks on it. (Here is a partially stainless steel version.)

When you become a more experienced canner, it's acceptable to eyeball headspace. To aid in this, use the jar's threads. Turn the jar so you can see all three threads. The first thread (the one closest to the jar rim) is where the 1/4 inch headspace mark is. The middle thread indicates 1/2 inch. Just below the last thread is the 1 inch mark.

By paying attention to headspace, you'll improve your canning tremendously, ensuring all the food you can is safe to eat. A little attention to this detail now, and you'll have home canned food that will last many years to come.
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Dec 6, 2016

Pressure Canners vs. Pressure Cookers

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 Since buying my Instant Pot, I've spent a fair amount of time in online groups devoted to pressure cooking, and one question that seems to come up over and over again is: How do I can food in my pressure cooker?

The simple answer is: You can't. At least not safely.

Pressure cookers are not designed for canning. (Although a few pressure canners can be used for both canning and cooking.)

Here's why:

Pressure cookers are smaller and designed for fewer contents (including water) than pressure canners are. Pressure cookers come up to pressure and go down to zero pressure in considerably less time than a pressure canner. While that might sound like a good thing, it actually means canned goods would not be processed for a long enough time, which would lead to your food in jars being unsafe. In other words, a pressure cooker used as a pressure canner won't kill the microorganisms that could make you sick (or even kill you).

Yes, some manufacturers do say you may can in their pressure cookers, but both the National Center for Home Food Preservation and USDA do not recommend them for this use. The risk simply isn't worth the convenience.

Mar 22, 2016

What You Need to Know about Home Canning and Botulism

Recently, Rene from Faith, Farm, and Family Table typed to me: "I want so badly to can meat but I am terrified of poisoning my family...I know you just have to follow the process of pressure cooking, but is there any other major things I should know?" Rene's fear of pressure canning in general or canning meat in particular is incredibly widespread...but, like many fears we have, are easily dashed aside when hit with a good dose of facts.

Water Bath vs. Pressure Canning
The difference is important!

First, let's define some important terms, so we're all on the same page.

A water bath canner is a large pot with a loose lid. In fact, you can use any large pot for water bath canning, as long as it has a lid and a rack on the bottom that prevents the jars from touching the bottom of the pan.

A pressure canner is also a large pot, but it must be made for the specific purpose of home canning. It's lid fits tightly and has a pressure relief valve and a gauge that helps canners monitor the pressure inside the pot. It is not the same thing as a pressure cooker. (Although some pressure canners may also be used as pressure cookers, no pressure cooker can safely be used as a pressure canner.)

Okay, now that' out of the way, let's talk about not killing your family through home canning.

The Big Fear: Botulism

Botulism is a bacterium that's everywhere in our environment. It loves lows low-acid, oxygen-free, high-moisture environments and it can't be killed by boiling, freezing, drying, most household cleaners, or even by radiation. It's nasty stuff. As Erica Strauss of Northwest Edible Life has pointed out, just a single pint jar of pure botulism would kill everyone on the planet. No wonder home canners are afraid of it.

Thankfully, botulism poisoning is very rare. In the U.S., the Centers for Disease Control (CDC) receive about 145 reported cases of botulism poisoning yearly. Only 15% of these cases are associated with food. However, among those cases 38%, are from improperly home canned vegetables.

What Kills Botulism

There are two ways to ensure your home canned food does not kill somebody (or make them ill). The first involves the acidity level of the food, and the second has to do with heating the food.

Botulism hates a high-acid environment. That means if your canned food is high enough in acidity, botulism can't make you sick. Foods that are safe to water bath can must have a high acidity level - 4.6 or higher. Anything below that level of acidity must be pressure canned, or indeed, it might make someone very, very sick.

(As an aside, the most common excuse for water bath canning low acid foods, like vegetables, is "But my grandmother did it and we're all still alive!" That's rather like saying, "But I drive home drunk every night and I haven't gotten into an accident yet!" And, in fact, many people who can this way do get sick off their home canned food. Not all food poisoning is botulism, after all, and most food poisoning is mistakenly thought a "24 hour stomach bug.")

