canning

Pressure Canning – basic principles

Posted on September 14, 2011 at 7:20 am

If you want to know how to preserve food by pressure canning, this article is what you need. You may want to check out my boiling water bath article as well.

First, what foods must you pressure can? Low-acid foods. In this context, low acid is defined as “pH 4.7 or higher”. Vegetables, meat, fish, stocks, and finished foods like stews or soups all need to be pressure canned. Tomatoes are a special case as they are right on the cusp of pH 4.6, so they can be canned using either the boiling water bath method (with added acid like lemon juice or citric acid) or by using pressure.

Second, what is a pressure canner? Can I just use my pressure cooker?

Pressure canner and jiggle weight

Pressure canner and jiggle weight ( jiggle weight is the column to right of pressure gauge with ring either side)

The simple answer is “no”. Most domestic pressure cookers are not rated or constructed to take the sustained pressures for which a pressure canner is designed. When processing beans with my easy prepare method, for example, I am canning at 10psi for 90 minutes. Unless your pressure cooker specifically states it is rated for pressure canning, it is not suited to this task. Canners like the Presto 23qt canner I have (see picture) cost around $80 and are a worthwhile investment – you can use it as a pressure cooker, pressure canner, AND as a boiling water bath canner.

A note on pressure canner gauges. If you intend using the pressure gauge, you must get the gauge checked for accuracy every year. This is a free service by most county extension services in the USA. I use a jiggle weight because I can always tell when the canner is at the right pressure – I listen for the “pshht pshht” noise of the jiggle.

Third, you need lids and bands. New jars come with lids and bands, but you should pick up extra lids when you can get them at a good price. The bands are reusable for many canning sessions – they only need to be discarded if they show signs of rust or corrosion.

And finally, you need something to put in the jars – the “jar contents”.

PREPARATION STEPS

If you’ve already read my article on boiling water canning you already know the first few preparation steps, and can skip down to Putting on the squeeze.

JARS
To start a pressure canning session, first clean the jars you are going to use. Running them through the dishwasher works well; if you don’t have a dishwasher you can wash them in the sink. Once they have been cleaned, put them in the canner, fill the canner with hot tap water to the appropriate fill line marked on the inside of the canner (see your canner’s instruction sheet) and put a little hot tap water into the jars to keep them from falling over. Once the jars are resting in the hot tap water, put the lid on the canner to retain heat, put the canner on the hob, and set it to a medium-low temperature.

This is all before you do anything to the “jar contents”. You are aiming to have the jars at a good hot temperature before filling them with the “jar contents” – too much of a temperature difference between the jar and the contents leads to thermal shock, also known as “glass shrapnel and incendiary contents spread across the kitchen”. Thermal shock is generally considered A Bad Thing(TM) and is definitely to be avoided.

Once the “jar contents” are starting to cook, increase the heat under the canner with the aim of getting it to a boil once the “jar contents” are ready. It’ll take you a little practice to know exactly when to turn the heat up, but don’t sweat it too much – you can keep the “jar contents” nicely hot for a few extra minutes if needed, and it doesn’t really matter if the empty jars are heating for longer than needed.

LIDS
Give the lids a good clean with plenty of soap and hot tap water and then rinse thoroughly. I have seen many people saying to boil the lids and then keep them in the hot water straight after boiling, but according to the Ball Complete Book of Home Preserving (which I cannot recommend strongly enough – it is absolutely essential for a home canner), all that is needed is to keep them to a simmer – 180F/82C.

Once your lids and jars are ready, you can ladle in your jar contents (the soup, stock, stew, beans, etc.) and then seal the jars.

SEALING THE JARS
Once each jar is filled to the appropriate level (usually within 1/2 to 1 inch of the top of the jar depending on the recipe) you should wipe off the rim of the jar to make sure that there is nothing on the rim to interfere with a proper seal. Use a paper towel sprayed with a 50/50 mix of white vinegar and water to wipe off the rim. Lift lids out one by one and place on the rim. Screw down the bands to “finger tight”: use your fingertips to screw the lid down until you can’t tighten it any more, but do not tighten the lid as tight as you possibly can. The purpose of this step is to secure the lid on, not to seal it completely – there needs to be a little looseness in the band to allow air to escape, but equally you don’t want water to get into the jar. The jar seal comes from the vacuum you will create in the water bath stage.

