canning 101

May 10, 2009

here’s the post i am going to refer you back to again and again. these are the basic steps in hot water bath canning which means boiling the filled jars until they are hermetically sealed. this vacuum packed seal, along with the acidic contents keeps the food safe from bacteria and in particular clostridium botulinum.

whenever we ‘can’ or preserve jams and pickles in this way they can be stored in a cool, dark place for a year or more, and do not have to be put in the fridge until they are opened. the hot water bath canning method only works safely with high-acid foods, i.e. fruit preserves & pickles, and will apply to everything that we can here and at tigress in a pickle. so please for safety reasons, follow the recipes and these directions completely and accurately, or, you can put your preserves directly in the fridge and skip this part.

but, this is the fun part. in fact
you’ll most likely have a ball!

steps in hot water bath canning

1. clean jars with hot soapy water or in dishwasher.

2. pre-heat jars by placing open, empty jars on rack in canning pot and lower down. or, if you do not have a rack, you can place some screw tops down first, the object being to keep the jars from touching the bottom of the pan. fill canning pot with hot water until the jars are full. place lid on canning pot and heat on cooktop until hot but not boiling.

note on sterilizing jars:
if the recipe states to boil the filled jars for 10 minutes or longer then the jars do not have to be sterilized at this step. if the recipe states to boil the filled jars less then 10 minutes then you will want to sterilize them here – just boil the empty jars for 10 minutes at a full rolling boil.

3. prepare recipe while jars are heating, keeping jars hot until ready to be filled.

4. heat jar tops 5 minutes before jars are to be filled. place flat lids of mason jars, or the rubber gaskets for weck jars in a bowl with hot water (this water should not be boiling). do not place metal screw caps in heated water, but you should place the weck glass tops in the heated water also if using.

5. remove each jar as needed when food is ready to be processed. my rack hangs on the side of pot so i lift the entire thing up for easy access to the jars. this is where either a jar lifter or a silicone glove comes in handy. place a folded kitchen towel on counter and place hot jar on towel. (a hot jar placed directly on a cold counter top could break). no need to dry jar before filling. i turn it upside down and give it a couple of pats on the towel to shake out any excess water.

6. fill jars one by one. food can either be ladled or sometimes poured into jar. here is where i use my trusty funnel. headspace is very important: too much space between food and top of jar and it may not seal correctly, too little and the food my be forced out of jar during boiling. as a general rule 1/2 inch headspace is perfect. unless otherwise stated in the recipe food should always be processed immediately following the cooking stage, i.e. still hot.

7. remove air pockets by running a small rubber spatula or chopstick around the side of the jar. for most jams you will not have to do this, but if there are large pieces of fruit, or with most pickles you will notice air pockets and will want to get rid of them to ensure a proper seal.

8. place lids on jars after wiping rim with a damp paper towel to remove any misplaced food. place the flat lid on if using mason jars, or the rubber gasket and glass lid if using weck jars. for the masons put the screwcaps on and tighten with fingertips. this means that you want the screw cap secure but not overly tight. for the wecks once you have the rubber gasket encircled around the inside of the glass top and placed on top of jar, put two metal clips on, directly across from each other.

9. adjust water to cover by 1 inch once jars are full and lowered back down into pot. if you have different size jars in the canner, cover the tallest one by 1 inch. note that jar size should not vary too much within a recipe.

10. process jars according to individual recipe as processing times vary and are based on size of jars, density and composition of food. processing is the amount of time the jars must be immersed in a full rolling boil. do not start timing until the boiling becomes steady & vigorous. the water must remain at a full rolling boil throughout. a kitchen timer is helpful here for accuracy. for safety reasons and to ensure that the food does not overcook, do not alter the processing time.

note on high altitude canning: the higher your elevation, the lower the temperature at which water boils. if you are over 1000ft adjust as follows:

1001-3000 ft: increase processing time by 5 minutes
3001-6000 ft: increase processing time by 10 minutes
6001-8000 ft: increase processing time by 15 minutes
8001-10,000 ft: increase processing time by 20 minutes

11. leave jars in pot for 5 minutes at end of processing time. once heat is off and lid is lifted, a few minutes here will allow for adjustment to temperature change. i lift the rack up and hang it over the sides so that the jars are not in water, but they can be left down below also.