So, to be clear, jams, fruits, and fruit juices are high acid and generally safe to water bath can. (But always check The National Center for Home Food Preservation (NCHFP) to be doubly sure.) Vegetables, meats, and legumes are low-acid and must be pressure canned. An exception is pickled vegetables, which (because of high levels of acidic vinegar) are water bath canned.

So why does pressure canning work with low-acid foods? Because it gets the temperature of the food up to 240 degrees F. (much hotter than in water bath canning), and botulism can't live at that temperature. Even then, however, that temperature must be kept for a certain length of time for the spores to completely die off.

The Easy Way to Prevent Botulism

Hopefully, now you can see why approved recipes - recipes that have been tested in a lab - are vital to safe home canning. Most home canners have no reliable way to test the acidity of the food they are canning, nor do they have a way to know they've cooked food long enough to kill botulism. 

When we hear about home canners giving themselves or others botulism, they've always made egregious choices. For example, in 2013, a Washington man nearly died of botulism after consuming elk meat he'd processed in a pressure cooker (not a pressure canner - first problem) for a far shorter time than he should have (second problem). When the lids started coming off his jars while in his pantry, instead of throwing the meat away, he ate it (fourth problem). Oy! In 1997, an Illinois man came near death after eating home canned pickled eggs. That's right; there is no approved home canning recipe for eggs of any type. And in 2015, someone poisoned everyone at their church picnic (killing one) by serving improperly home canned potatoes. Many news reports hint that the potatoes were canned in a water bath canner, instead of a pressure canner.

Never change a canning recipe in any way, and your home canned foods will be perfectly safe.

As you become more experienced, you will find you can change the spices in recipes like stew, or create your own soup using NCHFP's guidelines. But never change what type of canner you use, or how long the processing time is, or can anything that the NCHFP says shouldn't be canned. (That includes all dairy, eggs, anything with flour, and anything so dense it can't be heated through - like pureed pumpkin or very thick applesauce.)

So how easy is that? Just use approved recipes from a source like Ball or NCHFP. Easy peasy!

Just in Case...

If you simply follow tested recipes, it's highly unlikely you'll ever get food poisoning from your home canned foods. However, there are a few other guidelines you should bear in mind:

* Never store your home canned food with the rings on. Sometimes jar lids unseal. If you leave the ring on the jar, it may reseal; bacteria will enter the jar, and you'll never know the food is contaminated. If you leave the ring off the jar, however, it will not when you discover the open jar in your pantry, you will throw the whole thing away, rather than eat it.

* Don't stack anything (other jars, commercially canned food, etc.) on top of jars. Again, this can make lids open and reseal, just like keeping the rings on does.

* Store your home canned food in place where temperatures don't fluctuate and it is neither hot nor cold. (If you're comfortable, so are your jars of home canned food.)

* Pay attention when you open a jar of home canned food. If the seal isn't tight, don't eat the food in the jar.

* If you find a jar with a bulging lid, it is contaminated; don't eat it.

* If you open a jar and liquid or foam squirts out, the contents aren't safe to eat.

* Smell the food while it's still in the jar. If it smells off in any way, do not eat it.

* If there is any mold in the jar, toss the jar.

* If you do suspect any home canned food is spoiled, place the jar and food in a plastic bag, seal it, and dispose of it in the trash. Wipe up any spills with diluted bleach (1/4 cup bleach to 2 cups of water, according to the CDC).

Knowledge is power, my friends. And home canning isn't difficult. It is perfectly safe to use a pressure canner. Just use a trusted recipe!

Jul 30, 2014

10 Common Canning Myths - Debunked!

Home canning isn't difficult. But perhaps because it's evolved over the years, there are many myths associated with it. If you're afraid to can, or you just want to become a more expert canner, check out these common canning myths - and the real facts behind them.

Myth 1: There's no way I'm home canning anything. I'm not going to risk making my loved ones sick  - or evening killing them with botulism!

The Facts: Modern canning is quite safe as long as you follow a modern canning book, like The Ball Complete Book of Home Preserving or the guidelines at the National Center for Home Food Preservation (NCHFP). The steps are simple and when followed completely, you won't get botulism. (If you've read some recent news stories about home canners getting botulism from their home canned food, please note they did not even come close to following proper canning guidelines! Don't skip steps. They are there for a reason.)