PUTTING ON THE SQUEEZE
Once your jars, lids, and “jar contents” are ready, it’s time to put them into the canner on the rack at the bottom.

Place the lid on the canner, bring the canner to a full boil, and vent the canner for 10 minutes. Count the 10 minutes from when the stream of steam is running full blast – on my canner I get a whistling noise at this point. You can tell that the appropriate point is reached when the steam is a solid column – this is when you start your timer.

Once the 10 minute vent is completed, put the weight on the vent and process for the amount of time specified in the recipe. Once the processing time is up, take the pot off the heat and walk away. You need to let the pressure canner return to normal pressure. This will take a variable amount of time, but you cannot hurry this step – remember thermal shock! Once the pressure gauge has dropped to normal, leave the canner for an additional 10 minutes then take the lid off the canner. Use your jar lifter or tongs to take the jars out of the hot water to cool.

COOLING THE JARS WITHOUT THERMAL SHOCK
The best way I have found to cool jars without having any danger of thermal shock (hot jars and cool countertops do not mix) is to use a cookie rack. This allows free air circulation around the jars without putting them onto any surface which could turn them into bombs.

Leave the jars overnight; the next day you can take the screw bands off and test the seal.

TESTING THE SEAL
Testing the seal is easy. If you can lift the jar up by the lid, the seal is good. If you can’t, the seal is bad! If a jar didn’t seal properly, treat it as an eating jar and just finish the contents within a few days or freeze the jar and its contents for later use.

RULE OF THUMB
The rule of thumb when calculating how long to pressure can for: look up each ingredient on the USDA list separately. Note the longest time any single ingredient requires. Pressure can for that amount of time – the longest amount of time required by any single ingredient.

You were waiting for me to say what the jar contents are? Well… that’s up to you. Go for it!

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Boiling Water Bath Canning – basic principles

Posted on August 14, 2011 at 5:07 pm

This article should serve as a handy reference point for anyone who is unsure how to can by using the Boiling Water Bath, or Hot Water Bath, method. You might want to have a read of my article on setup costs as well.

The technique I am describing here is only for products that can be dealt with in a hot water bath process, or “high acid foods”. A few examples of high acid foods are jams, jellies, pickles, relishes, and chutneys. Foods such as vegetables, meat, fish, stocks and broths are “low acid foods” and need to be dealt with by pressure canning, which I will deal with in a separate article.

First, you need a boiling water bath canner:

canner with jars

Canner and jars

Next you need some jars. Exactly what size you use will vary depending on recipe. Jelly jars hold 1 cup(8 US fl oz)/250ml (centre of rack in picture above). Pint jars hold 2 cups/500ml (centre left and right of rack in picture above). Quart jars hold 4 cups/1 litre (back of the rack in picture above). I know that these are not exact conversions of US fl oz to ml, but the volume difference between the metric and American style jars doesn’t make any difference for our purposes – the recipes and the processing times are the same.

Third, you need lids and bands. New jars come with lids and bands, but you should pick up extra lids when you can get them at a good price. The bands are reusable for many canning sessions – they only need to be discarded if they show signs of rust or corrosion.

And finally, you need something to put in the jars – the “jar contents”.

PREPARATION STEPS

JARS
To start a boiling water bath session, first clean the jars you are going to use. Running them through the dishwasher works well; if you don’t have a dishwasher you can wash them in the sink. Once they have been cleaned, put them in the rack, place the rack in the canner, then fill the canner with hot water (from the tap is fine) until the jars are covered to about a finger width above the rims. Once the jars are covered with hot tap water, put the lid on the canner, put the canner on the hob, and set it to a medium-low temperature.

This is all before you do anything to the “jar contents”. You are aiming to have the jars at a good hot temperature before filling them with the “jar contents” – too much of a temperature difference between the jar and the contents leads to thermal shock, also known as “glass shrapnel and incendiary contents spread across the kitchen”. Thermal shock is generally considered A Bad Thing(TM) and is definitely to be avoided.

