Before the refrigeration method was widely used, people used to balance their food supply between lean and harvest times by storing excess food for later use. One of the food preservation methods used is canning. While most foods can only be safely canned under the high temperatures and pressures that require a pressure canner, many acidic foods (pH less than 4.6) can be preserved in jars simply by boiling/immersion in boiling water.
The basic principle of canning is to kill all microorganisms that can spoil food, then close the can or jar tightly and tightly to prevent bacteria from entering. That's why the cannery places great emphasis on sterilization, sanitation, and hygiene. Here are the steps for how to canned food properly.
Step
Method 1 of 6: Choosing Foods to Canned
Step 1. Choose what foods you will canning
The best thing is canning the food you like. There's no point in canning large quantities of food if you or your family don't like it and won't eat it unless you plan to sell it or give it to someone else.
If you grow your own fruits and vegetables, choose foods that you have in abundance. If your peach tree is bearing very heavy fruit this year, then canned peaches instead of the two strawberries you harvested this season. Canning is a great way to preserve tomatoes or apples in peak season
Step 2. Start with something simple if you've never canned before
Some foods require more handling, time, and processing steps than others.
If you're just getting started canning, start with a batch of tomatoes or jam instead of 18 pounds of apples. You'll be able to can more later once you're comfortable and familiar with the process and like it. Remember, although cherries can be canned, you must first remove the seeds
Step 3. Choose foods that are in good condition
Fruits and vegetables should be firm or firm and ripe, and free of spots and mildew. Food doesn't have to be pretty to be canned. If you're growing or buying tomatoes, you may want to use "processed tomatoes" (those with more ridges and seams) or pickled cucumbers.
Method 2 of 6: Preparing Food for Canning
Step 1. Check out the latest canning recipes and guides (see tips and resources) for the right canning techniques and times for the foods you choose
Different foods require different processing processes. You can use your family's old favorite recipe, but still compare it to similar recipes in the latest guide and adjust processing times and techniques accordingly. The basic safety precautions and precautions may have changed since the old recipe was written.
Check the latest USDA guidelines or Ball or Kerr's book for a canning length that suits the contents and size of the jar, especially if you're using an older recipe. Processing times have changed over the years as we have learned more about food safety and, in some cases, because food is being cultivated in different ways. Tomatoes, for example, may now be much less acidic than they used to be
Step 2. Wash your hands thoroughly and keep them clean during the handling process
You want to reduce the amount of bacteria that can contaminate your canned food as little as possible. Wash your hands again before resuming work if you sneeze, use the bathroom, or touch non-food items during the process.
Step 3. Prepare the food according to the recipe
Most foods need to be cut so they can fit into the jar more easily.
- Peel and chop fruit or vegetables. Note that you can "peel" certain fruits. Peel the peaches, nectarines, and tomatoes by briefly dipping them in boiling water until the skins split open. Then, use a sieve to scoop it out and place it in cold water. Once the fruit is cool enough to handle, peel off the skin immediately.
- Remove the pits, stems, center 'bones', and other uneaten parts of the fruit. Note that 'freestone' peaches are peaches whose seeds are easy to remove, while other types of peaches tend to have the seeds attached to the flesh. Choose the one that suits you.
- Cook jam.
- Cook and/or soak pickles.
- Prepare sauces, applesauce, butter, and other foods according to individual recipes.
Step 4. Make a liquid marinade for packaging in cans if your recipe calls for it
Most fruits and vegetables are usually canned in syrup (a mixture of water or juice and sugar) or a saline solution (a mixture of water and salt). Refer to the specific recipe for the food you want to canned to see which liquid is needed.
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Basic recipe for canning syrup: For a light syrup, bring 6 cups water and 2 cups sugar to a boil. This will make 7 cups of syrup. For medium syrup, bring 6 cups water and 3 cups sugar to a boil. This will make 6 cups of syrup. For a 'heavy' syrup (which is even sweeter and has a high sugar content), bring 6 cups water and 4 cups sugar to a boil. This will make 7 cups of syrup.