Myth 2: I can in an oven. My grandma did it, so I know it's safe.

The Facts: Oven canning is not safe, and never was. This is because the oven doesn't get the food hot enough to kill all the bad bugs.

Myth 3: Butter is totally safe to can.

The Facts: Dairy products aren't suitable for home canning. Learn more here.

Myth 4: Canning lids contain BPA - a chemical I don't want in my diet.

The Facts: Ball and Kerr lids are now BPA free, as are Tattler lids.

Myth 5: It's okay to store my jars with rings on them. It's also okay to stack jars one on top of the other during storage.

The Facts: Both are highly discouraged; here's why: When you leave the rings on canning lids, or when you put something on top of the jars, those jars may unseal - then reseal themselves. This can result in spoiled food - but you won't be able to tell it's spoiled (unless it happens to grow mold or take on a strange smell - which may or may not happen). On the other hand, if you leave the rings off and don't put anything on top of the jars, if they happen to unseal, you'll know about it! The lids won't be able to reseal because there will be no pressure on them, so it will be obvious there's a problem with the seal. (FYI: It's not often that canning lids come unsealed, but under the right conditions, like exposure to too much heat, they may.)

Myth 6: There's no need to boil or simmer lids. They get sterilized during canning, anyway.

The Facts: The purpose of simmering (not boiling) canning lids is not to sterilize or clean them. It's to heat up the rubbery part so it will properly seal the jar. So yes, you do need to simmer them before placing them on jars. The newest canning lids do not require boiling or heating before placing them on canning jars and processing them in a water bath or pressure canner.

Myth 7: It's okay to can vegetables in a water bath canner. My grandmother did it all the time!

The Facts: There was a brief period where some put up vegetables in a water bath canner. But that was before we knew as much about food poisoning as we do now. In addition:

* People rarely died from this unsafe type of canning because after they opened the jar of canned food, they boiled the vegetables to death. This killed all the bad bugs - but it also made the food mushy and removed much of the nutrition from it.

* We now have bacteria and other bugs in our environment that grandma did not.

* Even in Grandma's day, this was risky. It just isn't worth the risk - especially when you can easily can vegetables in a perfectly safe, easy to use pressure canner.

Myth 8: I don't put my jams, jellies, or tomato products in a canner. I just sterilize the jars, put the food in, put the simmered cap on, and turn it upside down. It seals fine!

The Facts: This is the traditional method for canning jams and jellies. However, a quick 10 minute boil in a water bath canner makes the food safer to eat. It's not difficult or time consuming, so why risk making someone sick with unprocessed jams and jellies?

As for tomato products, it's very risky not to process them in a canner. When you cook tomato sauces and other tomato products on the stove, they don't get hot enough to kill bad bugs.

In addition, modern tomatoes may have less acid in them than old-fashioned tomatoes; lower acid means a greater risk for food poisoning, unless the tomatoes are processed in a canner. In fact, some experts recommend only canning tomatoes and tomato products in a pressure canner, to reduce the risk of illness even further.

Myth 9: I can make up my own recipes to home can. I don't have to follow a recipe that's been tested in a laboratory for safety. After all, the canned foods we buy in a store aren't made from "approved" recipes.

The Facts: First, the commercial canning process is entirely different from home canning. And yes, commercially canned recipes are tested for safety - the recipes just aren't shared with the public and are only safe with commercial canning methods.

That said, it's possible to create safe jam recipes, as long as you understand the important balance required to make jam or jelly. In addition, there is some leeway when it comes to soups, as long as you understand density and that some foods just aren't appropriate for canning. However, it's wise for new canners to stick to approved recipes, such as those found in the Ball canning books or on the NCHFP website. In addition, you may wish to check out the books Putting Up and Putting it Up More by Steve Downdey, which explain the process cottage canning businesses use to come up with their own recipes. (Be forewarned; these books are controversial because they set forth not home canning guidelines, but guidelines used in commercial kitchens.)

Myth 10: I always sterilize my canning jars and lids. It's the only safe way to go!

The Facts: It's almost never necessary to sterilize jars and lids before filling them with food. That's because the canning process itself sterilizes them. Learn more here.

