The tapered jars we use today were introduced after World War II. They use a two-piece cap consisting of a lid and a metal screw band that fits the threaded jar top. Today, all home-canning jars are generically referred to as Mason jars. Thank you, Mr. Mason, for making the task of home-canning easy with the use of screw-top closures.
Lid wand
A lid wand (see Figure 2-11) has a magnet on one end of a heat-resistant stick. With it, you can take a lid from hot water and place it on the filled-jar rim without touching the lid or disturbing the sealing compound.
Place your lids top to top and underside to underside to prevent them from sticking together in your pan of hot water. If they do stick together, dip them into a bowl of cold water to release the suction. Reheat them in the hot water for a few seconds before using them. Also offset the lids as you place them in the water. This keeps them fanned out and easier to pick up singly.
Figure 2-11: A lid wand.
Thin plastic spatula
A thin, flexible plastic spatula is the right tool for releasing air bubbles between pieces of food in your filled jars (check out Figure 2-12). Buy a package of chopsticks for an inexpensive alternative.
Don’t use a metal item or a larger object for this job because it may damage your food and crack or break your hot jar.
Figure 2-12: A thin plastic spatula for releasing air bubbles.
Wide-mouth canning funnel
A wide-mouth funnel (see Figure 2-13) fits into the inside edge of a regular-mouth or a wide-mouth canning jar and lets you quickly and neatly fill your jars. This is an essential tool for canning.
Figure 2-13: A wide-mouth canning funnel.
Jelly bag or strainer
A jelly bag is made for extracting juice from cooked fruit for making jelly. These bags aren’t expensive, but if you’d rather not purchase one, make your own using a metal strainer lined with cheesecloth. Use a strainer that hangs on the edge of your pot or mixing bowl and doesn’t touch the liquid. Head to Chapter 6 for instructions on making jelly.
Stoneware crocks
Stoneware crocks are available in sizes from 1 gallon to 5 gallons, usually without lids. They’re nonreactive and are used for making pickles and olives. Make sure you use only crocks that are glazed on the interior and certified free of lead and cadmium, a form of zinc ore used in pigments or dyes.
Be wary of using secondhand stoneware crocks. These crocks were often made with leaded glaze that will leach into your foodstuff. Because you do not often know the history of used items, this is an item that is best purchased new and not secondhand.
Tools and Equipment for Freezing Food
Some of the items required for this simple form of food preservation are already in your kitchen. For a more detailed list, check out Chapter 13.
A freezer: Usually, the freezer attached to your refrigerator is large enough for freezing food. But if you’re serious about freezing lots of food, you may want to invest in a separate freezer unit.
Rigid containers: These can be made of plastic or glass. Use only containers approved for the cold temperatures of a freezer. Plastic containers should be nonporous and thick enough to keep out odors and dry air in the freezer. Glass containers need to be treated to endure the low temperature of a freezer and strong enough to resist cracking under the pressure of expanding food during the freezing process.
Freezer bags: Use bags made for freezing in sizes compatible with the amount of your food.
Freezer paper and wraps: This laminated paper protects your food from freezer burn, which results when air comes in contact with your food while it’s in the freezer. Tape this paper to keep the wrap tightly sealed. Heavy-duty aluminum foil is another great freezer wrap and requires no taping.
For extra protection against freezer damage, wrap food items in foil and place them in a freezer bag.
Tools and Equipment for Drying Food
Dehydrating food is a long, slow process of removing moisture from your food while exposing it to low heat. Here are some items you’ll want to have for this process, which is explained in Chapter 16:
An electric dehydrator: This machine dries your food in an enclosed chamber while it circulates warm air around your food.
A conventional oven: If your oven maintains a low temperature and you can stand to be without it for up to 24 hours, use it for drying before making the investment in an electric food dehydrator.
Oven thermometer: An oven thermometer tells you if your oven temperature is low enough to dry your food without cooking it (see Chapter 16 for detailed instructions for checking your oven’s temperature).
Trays and racks: These are used for holding your food while it’s drying. They’re included with an electric dehydrator. For oven-drying, use mesh-covered frames or baking sheets. For sun-drying, clean screens are necessary, along with clean cheesecloth to keep hungry bugs off the food as it dries.
Chapter 3
On Your Mark, Get Set, Whoa! The Road to Safe Canning and Preserving
In This Chapter
Putting your fears of home-canned food to rest
Determining your processing method by your food’s acidity
Making the acquaintance of food-spoiling microorganisms and enzymes
Recognizing the signs of food spoilage
The desire and determination to produce a delicious, safe-to-eat product without the risk of food poisoning is one thing longtime canners and people new to canning have in common. The canning and preserving techniques used today provide you with these results as long as you follow the proper steps and procedures for preparing, processing, and storing your food.