Once the “jar contents” are starting to cook, increase the heat under the canner with the aim of getting it to a full boil once the “jar contents” are ready. It’ll take you a little practice to know exactly when to turn the heat up, but don’t sweat it too much – you can keep the “jar contents” nicely hot for a few extra minutes if needed, and it doesn’t really matter if the empty jars are boiling for longer than needed.

LIDS
Give the lids a good clean with plenty of soap and hot tap water and then rinse thoroughly. I have seen many people saying to boil the lids and then keep them in the hot water straight after boiling, but according to the Ball Complete Book of Home Preserving (which I cannot recommend strongly enough – it is absolutely essential for a home canner), all that is needed is to keep them to a simmer – 180F/82C.

Once your lids and jars are ready, you can ladle in your jar contents (the pickles, jam, relish, etc.) and then seal the jars.

SEALING THE JARS
Once each jar is filled to the appropriate level (usually within 1/4 to 1/2 inch of the top of the jar depending on the recipe) you should wipe off the rim of the jar to make sure that there is nothing on the rim to interfere with a proper seal. Use a paper towel sprayed with a 50/50 mix of white vinegar and water to wipe off the rim. Lift lids out one by one and place on the rim. Screw down the bands to “finger tight”: use your fingertips to screw the lid down until you can’t tighten it any more, but do not tighten the lid as tight as you possibly can. The purpose of this step is to secure the lid on, not to seal it completely – there needs to be a little looseness in the band to allow air to escape, but equally you don’t want water to get into the jar. The jar seal comes from the vacuum you will create in the water bath stage.

HOT WATER BATH
Once your jars, lids, and “jar contents” are ready, it’s time to put them on the wire rack and lower them into the hot water, which should be at a boil at this stage. You want to see a stream of bubbles come up from the jars.

Place the lid on the canner, and process for the amount of time specified in the recipe. Once the processing time is up, take the pot off the heat, take the lid off the canner (carefully! you don’t want to get caught by the steam!) and leave for 5 minutes before lifting the rack out of the hot water and hooking it over the edge of the canner. Use your jar lifter or tongs to take the jars out of the hot water to cool.

COOLING THE JARS
The best way I have found to cool jars without having any danger of thermal shock (hot jars and cool countertops do not mix) is to use a cookie rack. This allows free air circulation around the jars without putting them onto any surface which could turn them into jam bombs.

Leave the jars overnight; the next day you can take the screw bands off and test the seal.

TESTING THE SEAL
Testing the seal is easy. If you can lift the jar up by the lid, the seal is good. If you can’t, the seal is bad! If a jar didn’t seal properly, treat it as an eating jar and just finish the contents within a few days, or as normal (pickles last longer than jams when opened).

You were waiting for me to say what the jar contents are? Well… that’s up to you. Go for it!

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Pluot Jam

Posted on August 7, 2011 at 12:17 pm

I am in the lucky position where the farmer’s market comes to our office once a week. This is a great way to get people to eat more fruit and veg (put it right in front of them!) so I bought some pluots* and proceeded to make jam with them!

4 pints of sorted, scrubbed, and chopped pluots – about 3lbs
1/4 cup lemon juice – fresh squeezed or bottled
1/2 cup Water
5 cups white sugar
1 packet pectin
1/2 teaspoon vegetable oil (I use plain olive oil – not the extra virgin stuff)

Put the chopped pluots in the pot with the water, lemon juice, pectin, and sugar. Heat gently while stirring vigorously to ensure the pectin is completely incorporated into the mix.

Once the pectin is fully incorporated, apply medium-high heat while stirring frequently until the mixture comes to a full, rolling boil – a boil that cannot be stirred down. Keep boiling and stirring for at least 1 minute then take off the heat. If there is a lot of foam stir in the 1/2 teaspoon of vegetable oil and allow to rest for 5 minutes.