12. lift jars out of canning pot with either a jar lifter, or using a silicone glove and place on kitchen towels. try not to tilt jars excessively. do not adjust the screw caps or metal clips, do not worry about any water gathered on top of jars. let jars rest for 12 to 24 hours to cool completely. you may hear popping noises from the masons, this is the sound of the jar sealing.

13. check the seals after the 12 to 24 hour cooling period. for the masons push down in the center of lid, you should not hear a metal popping noise, and it should concave slightly. for the wecks the tab on the rubber gasket should be pointing down. take off the screw caps or the metal clips and here is the real test: use your fingertips to pick up the jars by the lid only. if it is properly sealed you will be able to do this, if it isn’t the lid will come off and the contents of the jar will spill everywhere. so do it slowly and with your other hand under the jar.

note on unsealed jars: if any jars failed to seal, you can wipe the rim and try again using a new flat top or rubber gasket. if it is only one or two jars the easiest solution might be to put them directly in the fridge and enjoy immediately, as in some cases reprocessing overcooks the food and affects quality.

14. store the jars in a cool, dark place without the screw caps or metal clips. this means out of direct light and in a temperature range of 55 to 78 for best keeping quality. labeling the jars with date and contents is important because no matter how much you think you will remember what is what, you won’t. trust me.

15. examine each jar before opening by checking for bulging or leakage, and rechecking the seal as described above. if seal has come undone or you notice anything funny, do not eat contents, discard food and sterilize jar. screw caps or metal clips should be refastened after opening for fridge storage.

don’t let this last bit scare ya, or that link above. because if you follow these steps and the recipes completely and accurately you will have many jars of good and safe eats!

for a list of tigress’ picks for canning equipment go here, or check out my larder on amazon.

time to get cannin’ peeps!

but safety first…so read up, cause i’m not doing this for my health ya know

…oh wait, i am

and yours too!

update 4/22/2011:

the high altitude information above is taken from the usda guidelines. please note that some reliable sources do not adhere to the above, rather they recommend adding 1 minute per every 1000 feet above sea level. example – a 10 minute processing time at sea level to 1000 feet would be 11 minutes at 1001-2000 feet above sea level, 12 minutes at 2001-3000 feet above sea level, etc.

Comments Closed

  • pixen says:

    Hi Tigress… thank you for sharing your experiences and important informations with jammin' & picklin'.

    This prompt me to try my hands doing some because I was left with some gadgets by my lovely mother-in-law 10 years ago. She did lovely cherries preserved in alcohol and confitures from fruits like cherry and raspberry (from their 60 yr old tree in the garden). She used beewax to form a lid for the bottles instead and wrap a plastic with rubber bands around the rims. I was quite surprised that the confitures didn't spoilt on top of their fridge for years ( I saw the dust collected on top of the plastic LOL).

    I'm looking forward to your delicious entries. Warmest regards!

  • tigress says:

    hi pixen,
    welcome! I am so glad that i am peaking your interest. stay tuned because fruit season is just beginning in my part of the world!

  • The Fudge Fairy says:

    I have already bottle my Rhubarb Champagne and am now about to make the Gingery Rhubarb Chutney!Fruit season is in full force down under :-)

  • paul a'barge says:

    This is wicked weird: there are no Weck Canning Jars for sale on Ebay! I think that's a first.

  • paul a'barge says:

    My ex-canning friends tell me that I can use one of the blue speckled porcelain Turkey roasting pans as a canning pan. However, for my 1 Qt. Mason jars, I do not think the sides are deep enough to submerge the jars.

    Can I turn them over and boil them while on their side? Probably not, huh?

  • tigress says:

    paul – welcome! absolutely no, jars need to be right side up when hot water bathed. and the water must be covering the tops of the jars by a good 1 inch. however your turkey roasting pan could be used for smaller jars that meet this criteria.
    …oh, and i am not surprised about the lack of wecks on ebay. everybody wants them! ;)

  • Shannon Ryan says:

    My jam is coming out kind of separated.. can i give it a little shake to mix while it's still hot? (I already did this so hopefully it doesn't mess things up! :)

  • tigress says:

    shannon – you can let it sit for 5 minutes in the pan and give the whole batch a stir before filling jars.