Before you begin your canning and preserving journey, take a stroll through this chapter, which introduces you to microorganisms, enzymes, and other potentially dangerous situations that cause food spoilage. You can also find info on how to prevent and identify food spoilage. The technical portion of this chapter shouldn’t deter you from canning. Rest assured, after reading this information, you’ll have no fear about preparing and serving your home-canned and -preserved food.
Dispelling Your Fears of Home-Canned and -Preserved Food
Preventing food spoilage is the key to safe canning. Over the years, home-canning has become safer and better. Scientists have standardized processing methods, and home-canners know more about using these methods. When you follow up-to-date guidelines exactly, you’ll experience little concern about the quality and safety of your home-canned and -preserved foods.
The following sections offer some tips for handling, preparing, and processing your food.
Preparing your food properly
Use fresh, firm (not overripe) food. Wash and prepare your food well to remove any dirt and bacteria: Wash it in a large bowl filled with water and a few drops of detergent and then rinse it in a separate bowl of fresh water (see Figure 3-1). Can fruit and vegetables as soon as possible after they’re picked.
No, you don’t have to wash berries individually: Put them in a colander and submerge the colander, berries and all, in the wash bowl; then rinse them off with a running spray of water.
Figure 3-1: How to wash fruit and vegetables well.
Packing your jars with care
How you fill the canning jars is also important:
Don’t overpack foods. Trying to cram too much food into a jar may result in underprocessing because the heat can’t evenly penetrate the food.
Make sure your jars have the proper headspace. Headspace is the air space between the inside of the lid and the top of your food or liquid in your jar or container (see Figure 3-2). Proper headspace is important to the safety of your preserved food because of the expansion that occurs as your jars are processed or your food freezes.
Make sure you release the air bubbles from the jar before sealing the lid. No matter how carefully you pack and fill your jars, you’ll always have some hidden bubbles.
Figure 3-2: Headspace.
The all-important headspace
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sp; When you’re canning food, too little headspace in your canning jars restricts your food from expanding as it boils. Inadequate space for the expanding food may force some of it out of the jar and under the lid, leaving particles of food between the seal and the jar rim. If this occurs, your jar won’t produce a vacuum seal.
Leaving too much headspace may cause discoloration in the top portion of your food. Excess headspace can keep your jar from producing a vacuum seal if the processing time isn’t long enough to exhaust the excess air in the jar.
Always use the headspace stated in your recipe. If your recipe doesn’t give you a headspace allowance, use these guidelines:
For juice, jam, jelly, pickles, relish, chutney, sauces, and condiments, leave headspace of 1/4 inch.
For high-acid foods (fruits and tomatoes), leave headspace of 1/2 inch.
For low-acid foods (vegetables, meats, fish, and poultry), leave headspace of 1 inch.
Headspace is also important when you’re freezing food because frozen food expands during the freezing process. If you fail to leave the proper headspace in your freezer container, the lid may be forced off the container, or the container may crack or break. When your frozen food comes in direct contact with the air in your freezer, the quality of your food deteriorates and the food develops freezer burn (go to Chapter 13 for more on freezing food). On the other hand, too much air space allows excess air in your container. Even though your food doesn’t come in direct contact with the air in the freezer, the excess space in the top of the container develops ice crystals. When your food thaws, the excess liquid reduces the food’s quality.
If you don’t trust yourself to eyeball the headspace, use a small plastic ruler (about 6 inches long) to measure the correct headspace in the jar.
Releasing air bubbles from your jars
The most important thing to do when you’re filling your jars is to release trapped air bubbles between the food pieces. This may seem unimportant, but air bubbles can play havoc with your final product:
Jar seals: Too much air in the jar from trapped air bubbles produces excessive pressure in the jar during processing. The pressure in the jar is greater than the pressure outside the jar during cooling. This imbalance interferes with the sealing process.
Liquid levels: Air bubbles take up space. When there’s trapped air between your food pieces before sealing the jars, the liquid level in the jar drops when the food is heated. (For releasing air bubbles, see Figure 3-3.) In addition, floating and discolored food results from packing your food without the proper amount of liquid in the jars. Snuggly packed food eliminates air and allows enough liquid to completely cover the food with proper headspace (refer to Figure 3-2).
Never skip the step of releasing air bubbles.