Once the 5 minutes is up, stir the mixture, jar, lid, ring, and boiling water bath process for 10 minutes, Yield: 8 to 10 jelly jars (1/2 pint).

* pluot: hybrid between a plum and an apricot

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Blueberry fruit butter

Posted on July 29, 2011 at 7:32 am

Fruit butters are extremely easy to make in your slow cooker and you can use any fruit to make a butter. Use this recipe and technique to design your own – substitute your favourite fruit for blueberries.

 

  • Blueberries – 5 pints / 10 cups / 2.25 litres / about 3.5 lbs / about 1.75 kg, preferably fresh
  • Lemon juice – either fresh squeezed or bottled. 1/4 cup.
  • Water – 1/2 cup
  • Sugar – 5 cups
  • Seasoning – 1 teaspoon of ground cinnamon and 1/4 teaspoon of ground cloves

Pick your blueberries or buy them from the store. It’s better to use freshly picked if you can. If using fresh, wash them thoroughly and pick through for mushy berries, twigs, bugs, and the other stuff you don’t want to be eating!

Mash the blueberries as much as you care to – the mashing will affect the cooking time, which isn’t so much of an issue with this method, as well as the texture – I prefer it a little chunky, so I didn’t worry too much about getting the berries reduces to a paste. If you prefer smoother, you could process the berries in a mixer or food processor.

Place the fruit, water, lemon juice, and sugar in your slow cooker. Put the lid on the cooker and prop it open slightly – you can use a spoon, pencil, or splatter guard, whichever you prefer, so long as one corner of the lid is open to allow water to evaporate. Put the cooker on the longest cooking setting and walk away. That’s right – just walk away!

When the cooker stops cooking and switches to “keep warm”, give the fruit butter a stir and check for consistency. If the consistency is what you want, you’re done! If you want a thicker butter, hit the “cook low and slow” button again and walk away. The butter is ready when it’s how you want it to be, which is the beauty of making it yourself.

If you want to put the butter up on the shelf, prepare your jars and lids and hot water bath process for 10 minutes (below 1000ft above sea level, check with USDA guidelines for extra processing time above 1000ft).

Yield – between 2 and 4 cups, or between 4 and 8 jam jars, depending on how thick you like it. I doubled the recipe and cooked it quite thick which gave me a yield of 9 jam jars or 4.5 cups of fruit butter.

You can use this same technique to turn any fruit into a butter. Enjoy!

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Blueberry pie filling

Posted on July 21, 2011 at 8:33 am

Part 2 of my short series on blueberries – pie!

7 cups blueberries, washed and sorted
1 2/3 cups sugar
2/3 cup ClearJel
2tbsp lemon juice

OPTIONAL
12 drops blue food colouring
4 drops red food colouring
1tsp grated lemon zest

Prepare your jars and lids in the usual way.

Half fill a large stainless steel pot with water and bring to a rolling boil. Add blueberries for 1 minute to blanch, drain, then return them to the pot. Cover the pot to keep them warm.

Combine the sugar and ClearJel in a large stainless pot. Whisk in 2 cups / 500ml of water, add food colouring if using, then bring to a boil over medium-high heat, stirring occasionally. Reduce heat and boil gently while stirring until the mixture thickens and begins to bubble. Stir in lemon zest if using, add the lemon juice and cook for 1 minute. Remove from the heat and gently stir in the blueberries and any juice until they are well incorporated into the mixture.

Ladle the pie filling into jars leaving 1 inch / 2.5cm head space. Remove any air bubbles, adjust head space if necessary by adding or removing filling. Wipe the rims of the jars with a paper towel that has been sprayed with white vinegar. Lid, band, and hot water bath process for 30 minutes. At the end of the 30 minutes turn off the heat, remove the lid of the boiling water bath canner and wait for 5 minutes before gently removing the jars to a cookie rack.

Cool on a cookie rack overnight, remove the bands, label the jars, put them in your pantry, and enjoy blueberry pie!

Yield: about 4 pint / 500ml jars.

A note on ClearJel: it’s worth using it instead of any other option. Yes, it’s more expensive than, say, corn starch, but ClearJel is specifically formulated to work with pie fillings – repeated heating does not cause the ClearJel to break down into liquidy mush.