Dec 4, 2013

Best FREE Canning Jar Labels on the Net

Home canned foods and gifts in a jar both make excellent Christmas gifts. Not only are they yummy (or, in the case of some gifts in a jar, useful), but they say "You cared enough to take the time and creativity to make this for me." In years past, I've discussed some fun ways to dress up your jarred gifts, but this year I specifically wanted to focus on labels. There are a ton of free jar labels available online - just print them off, cut them out, and attach. But to help you wade through all those offerings, I've rounded up what I consider the very best the Internet has to offer.

Canning Jar Top Labels

These are the type of labels designed to fit on the lid of canning jar. You may either glue these labels on top of the lid or simply set them on top of the jar lid and hold them in place with a jar screwband.

* Beautiful, old fashioned labels for blueberry, peach, apricot, grape, cherry, raspberry, strawberry,
Old fashioned labels from World Label.
bumbleberry (mixed berry), and marmalade.

* Simple "homemade" labels

* Colorful stripes

* Black and white Art Deco inspired

* Candy stripes

* Simple "Homemade Just for You"

* Green and blue stripes

* Flower power

* Several styles of vintage labels

* Classy chalkboard style

* Plaid, polka-dotted, and starburst labels

* Pretty fruit labels for berry, cherry, raspberry, and strawberry jam

* Citrus

* Antique-style

* "Spread Love" labels and tags

* Apples

Mason jar labels from
* Blue, maroon, gold, and green print

* Cute fruit labels

* Colorful polka-dots and stripes

* Christmas trees

* Red and white "Jam Made with Love By..."

* Beautiful fruits: cherry, peaches, lemons, tomato, pear, grapes, pumpkin, strawberry, currents, raspberry, and blackberry.

* Photos of real food: apple, tomato, cucumber

* Sunbursts

* Simple "Made With Love"

* "Farm Fresh"

* Red, blue, and green gingham

* Snazzy black, white, and color labels

* Flowery black and white

* Colorful leaves

* Green leaves and grass

* Mason jars

* Old fashioned strawberry jam

Christmas presents and penguins from World Label.
* Applesauce

* Pretty vintage

* Red and white striped, snowflakes, and holly labels

* Christmas lights

* Christmas presents and penguins

Canning Jar Front Labels

These labels are designed to glue on the front of a jar - just like labels on grocery-store purchased canned goods. For best results, print on paper with a sticky back.

* Sweet cherry jar labels

* Cute blue and red "Made with Love"

* Red gingham
Old fashioned strawberries from Happy Miscellany.

* Colorful polka-dots and stripes

* "The Jam Labelizer:" choose from several fonts and colors

* Christmas and winter theme labels

* Apple pie

* Old fashioned strawberries

* Fruity labels

* Vintage

* Red and white striped, snowflakes, and holly labels

* Elaborate antique

* Modern blue and gold 

Canning Jar Tags

These tags tie on with string or ribbon.

* Cute "What's Inside" tags
Mason jar tags from Cottage Industrialist.

* Mason jar tags

* Rustic tags for strawberry, peach, cherry, plum, blueberry, raspberry, mixed berry, damson, and blackberry jams (also orange marmalade)

* Patterned mason jars

* "Spread the Love"

* Cute strawberries

* "Homemade Salsa"

* "Farm Fresh"

* Christmasy birds

* Merry Christmas

Other Ideas

* Use old Christmas cards to create jar labels.

* Use muffin liners as decorative toppers. Or use brown kraft paper. Tie with string, or just put a jar ring on.

Aug 21, 2013

When & How to Sterilize Canning Jars

A few days ago, I read an article in one of the country's most famous cooking magazines (affiliated with a very famous television network), trying to explain how to can tomatoes. It was riddled with errors – none of which were going to lead to food poisoning, thank goodness. But it was yet another reminder that as canning gains popularity again, there’s an awful lot of misinformation out there.

One area that many, many canners seem to find confusing is when to sterilize jars.

Why Sterilize Canning Jars?
The only reason to sterilize canning jars before canning is if the processing time is very short. Otherwise, the jars and their contents will be perfectly sterilized during the processing time - assuming you're using an approved recipe from Ball or the National Center for Home Food Preservation. (All canning recipes here at Proverbs 31 Woman are from one of these sources.)