Choosing the right canning method and following proper procedures
Always use the correct processing method for your food. Process all high-acid and pickled food in a water-bath canner. Process all low-acid food in a pressure canner. To find out how to determine whether a food has a low or high acidity level, head to the next section. (You can find out about the different canning methods in Chapters 4 and 9.) In addition to choosing the right canning method, follow these steps to guard against food spoilage:
Figure 3-3: Releasing air bubbles from your filled jars.
Don’t experiment or take shortcuts. Use only tested, approved methods.
Never use an outdated recipe. Look for a newer version. Do not update the directions yourself. Check the publishing date at the beginning of the recipe book. If it is more than 5 years old, find a newer version.
If your elevation is higher than 1,000 feet above sea level, make the proper adjustments in processing time and pressure for your altitude. See the section “Adjusting your altitude” for information on altitudes and processing times.
If you’re pressure canning, allow your pressure canner to depressurize to 0 pounds pressure naturally; don’t take the lid off to accelerate the process.
Allow your processed jars to cool undisturbed at room temperature.
Process your filled jars for the correct amount of time and, if you’re pressure canning, at the correct pressure (both will be stated in your recipe). Make adjustments to your processing time and pressure for altitudes over 1,000 feet above sea level.
Test each jar’s seal and remove the screw band before storing your food.
Checking your equipment
To prevent spoilage, your equipment must be in good shape and working properly:
Have the pressure gauge and seal on your pressure canner tested every year for accuracy. (Weighted gauges don’t require testing.) This is often offered for free at your local extension office.
Use jars and two-piece caps made for home-canning. Discard any jars that are cracked or nicked.
Never use sealing lids a second time. Always use new lids. The sealant on the underside of the lid is good for only one processing. If your jars do not seal the first time, always replace the lid with a fresh one. There may be a problem with the sealant, despite starting with a new lid.
Knowing the Acidity Level of Your Food
Knowing the acidity level of the food you’re processing is important because the pH, the measure of acidity, determines which canning method you use: water-bath or pressure canning. For canning purposes, food is divided into two categories based on the amount of acid the food registers:
High-acid foods include fruits and pickled foods. (For detailed information on identifying and processing high-acid food, refer to Chapter 4.) Foods in this group have a pH of 4.6 or lower. Processing them in a water-bath canner destroys harmful microorganisms.
Tomatoes are considered a low-high acid food. With all of the new varieties of tomatoes, it is now recommended that the home canner add an acid to the canning process, to ensure that the proper acidity is reached every time.
Low-acid foods, primarily vegetables, meat, poultry, and fish, contain little natural acid. Their pH level is higher than 4.6. (Check out Chapter 9 for detailed information on identifying and processing low-acid food.) Process these foods in a pressure canner, which superheats your food and destroys the more heat-resistant bacteria, like botulism.
If you want to feel like you’re back in science class all over again, you can buy litmus paper at teacher- or scientific-supply stores and test the acidity level of your food yourself. Also referred to as pH paper, litmus paper is an acid-sensitive paper that measures the acid in food. When you insert a strip of pH paper into your prepared food, the paper changes color. You then compare the wet strip to the pH chart of colors that accompanies the litmus paper.
The pH, or potential of hydrogen, is the measure of acidity or alkalinity in food. The values range from 1 to 14. Neutral is 7. Lower values are more acidic, while higher values are more alkaline. The lower the pH value in your food, the more acidic it is.
Avoiding Spoilage
Food spoilage is the unwanted deterioration in canned or preserved food that makes your food unsafe for eating. Ingesting spoiled food causes a wide range of ailments, depending on the type of spoilage and the amount of food consumed. Symptoms vary from mild, flulike aches and pains to more-serious illnesses or even death.
But having said that, the potential for spoiled food shouldn’t stop you from canning. When you understand the workings of these microscopic organisms and enzymes, you’ll know why using the correct processing method for the correct amount of time destroys these potentially dangerous food spoilers. And you’ll have nothing to worry about.
Meeting the spoilers
Mold, yeast, bacteria, and enzymes are the four spoilers. Microorganisms (mold, yeast, and bacteria) are independent organisms of microscopic size. Enzymes are proteins that exist in plants and animals. When any one or more of the spoilers have a suitable environment, they grow rapidly and divide or reproduce every 10 to 30 minutes! With this high-speed development, it’s obvious how quickly food can spoil. Some of these create spoilage that can’t be see
n with the naked eye (like botulism), while others (like mold) make their presence known visually.
Living microorganisms are all around — in your home, in the soil, and even in the air you breathe. Sometimes microorganisms are added to food to achieve a fermented product, like beer or bread (for leavening). They’re also important for making antibiotics. The point? Not all microorganisms are bad, just the ones that cause disease and food spoilage.
Canning and Preserving For Dummies Page 5