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Blueberry Syrup

Posted on July 19, 2011 at 5:17 pm

Blueberries are in season just now, so get out there and pick some yourself!

Once you have a ridiculous amount of blueberries, what can you do with them? Well, I am here to help with a short series, starting with blueberry syrup.

Prepare your jars and lids by thorough washing with soap and hot water. I also boil the jars for 10 minutes which sterilises them.

6.5 to 7 cups of fresh blueberries, washed and sorted
4.5 to 7 cups of sugar OR 3 cups of natural frozen fruit juice
2 tablespoons lemon juice, fresh or bottled

Mash the blueberries with a hand held masher, food processor, hand blender, or whatever other method you want to use. The hand masher can be very cathartic if you need to work off some stress. Just saying.

Add the lemon juice to the blueberry mush, bring it to a boil and simmer for 5 to 10 minutes – they should be nice and mushy. You now need to make a choice – bits, or no bits? If you want to have a completely smooth syrup with no bits in it, you’ll need to strain the mush with a jelly bag, cheese cloth, or whatever. If you are not bothered about bits, as I am not, you can just move on to the next step.

Add all the sugar in one go. If you need to control added sweeteners, use the fruit juice concentrate instead of table sugar. I added 5 cups of sugar, and am extremely pleased with the result. Bring the blueberry mush and sugar to a boil for about a minute and keep an eye on the texture – you’ll want the syrup to still be a little liquid-y when you put them in the jars as they get some extra cooking time during the hot water processing. Over-cooking at this point could result in a blueberry candy rather than a pourable syrup!

Fill your jars – either pint or half pints – lid, ring, and boiling water bath process for 10 to 15 minutes*. Remove the lid of your BWB processor, wait for 5 minutes, then lift the jars out of the BWB and place the jars on cookie sheets to cool overnight.

Pour over pancakes or waffles and enjoy.

*as usual this is the time for 1000 feet above sea level or less. If you are above 1000ft, please check with the USDA processing guidelines for how much extra time you need to add.

Yield: with 5 cups of sugar I got 4 pint jars, or 8 jelly jars. With 7 cups you should get about 5 pints or 10 jelly jars.

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Easy canning dried beans

Posted on May 17, 2011 at 10:24 am

Canning dry beans can seem like a real pain. The rinsing, sorting, soaking overnight, changing the water rigmarole. There’s the “quick cook” method – boil for 2 minutes, soak in the hot boil water for 1 hour, drain, fresh water, bring back to a boil – pfft, what a pain!

So here’s the super easy way to do it!

Put your pint jars into your pressure canner with hot tap water to the appropriate fill line. Start heating the water with the jars in it. Put your electric kettle on to boil. If you don’t have an electric kettle – why not?!? – boil the water in a pan instead.

Rinse and sort the beans. Put 1/2 to 2/3 cup of rinsed sorted beans in each pint jar, producing an approximate yield of 4 to 5 pint jars from each pound weight of dry beans. Pour in boiling water to 1/2 inch of the top (just about where the screw threads start).

Cap your jars and process at the appropriate pressure for your altitude for 90 minutes. Follow the usual steps for pressure reduction and cooling as specified in your pressure canner user manual.

There you go! Between four and 10 pint jars of pressure canned/cooked beans in about 100 minutes, more or less, ready and waiting for you to deploy them in all sorts of interesting manners.

The beans I canned this way were chickpeas(garbanzo) and pinto beans… you’ll see why later this week.

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Pressure canning – beans

Posted on April 14, 2011 at 2:43 pm

Beans are a powerful ally in living frugally. They have the best “bang for the buck” in terms of nutritional return for money: insoluble and soluble fiber, high in protein, complex carbohydrates, folate, and iron. Once you get a stockpile of dried and canned beans in your pantry you are opening up new vistas of frugal, healthy, and stupidly cheap food.