Sugar can be replaced with a low-calorie sweetener brand Splenda or Stevia, but do not use Nutrasweet
- Base mixture for pickle sauce: Place 5 cups vinegar, 1 cup water, 4 teaspoons (20g) pickle salt, 2 tablespoons (28g) sugar and 2 cloves of garlic (optional but will add flavor) to a saucepan and bring to a boil. Once it boils, reduce the heat until the liquid boils slowly for 10 minutes. Take and discard the garlic cloves after the mixture simmers gently for 10 minutes. 1 cup = 240 ml.
Method 3 of 6: Jar Bottle Sterilization
Step 1. Sterilize the jars that you will use for canning by boiling them in water for 10 minutes
It is important to sterilize bottles because if there are bacteria in them when you fill the bottle and then close it, the food inside could rot. If you are at high altitude, add an additional 1 minute for every 1,000 feet (304.8 m) above sea level. Once sterilized, place the bottle upside down on a clean towel and cover with 1 more towel on top until you're ready to use it.
You can also sterilize jars by placing them in the dishwasher. Run the dishwasher for a full wash cycle
Step 2. Boil 2.5 cm of water in a medium saucepan
Remove the pan from the heat. Put the cap of the jar in the water. Push the lids down so they sink, and try not to stack them on top of each other so the lids can get an even heat. Let the lid soften for a minute or two. You can do this while you're filling the jar and wiping the lip of the bottle, if you're timing it right.
Method 4 of 6: Canning the Food You Choose
Step 1. Fill the jar
This step is also called packing the jar bottles. Foods are called "hot-packed" or "cold-packed" depending on whether they are pre-cooked and then bottled hot or simply sliced and bottled chilled. These differences can affect the cooking time for the same type of food, so be sure to read the recipe carefully.
- A funnel for bottles will make this step easier, especially for small pieces of food and liquid or semi-liquid foods.
- For individual foods such as string beans, arrange them in jars. Do this as neatly as you want. If you will be displaying jars at a show, you may want to pack them very neatly. On the other hand, if you're only going to put it in your soup for later use, you probably don't have to worry about arranging it neatly and perfectly.
Step 2. Leave a little free space at the top
This free space is required and the height varies between about 3 mm - 25 mm depending on the type of food, so refer to the specific instructions for the food you are canning.
Step 3. Add preservatives according to the recipe
Preservatives used in home canning include sugar, salt, and acids such as lemon juice, and ascorbic acid (better known as Vitamin C) which is commonly sold in powder form with other canning supplies. Add the preservative before adding the liquid, so it will help mix it up as you pour the liquid over it.
Step 4. Pour syrup, pickle sauce, or other type of pickling liquid into the bottle
Leave 1.27cm of free space at the top of the jar.
Step 5. Remove air bubbles
When you pour the liquid over the loosely arranged pieces, you will leave air bubbles. Remove these bubbles by running a long plastic knife (also available with the canning kit) down the side of the jar and shaking or gently pressing the food.
Step 6. Wipe the top of the mouth of the bottle and between the parts for the bottle cap using a clean, damp cloth to remove any food residue or drips
In particular, be sure to clean the lip of the bottle where the cap will be placed later.
Step 7. Place the softened seal on each jar
You can use a magnetic cap stick to help you safely lift the lid of the jar out of the boiling water. To remove the cap, place the cap over the jar and tilt the wand.
If you don't have a jar lid lifting wand, you can use small tongs instead. But don't touch the lid by hand
Step 8. Screw the clean ring under the seal and secure it with hand pressure
Don't tighten it so much that you squeeze all of the lid material off the jar.
Method 5 of 6: Using a Canning Tool
Step 1. Use a water-immersed canner if your canning recipe calls for it
Canning by immersion in water can be used for many cooked foods (sauces, pickles, jams) and sour fruits (sauce, peaches, pears, apricots). Check current recipes to make sure the canning soak in water is sufficient for your food.