When to Sterilize Canning Jars 
It is only necessary to sterilize canning jars before filling them if the processing time is under 10 minutes. Very few things fall into that category: Some jellies, jams, marmalades, and similar preserves, and perhaps some pickles in smaller jars, for example.

Anything that is processed more than 10 minutes is put in clean, hot jars that don’t need sterilizing first.

Jars in the Canner Aren't Sterile
Some people think if they put their jars in the canner and turn on the heat, making the water hot (and perhaps even simmering), they are sterilizing the jars. This is not true. This keeps the jars warm before filling them - which is necessary in order to prevent jars from breaking - but the jars aren't actually getting sterilized. (There are other ways to keep jars warm, too, including in a clean sink of hot water and in a dishwasher that has a hot "drying" temperature. I do not recommend keeping them hot in the stove, since this can lead to temperature fluctuations that can make jars break.)

How to Sterilize Canning Jars
There are people who recommend sterilizing canning jars in the oven or the dishwasher, but the only safe way to get them sterile is to boil them. Here’s how:

1. Fill your canner with water so it comes at least 2 inches above the tops of the jars. Be sure there is a rack in the bottom of the canner.

2. Add the canning jars and bring to a boil. Boil for 10 minutes.

3. Now just leave the jars in the canner until you are ready to fill them. (Don’t take them out of the canner and let them air dry.)

It’s that simple!

Jun 21, 2013

Canning Q & A 2013

Q: Is it true canning lids contain BPA?

A: Older canning lids did contain a layer of BPA sandwiched in between the metal layers, but new Ball and Kerr canning jars no longer do. Look for lids marked "BPA Free." (Ball actually began selling BPA free lids last fall, so you can check the production date on boxes, too.)

Q: A friend told me I shouldn't store my canned jars with the rings on. I like the convenience; is there really a good reason why I shouldn't?

A: Here's why it's best to NOT to store home canned jars with jar rings on them: If, for some reason, the seal on the jar lid breaks free, the ring holds the lid in place and makes it possible for the jar to re-seal - and then there's no way to know whether or not the contents of the jar are still safe to eat. (While you should always smell the product and look for mold, sometimes food can be spoiled and show no signs of it.) So, yes, you really should store your jar rings elsewhere.

(c) 2013 by Gretchen Harris.
Q: When a recipes calls for hot jars, does it mean just wash them in hot water?

A: No. When a canning recipe calls for putting food in hot jars, it means the jars must be pre-heated. Otherwise, the jars may break during the canning process, or the contents of the jar may not reach the temperature required to kill off harmful bacteria. There are several ways to keep jars hot before filling them:

1. Place them in the canner (with both the jars and the canner filled with water) and heat the water until it steams.

2. Place the jars in a sanitized sink full of hot tap water; this will require adding fresh hot tap water periodically.

3. Wash the jars in a dishwasher and keep the dishwasher on the hot dry cycle until you're ready to use the jars.

4. Place the jars in a roasting pan with several inches of water in it and place the whole in a warm oven.

The latter method should not be confused with sterilizing jars in the oven (which is not perfectly effective) or oven canning, which is not safe.

Q: I recently canned something from the Ball Complete Book of Home Preserving and I ended up with fewer pints than the book said I would. Is that typical?

A: It depends on how you determine how much produce to use. If you go by number (for example, 20 tomatoes), you may get more or less finished product because produce varies so much in size. For the most accuracy in how much end product to expect, go with the recipe's weight recommendations (for example, 10 lbs. of tomatoes). Even then, however, the recipe only offers an estimate of how much canned food to expect.

Q: For water bath canners, do you need to only use 2 inches of water? 

A: No; you must use more than that. The water in the canner should cover the tops of the jars by at least one inch in order to have safely home canned food.

Check out previous' year's Canning Q & A:


Mar 29, 2013

Canning Glossary

Ever bump into a canning term that leaves you scratching your head? Learn what that term means here, in Proverb's 31 Woman's Canning Glossary. Can't find a certain term listed? Be sure to email me ; I'll provide an answer and add the term to the Glossary!