Start with 2lbs of dry beans – any type, any combination. I started with 1lb of dried black beans and 1lb of dried kidney beans. Sort through the dried beans discarding any that are broken or that are stones masquerading as beans. Wash them in lots of cold water and place them in a large pot with enough water to cover them by 1 inch / 2.5cm. Bring to a boil and boil for 2 minutes. Allow the beans to stand for 1 hour in the hot water.

You now have a choice: discard, or don’t discard, the water. Many recipes recommend discarding the water and starting again with fresh as this reduces the amount of oligosaccharides, which are responsible for the… fragrant!… reputation that beans have. The water also contains trace minerals and nutrients, so I leave it up to you to decide which is more important for you.

Two pounds of dried beans will yield you between 6 and 10 pint jars of ready-to-use beans, depending on which ones you go for. The black/kidney bean mix I did yielded 8 pint jars, at a cost per jar of 25 cents. Most of the cans in the stores are done by weight rather than volume, but they probably contain about 1.5 cups of cooked beans, usually at around 50 cents to over a dollar in price.

Put the squeeze on those bad boys for 75 minutes per pint jar, 90 minutes per quart jar. The National Center For Home Food Preservation is an absolutely essential reference for those of you above 1000ft.

Beans. Full of nutrition. Good for you in multiple different ways. Work well with vegan, vegetarian, and omnivore cuisine. Laughably cheap and stupidly easy to prepare. What more do you need to know?

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Basic meat sauce – pressure canning

Posted on April 2, 2011 at 9:48 am

I like having modular components as well as finished items. What I mean by a “modular component” is something which is not complete in and of itself, but that can very quickly become a tasty meal. In the case of this basic meat cause it can become chilli, curry, spaghetti sauce, or even a pizza topping depending on what spices, seasonings, or other supporting ingredients I add to it.

Basic meat sauce
Ground meat, approximately 3 to 4 lbs (1.5 to 2kg)
6 large (28oz/800g) cans crushed tomatoes

Cook the ground meat (I used beef and venison) with olive or other healthy vegetable/fruit oil until nicely browned. Add the 6 large cans of crushed tomatoes to the meat and heat thoroughly until nice and bubbly.

Portion into quart (litre) jars, leaving 1inch/2.5cm headroom in the jar (fill jar to the point just below where the shoulders narrow) and process in your pressure canner for 70 minutes. Follow the instructions for your pressure canner for time adjustments if you live 1000ft / 300m or more above sea level.

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Seasonal Eating – March

Posted on March 1, 2011 at 8:27 am

Continuing my ongoing series on eating and canning seasonally, what’s new for March?
As the weather is still treacherous, only robust stuff is coming into season. Thankfully there’s more to choose from this month:

* New this month
*Asparagus
Green Cabbage
Fingerling carrots
Peas
Scallions / green / spring onions
*Spinach
Turnip
Greens – turnip and mustard
*Bok Choi
*Swiss Chard
*Onions

Kale
Arugula / Rocket

Going out of season after this month:
Collard Greens

From a canning perspective, a lot of these are not really worth canning (over cooked spinach anyone?), but you can pickle turnips, make onion relish, and freeze others to carry you through to next winter.

PICKLED TURNIPS
Recipe from Ashael Raveh

1.5 kg / 3.3lbs fresh medium turnips
1 small beet
2 stalks of celery
1-2 green chili peppers
0.7l / 3 cups of water
3 teaspoons salt
3 spoons vinegar
Half a teaspoon citric salt (Sodium citrate)
1-2 dry bay leaves
A few whole allspice cloves
Pickle jar with a tight lid – sterilized

Preparation:
Mix all the ingredients but the turnips, celery, chili peppers and the beet in a pickle jar. Peel the turnips and the beet, quarter and cut into slices, about half a centimeter / 0.2in thick. Chop the celery stalks into 5 cm / 2in pieces. Cut the chili peppers in half and remove the seeds. Add the vegetables to the jar. If the liquids do not cover the vegetables, add more water with one teaspoon of salt and one spoon of vinegar per glass. Close the jar tightly and leave in the shade for 4 days [Turn the jar upside-down every day or so – just to mix well – while it pickles] before moving to the fridge.

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