Lower the jars onto a rack in an immersion canner or large saucepan. Add enough water to submerge the jar until the water is 2.5-5 cm above it. Remember to add hot water only if the food in the jar is hot, and add cold water if the food is cold. Avoid putting the jar in contact with sudden drastic changes in temperature. You can measure it with your first knuckle, as shown. Do not pile jar bottles in the soaking canner
Step 2. If you are using a large pot, place a shelf or other barrier (such as a small towel) at the bottom of the pot so that the jars don't place directly on the bottom of the pan
Cover the canner or pot and heat the water to a slow boil. Simmer for the specified time, increase the heating time if you are at an altitude of more than 914.4 m above sea level
Step 3. Use a pressure canner if your recipe calls for it
Pressure canners need to be used for canning meat and most vegetables because these ingredients don't have enough acid in them, which can act as natural preservatives. Canners can also reduce processing time for foods such as peaches and tomatoes, compared to regular soaking canning. To prevent the growth of certain harmful bacteria, it is necessary to process low-acid foods at higher pressures. A pressurized canner will raise the temperature by accumulating the pressure inside. Usually, it is necessary to raise the temperature to 116C to kill harmful types of bacteria.
- Arrange bottles in a pressure canner. For small jars, you may be able to stack them, as long as they are balanced. That is, don't place another jar directly on top of the jar lid below it so that it stands straight, but place the jar on top of the rim of some other jars, so that the jar is supported by several jars and the bottom has an empty space.
- Check the rubber gaskets before you start the pressure canning process each year. Gaskets tend to dry out if they are left on the shelf for a long time. The gasket must be able to form a seal on the bottle. You may be able to loosen a slightly dry rubber gasket by submerging it in just boiling water. If your gasket is too old or cracked, replace it. You should replace your gaskets every year or two.
- Place the pressure canner cap in place and twist it until the appliance is tightly closed. Often the position of the handle will indicate that the tool is closed. Remove the valve from the canner lid.
- Heat the pressure canner until it boils. Pay attention to the steam escaping from the valve opening. Usually there is also an indicator pin in the middle. This pin will explode as steam accumulates in the canner.
- Let the steam out for some time. When steam gushes out with a strong and even (straight) flow, it is called a "full head of steam". Allow the canner to fully steam for seven minutes or according to the canner's recipe or instructions.
- Place the valve on the vent and start the specified canning time. The needle on the pressure gauge will begin to rise.
- Adjust the temperature on the stove so that the pressure in the canner is as directed in your recipe, and adjusted to the height. #*The pressure is usually 10 psi at sea level. Usually you have to make some adjustments to get the pressure right. It will take some time to see the effect of each adjustment on the pressure gauge because the pot is full of water and the jar needs to be changed before the needle shows any change.
- Supervise the pressure canner throughout the process, and adjust the heat as necessary. Airflow and other variations will cause the pressure to constantly change. Lower the heat a little if the pressure is too high and increase the heat if the pressure drops. Don't assume that you've reached a point of balance, as airflow and other variations can upset the pressure pretty quickly. Too low a pressure can fail to cook to a sufficient temperature; Too high a pressure can cause the jar to break.
- Process the jar for the full time as specified in the recipe, after that turn off the heat, leave the valve in place until the indicator pin drops. When the pin drops, remove the valve and allow the canner to release the pressure and steam for a few minutes.
- Open the lid of the tool slowly and hold it for a few moments. You can even leave the lid slightly ajar for a minute or so. This doesn't happen very often (especially if you're careful to gradually reduce the pressure), but the jars in pressure canners sometimes break when the pressure is released.
Method 6 of 6: Processed Jar Bottle Handling
Step 1. Remove the jar from the canner
Using jar tweezers is a safe way to do this, or you may be able to raise the holding basket all at once. Place the jar on a clean washcloth and let it cool.
Step 2. Let the jars cool for 24 hours in a place free from drafts
You may hear the metal lid creaking loudly. This is simply caused by the contents of the jar starting to cool and creating a partial vacuum in the jar. Don't touch the lid just yet. Allow the jar and cap to seal on their own.
Step 3. Check to make sure that the jar is sealed after a few hours
The vacuum condition caused by the cooling contents will cause the center of the lid to bend slightly. If you can press the center of the bottom lid, it means it's not sealed. The section should not come back up. If any jars are not sealed yet, you can place a new cap on the jar and process it in a pressure canner again, or refrigerate it and use the contents right away.
Step 4. Wash the jars with soapy water at room temperature to remove any food residue on the outside of the jars
You can remove the ring first at this stage, as the cap should close tightly and securely even without the ring. Allow the rings and jars to dry completely before placing the rings back in to prevent rust.