Alum: In older prickling recipes, alum is sometimes called for to add crispness. However, large doses of alum can cause illness, including nasea and gastrointestinal problems. Therefore, it's no longer recommended for pickling.

Ball offers approved recipes.
Approved Recipe: A canning recipe tested and approved by the USDA. You will find approved recipes in modern day canning books, such as The Ball Complete Book of Home Preserving, The Ball Blue Book, at the website of the National Center for Home Food Preservation - and on this blog! Following non-approved recipes, or older recipes (even from the 1980s), is not considered safe because we now know more about food acidity and temperatures needed to kill harmful bacteria. The old canning rules simply aren't as safe as the new ones.

Ascorbic Acid: The scientific name for vitamin C. When used in canning, it prevents the discoloration of fruits and vegetables.

Bacteria: Microorganisms that are found everywhere. Certain bacteria can lead to serious illness or death in humans and may thrive in low-acid, home canned foods that aren't heated to 240 degrees F. for a specific period of time. This is why low-acid foods (like vegetables and meat) must be canned in a pressure canner.

Blanch: In cooking and canning, to blanch means to place food (usually vegetables or fruit) in a pot of boiling water for a very short period of time, then immedietly place the same food in ice water. The process preserves color and texture and makes it possible to easily remove the skin or peel of certain fruits. (Removing the skin or peel isn't merely for aetetics; the outer part of certain foods is more likely to contain bacteria.)

Boil: Heating liquid until bubbles burst over the surface. See also "Boil Gently," "Simmer," "Full Rolling Boil," and "Boiling Point."

Boil Gently: See "Simmer."

Boiling Point: The temperature at which liquid reaches a boil - 212 degrees F. at sea level.

Full Rolling Boil: Boiling rapidly; stirring does not prevent the liquid from continuing to boil. To obtain a gel in jam or jelly, it's vital to cook at a full rolling boil.

Boiling qater canner
Boiling Water Method: Also called "Bath Water Method." This is one of two ways to home can food and is used only for high-acid foods such as fruits, pickles, and jams. When jars of food are surrounded by boiling water and a temperature of 212 degrees F. is maintained, harmful bacteria is killed, making the contents of the jars safe for eating.

Botulism: Food poisoning caused by eating toxins caused by the spores of the bacteria Clostridium botulinum. In canning, using only approved recipes with correct processing times, and using the proper canning technique (boiling water vs. pressure canner) prevents botulism.

Brine: Salt-water (with or without added herbs) used in pickling.

Bubble Remover: A canning tool that's shaped like a stick and is not metallic. To use, it is moved straight up and down in the jar to remove most air bubbles. A handle of any non-metallic utensil (such as a spoon with a long handle) may be used instead.

Calcium Chloride: A natural mineral salt used to crisp food (especially pickles) in canning.

Candy thermometer
Candy Thermometer: A thermometer with a hook or clip on its side that's used for attaching the tool to a pot or pan. Used in canning when making soft spreads made without additional pectin.

Canner: A specially designed pot used for home canning food. "Canner" may refer to a Water Bath Canner or a Pressure Canner, both of which have very specific uses.

Canning Salt: See "Pickling Salt."

Chutney: Spiced mixtures of vegetables or fruits with vinegar, typically used as a spread for breads or meats.

Citric Acid: A natural acid found in citrus fruits like lemons. Used in canning to prevent the browning of foods or to increase acidity.

ClearJel: A brand name product used as a thickener in canning. Thickeners like flour and cornstarch break down in canning and should not be used. ClearJel does not.

Dial gauge on a pressure canner
Conserve: Similar to jam, made with two or more fruits, plus nuts or raisins.

Cold Pack: To place food inside canning jars when it is unheated and uncooked.

Dial Gauge: On a pressure canner, a regulator that indicates the amount of pressure in the canner. For safety's sake, have your gauge tested every year at a local extension office. Or, buy a weighted gauge for your pressure canner (see "Weighted Gauge").

E.coli: A type of bacteria common in human intestines. A strain, Escherichia.coli 0157:H7, produces toxins that may cause diarreah, headaches, chills, fever, or even death.

