Pressure Canning Instructions

Pressure canning is a cheap and safe method for home-preservation of low acid foods which is used especially by home gardeners and people wanting to store food whilst quality controlling the contents. This is the only process which is recommended by the United States Department of Agriculture, Washington DC for the canning of these low acid foods including meat, poultry, vegetables and seafood.

Another option is boiling water but this method of processing is only suitable for some foods.

Invisible micro-organisms are all around us but they are not an issue unless food is left out for prolonged periods of time.

There are four specific types of spoilage organisms, three of which are enzymes, moulds and yeast.

Boiling water at 212 degrees Fahrenheit is sufficient to destroy these agents but to kill the fourth type, which is harmful bacteria especially clostridium botulinum, a temperature of at least 240 degrees F is required.

Obliterating all of these types is very important as if they remain, enzymes will reduce the quality of your food, unchecked mould will spread through large quantities of food and yeast will cause fermentation which will render food inedible.

Bacteria spoilage has four categories:

Fermentation which causes food to go sour due to a an amalgamation of gas and acid
Flat sour which is when there is no gas but there is acid formation
Putrefaction, whereby there is gas, bad odour and possible darkening of food and
Toxins and poisons, which may not even be visible unless one of the other spoilage organisms are also present.

To protect yourself from using canned foods which may possibly be affected with spoilage, you need to heat all low-acid meats and vegetables to 15 pound pressure prior to consumption.

When pressure canning in a pressure cooker, the boiling water creates steam and after all of the air is released out of the vent, the increasing steam closes the air vent/cover lock and this, in turn, creates pressure.

As this pressure builds, temperatures within the pressure cooker reach 250 degrees F. (15 pounds pressure).

Pressure Canning Instructions

You can canning in pressure cooker as long as you keep these 2 in mind:

Do not use pressure cooker for canning over 3000 ft altitude
And read the manual of your pressure cooker. Look for pressure canning instructions. I am sure different brands has different instructions on how to can. Make sure you follow them.

And here is the instructions I found in presto pressure cooker.

To pressure can, place the canned food inside the pressure cooker and lock the cover shut.

Place the pressure regulator weight on the stem and once it has reached 15 pound pressure, remove from the heat and allow the pressure to drop naturally.

You can also check if food has spoiled by emptying canned food into a pot and boiling for 10 to 15 minutes before tasting or using.

This heating will allow you to detect any unusual smells or textures which you would not otherwise notice when the foodstuff is cold.

All of these instructions below are for canning at pounds pressure using 6 quart pressure canner (I use it on presto pressure cooker)

Canning Vegetables

If you are planning on canning vegetables, it is best to use freshly picked produce rather than overripe ones because the more it is left to stand, the more the fresh flavour, smell and colour is lost.

Also, try not to bruise vegetables as spoilage organisms grow quicker on bruised vegetables.

Wash and prepare the vegetables as though you are cooking them.

If the vegetable is raw pack them into clean jars, cover with boiling water and cook until they are heated through.

If it is precooked, pack into clean jars leaving an inch space at the top of the jar.

If required, add ½ teaspoon canning salt to each pint jar – table salt is not suitable as it contains an additive which causes cloudiness in the bottom of jars.

Then cover vegetables with boiling water, ensuring that an inch head space is left unoccupied.

If possible, for this water, use the water that you used to boil the vegetables in as it holds the nutrients that the vegetable released although avoid using turnip, kale, greens and asparagus water because this can be bitter.

Close the cap in accordance to the manufacturer’s advice and then place boiling water, cooling rack and jars into the cooker as per the cookers instructions. Close the cooker lid securely but do not add the regulator weight just yet. Put on high heat so that any air can be expelled and allow steam to flow for five minutes before placing the pressure regulator on the vent stem. Then continue heating until it reaches 15 pound pressure.

Pressure Canning Meat and Poultry

Cut meat or poultry into small uniform pieces and then precook either by boiling, frying or roasting. Precook meat until its turns light brown and poultry until it is medium done.

If you are boiling, make a broth using the bones and trimmings and whilst still boiling add the cuts of meat or poultry.

Do not use flour to brown or make gravy to pour over meat.

Lightly pack the hot meat or poultry into clean jars leaving an inch head space and being careful not to pack it in tightly.

Canning salt may be added as before or it may be added when serving.

Pour in hot liquid broth, meat juice or water ensuring that you leave the 1 inch gap. Then close the jar lids and place in pressure cooker as above.

Canning Seafood and Fish

When canning fish, you need to buy good quality fresh fish that has been bled and thoroughly cleaned of the innards as soon as possible to when it is caught.

Pressure Canning Whole Clams (Littleneck)

Scrub the clams clean and leave to soak overnight in 10% brine. Open the clams and use a salt solution, 1 tablespoon salt per quart of water, to wash them.

Add 1/8 teaspoon of citric acid per quart of boiling water and pour this water over the clam meat enough to cover it.

Allow to stand for one minute and then pack loosely into clean, hot Mason jars leaving an inch up top.

Add ¾ inch of hot concentrated clam juice and cover with lid.