Step 5. Label the food in your jar with the year of canning, at a minimum
Also consider writing down what's inside because apples and peaches can be hard to tell apart a month later. Write your name too, if you are giving this jar as a gift. You can use permanent stickers or markers.
Label your jars on the lids instead of the glass bottles if you want to easily reuse the jars. Store jars on shelves, and avoid exposure to excessive heat or light. Chill in the refrigerator after opening and the contents are still left
Tips
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Take notes. You may not remember well in later years what you did in the canning process and how it turned out. The notebook that comes with the canning kit will remind you of this and can help with your next canning process. Write down the following:
- How many raw materials and how many jars of each size are produced.
- How many jars do you can and how many does your family use each year.
- The canning technique or recipe you found.
- Where do you buy the food you use and how much you buy it.
- The ring and glass bottle are reusable. Jar bottle caps must be replaced because the cap material may deform after use. Remove rings that are dented or too rusty.
- Eat what you can. Don't just leave it on the shelf and admire how much work you've done. Homemade canned food has a limited shelf life, so eat the contents within the first few years. Otherwise, what's the point?
- If you are reusing an old bottle, check for cracks. Run your finger slowly around the mouth of the jar to make sure it's smooth and undamaged.
- Depending on your stove, you may want to use a stove or a special heater for canners. Canning hobs have a pot holder that is slightly higher than the surface of the hob to prevent too much heat from accumulating under very large canning pans.
- If there are a few jars left at the end of the batch, you can add them to the next batch (fill the fruit first), place in small jars, or refrigerate and use immediately. This is a great opportunity to taste your hard work.
- If you are buying food that you will be canning in bulk, ask the seller if you can order and get it for less.
Warning
- Homemade canned food can cause deadly disease if spoiled or handled incorrectly. Always process food for the recommended length of time, clean and sterilize jars properly before use, and dispose of food in unsealed jars. Also throw away any jars whose contents smell bad or strange, or look moldy or discolored.
- Open-boiler canning, the once popular method of sealing jars by turning the jars upside down so that the hot contents of the jars create a seal, is not considered safe. The paraffin method is also questionable. It is best to use a metal cap and process the jar for the recommended time in boiling water.
- While you may have jars of food products you've purchased that fit the ring of canning jars, real canning jars are the best. These jars are designed with glass thick enough to withstand repeated processing and home canning. You can use these used jars to store dry spices or your coin collection.
- Avoid placing cold glass cups in hot water or vice versa. Sudden changes in temperature can make the glass shatter.
- Do not use mayonnaise bottles or other jars that are not mason jars for pressure canning.
What you need
Gather the right equipment. Some items can be improvised and some cannot. Don't let this long list scare you. These items should already be in a fully equipped kitchen:
- Big pan
- Apron
- Big spoon
- Good quality cutting knife and paring knife
- Bowls and spoons as needed
- Ladle
- Filter container
- Wipe old but clean clean towels, so it's not a shame if it's dirty
- Kitchen stopwatch
- Container and dish soap
- Duster
- Filter
Basic canning needs:
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mason jar
- Choose the right size: liter, 340 g, liter, 567 g or 737 g, and 1 liter. 1/2 gallon and cup bottles are also available, but these are not great for beginners. Half gallon jars may take a very long time to process, even if these volume jars are listed in your canning recipe. The cup jar can be difficult to close continuously.
- Distinguish between wide-mouthed and regular (regular) jars. Both have different sizes of caps and seals. Wide-mouthed jars make it easier to pack food in large chunks such as halved pears.
- Mason jar ring and cap. New jars usually come with this, or they can be purchased separately.
- Jar bottle clamp (to safely remove heat from boiling water).
- Magnetic wand to lift the bottle cap, jar or small clamp.
- A canning container with soaking water or a large saucepan.
Get the following items when and when you need them:
- Pressure canner (pressure canner)
- Hot diffuser wire
- Filter bag (jelly bag) and the support
- Thin filter cloth
- Bubble knife
- Ricer (a tool such as a small manual food processor for mashing cooked potatoes and removing them through small holes so that they resemble rice grains)
- pressure cooker