Exhausting: See "Venting."

Fermentation: Fermentation is a naturally occurring process caused by yeast. In canning, if yeasts haven't been killed during processing, the food will bubble, become scummy, and break the jar's seal. Some foods are fermented before canning, such as certain kinds of pickles or sauerkraut.
Food mill

Fingertip Tight: A phrase used to describe how snugly jar ring bands should be. To put a screwband on "fingertip tight," use your fingers to turn the band until resistance is met, then tighten just a little further. Over-tightening bands can result in buckled lids or lids that don't seal. Bands that are too loose may also cause lids to not seal.

Food Mill: A device used to puree cooked, soft food, such as tomatoes or apples.

Fruit Butter: A thick, soft spread made by slowly cooking down fruit and sugar.

Funnel: A utensil that sits on top of a canning jar to make packing food into the jar easier and less messy. For canning, it should be plastic, since some foods react with metals.

Gasket: A rubber ring that fits inside the opening of a pressure canner and creates a seal so no steam can escape.

Gel Stage: The point at which a soft spread comes to a full gel: 220 degrees F or 8 degrees F. above the boiling point of water.

Headspace: The empty space between the food in a canning jar and the top rim of the jar. Correct headspace is necessary so food can expand during the canning process, and so a strong vacuum seal can be created, sealing the jars.

Jar lifter
High Acid Food: Food that has enough acid (either naturally or because of an added ingredient) to reach a pH of 4.6 or lower. Fruit (including tomatoes), jams, jellies, and most spreads are naturally high-acid foods. Pickles, relishes, and salasas become high acid due to the addition of vinegar or citric acid. High acid foods should be processed of boiling water canners. (Compare to "Low Acid Food.")

Hot Pack Method: When hot canning jars are filled with hot food prior to processing. (Compare to "Cold Pack.")

Jam: A soft spread made with crushed fruit.

Jar Lifter: A tool designed for safely lifting canning jars in and out of hot water.

Jelly: A soft spread made with fruit, then strained so it no longer has pieces of fruit in it.

Jelly strainer with jelly bag.
Jelly Bag: A cloth bag used to strain jelly. Sometimes a type of colander or strainer lined with two layers of cheesecloth is used instead.

Jelly Strainer: A metal stand with a large ring used for holding a jelly bag over a bowl.

Jelly Thermometer: See "Candy Thermometer."

Kosher salt: A coarse salt without additives like iodine. It is sometimes used in pickling, although (due to variations in granule size) it can be difficult to measure accurately. Therefore, pickling salt is usually preferred for canning.

Canning lids in a lid rack.
Lid: The metal disc that sits on top of the canning jar and is initially held in place with a metal ring. Once the jars are cooled and sealed, the metal ring is generally removed so that if the jars loose their seal in storage they don't reseal potentially spoiled food.

Lid Lifter: A wand-like tool with a magnet at one end, designed for lifting canning lids out of hot water. Lid lifters are no longer necessary, since modern canning lids don't need to be simmered before using.

Lid Rack: A tool designed to neatly hold canning lids in pots of hot water. Lid lifters are no longer necessary, since modern canning lids don't need to be simmered before using.

Low Acid Food: Food that has a pH higher than 4.6. Meat and vegetables are low acid foods - which must be processed in a pressure canner in order to kill harmful bacteria.

Marmalade: A soft, jam-like spread made from citrus and citrus peel.

Open Kettle Canning: An old fashioned method of canning where a canner is not used. Hot jars are filled with hot food and lids are screwed on. As the jars cool, the lids seal. This method does not adequately heat foods and destroy bacteria and therefore is no longer considered safe.

Oven Canning: An old fashioned method of canning where jars are placed in the oven to process. Because it does not adequately heat foods and kill bacteria, it is no longer considered a safe method of canning.

Oxidation: When fruits and vegetables are exposed to oxygen in the air, they oxidize, or turn brown. Oxidation isn't harmful, but may cause textural changes. It can be prevented by keeping cut fruits and vegetables in a bowl of lemon juice and water as you work with them.

Paraffin Wax: A type of wax used to seal jars in an old fashioned canning method. It is no longer used because it doesn't kill all harmful bacteria.