  • Anonymous says:

    I am trying to preserve some herbs (basil, thyme, oregano, etc) in jars but am not quite sure how to seal the jars or what to add as a preservative. Any help out there? Joyce

  • tigress says:

    joyce – sorry, i don't know how this one slipped by me for so long. the sealing info for jars is above. you would need to use vinegar to submerge the herbs. but for herbs i would chop them, put them in ice cube trays with some water and then freeze. once frozen, take them out of the trays and bag 'em. or dry the herbs – oregano and thyme are particularly good dried. i wouldn't advise canning them unless they are part of a vegetable or pickle preserve.

  • Jene says:

    Thanks a lot for sharing this. I've decide to take up jamming and jellying and pickeling as a hobby. All involve canning, if you've noticed. Cheers!

  • Curious New Canner says:

    Do you prep the jars (sterilize before filling) and process the jars in the same pot (taking a sterilized jar out filling it, putting it back in filled and then taking the next empty jar out and repeating)?

  • tigress says:

    curious new canner – welcome! yes when i sterilize my jars i do it exactly as you've said. remember that if your recipe calls for processing your filled jars for 10 minutes or more (if you are at an altitude of 1000 feet or less)then you do not have to sterilize beforehand.

    jene – welcome & happy canning!

  • Robin Feltner says:

    I cannot wait to try canning. I've been wanting to for a long time, and I've decided I'm not going to let another summer get away from me without doing it. Great post!

  • julie says:

    I just finished canning and couldn't seem to resist screwing the rings down after I pulled the jars out of the hot water. How bad is this error???

  • tigress says:

    robin feltner – do it! and have fun! :)

    julie – how bad it is depends on if you've upset the seal or not. you'll want to let them sit for at least 12 hours until they have completely cooled. to make sure that they have 100% sealed unscrew the band and take it off, then pick up the jar by the lid. if you can pick it up by the lid, then they've sealed. leave the screw caps off to store.

  • Bobi says:

    Once I've tested the seal by taking screw caps off, can I put them back on? I would be giving some jam to friends so I think they would need that. Thanks. Your site is great!

  • tigress says:

    bobi – yes, after they are completely cool you can put the screw caps back on. but do not screw them too tightly or you could affect the seal, they can be screwed tightly once opened.

  • sean nelson says:

    i have an industrial steamer. is it safe to sterlize and can with this instead of boiling water?

    • tigress says:

      the USDA recommends only the hot water bath method, or pressure canning. you don’t need any special equipment for the hot water bath method – just a big pot!

  • sean nelson says:

    how long do most jams and jellies last in the fridge without opening that have not been canned?

    • tigress says:

      the rule is usually about one month. but i have had them last much longer than that. it depends on the sugar content. typically the more sugar in the preserve, the longer it will last in the fridge.

  • lauren says:

    ok, i love this tutorial and used it for a guide for my first canning experience. thank you!
    one question – i made pickled onions and followed the recipe well and your instructions. the seal worked – yay! my concern is that even though i ran a chopstick around the jar to eliminate air bubbles (and thought i did a good job) there are definitely air bubbles in the jars. is this ok? or do i get rid of the onions? i really want to eat them but i’m terrified at the same time! :)
    thanks so much!!!

    • tigress says:

      as long as they have sealed you do not have to worry. even experience canners (moi) end up with air bubbles sometimes. the most important thing for safety is the right amount of acidity (if you followed a reliable recipe then you are good) and that the jars have sealed. a few air bubbles here and there are fine. happy canning!

  • Monica says:

    I just got done canning my own salsa and committed the grand error of laying some of the jars on their side while boiling. They appear to be sealed, tomorrow am will be the real test but would you say they are not really sealed regardless because of the way I did this? Also I don’t have a wire rack to put on the bottom of my stock pot that I boiled these in so I just set them in the pot, bottoms touching the bottom of pot. Is this also bad? I love the idea of preserving my food but am scared to death of botulism and worried my canning process is all wrong. What do you say?

    • tigress says:

      you definitely don’t want to lie the cans on their side while hot water bath canning because chances are they will not seal. but if they have sealed then they are fine. next time you can, if you don’t have a wire rack, place some of the metal screw tops on the bottom of the pot and create your own!

      neither of these two things contribute to botulism, that has to do with the amount of acid in the jar, but you might want to dig into these jars sooner rather than later because the seals may not be as strong as if they were canned upright.

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