Pectin: A carbohydrate naturally found in fruit and vegetables. In canning, a powdered or liquid form of pectin is used to gel jams, jellies, and other spreads.

Pickle Crisp: A product that uses calcium cloride (naturally found in some salts) to  make home canned pickles more crisp.

Pickling: Preserving food in a vinegar solution, often with added spices. Cucumber pickles are the most common pickled food, but many vegetables and fruits may also be pickled.

Pickling Cucumber: A type of cucumber that is small when mature - typically no longer than 6 inches. For the best pickles, they should be processed immediately after picking off the vine.

Pickling Lime: A caustic white powder (also called "slaked lime") used in some old pickle recipes and designed to add crispness. Because it burns, corrodes, and may increase the risk of botulism, it is no longer recommended for home pickling.

Pressure canner
Pickling Salt: A fine grained salt that contains no anti-caking ingredients or iodine, which can darken pickles and cloud their brine.Also called "canning salt."

Preserves: A soft spread where the fruit retains it shape and is shiny and transparent. Unlike other soft spreads, preserves do not hold their shape when spooned from the jar.

Pressure Canner: A heavy pot with a lid that locks in place and has a pressure regulator. Used to process low acid foods like vegetables and meat. Pressure cookers - similar looking pots used for cooking food - are not suitable for canning; however, some pressure canners are designed to double as pressure cookers.

Pressure Canning Method: A home canning method used to can low acid foods, like meat and vegetables, safely. Because the steam inside the canner is pressurized, it can exceed the point of boiling water (212 degrees F.), which enables the method to kill harmful bacteria in low acid foods.

Pressure Cooker: An air tight pot that cooks food with pressurized steam. Pressure cookers are not the same as pressure canners and should never be used for canning.

Processing Time: The amount of time filled jars are heated in a boiling water canner or pressure canner. Processing times are tested to ensure the contents at the center of the jar reach a temperature that kills off harmful bacteria, and vary according to jar size, contents of the jar, and whether or not the jar was hot packed or cold packed.

Raw Pack: Filling canning jars with unheated, raw food prior to processing them in a canner.

Relish: A pickled food made from chopped vegetables and/or fruits. It is cooked in vinegar and may or may not contain sugar. It is used as a condiment.

Screw bands
Reprocess: Re-can. When a canning jar fails to seal, the contents are reheated according to the original directions, a new lid is put on, and the jars are reprocessed.

Screw Band: A metal circle used to hold a canning lid in place on a canning jar while the jar is being processed. Once the jar is completely cool and sealed, it's best to remove the screw band.

Simmer: To cook just below the boiling point. Bubbles will form in the pot, but will only burst occasionally on top of the liquid.

Slacked Lime: See "Pickling Lime."

Sterilizing: Killing all microorganizsms. In canning, jars don't need to be sterilized before being processed in a canner unless the processing time is 10 minutes or less. To sterilize jars, fill them with water but don't put on lids. Place them in a canner filled with water; bring to a boil and boil for 10 minutes.

Table Salt: A fine grained salt commonly used at the dining table for seasoning. It usually includes anti-caking ingredients and iodine, which can cause cloudy brine or darkened fruit. Pickling salt is preferred for canning.

Vacuum Seal: The state of negative pressure that allows home canned jars to seal and prevent spoilage. When the jar is heated inside the canner, the food and air inside it expand, pushing air out of the jar. When the jar cools and the food inside shrinks, a vacuum forms. The sealing compound on the underside of home canning lids prevents air from re-entering the jar.

Victorio strainer
Venting: Allowing air to escape from a pressure canner OR forcing air to escape a jar during processing in a canner (see "Vacuum Seal").

Victorio Strainer: A tool that separates the skins and seeds of fruit. It also purees the "meat" of the fruit. It is commonly used for making applesauce and tomato paste.
Weighted gauge

Weighted Gauge Pressure Canner: A type of pressure canner that has a three- or one-piece weight on the lid that allows steam to vent. The steam causes the weight to rock back and forth during processing, which indicates the correct pressure has been achieved for safe canning. Unlike dial gauges, which should be tested every year for accuracy, a weighted gauge can be used without special testing.