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Thread: Question for home canners about sterilizing jars

  1. #1
    Join Date
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    Question for home canners about sterilizing jars

    I am planning an apple day on Saturday. My plan is to make applesauce and apple butter and can both in a boiling water canner (not a pressure canner). I'm going to have a lot of jars to sterilize.

    I have the day off of work on Friday and I was wondering if there was a way I can wash and sterilize my jars on Friday. I would put them back into the boiling water to heat up before I fill them and do the canning, but I was hoping to not have to have to time them.

    If I boiled them on Friday and set them somewhere and covered them with a towel to keep anything off of them, would they stay sterile until Saturday morning, or do I need to do them as I am ready for the jars (which is how I normally do it, I was just hoping to do some of this ahead).
    “When one door of happiness closes, another opens; but often we look so long at the closed
    door that we do not see the one which has been opened for us.”

    Helen Keller (1880–1968)

  2. #2
    Join Date
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    Hi Lara.

    Sanitation and sterilization is something I've had a great deal of experience with in my cheesemaking and brewing hobbies.

    If you don't have a pressure cooker then you have two options of sanitizing your equipment:
    1. Dry heat
    2. Boiling (as you know)

    If you want to use dry heat, you can use your oven to sterilize your clean jars. (maximum protection against microbes)

    * Clean your jars and let them dry.
    * Cover the jars loosely with the lid and cover the jars tightly with aluminum foil. Do _NOT_ close the jar, only keep the lid loose or your jars will burst in the oven.
    * Insert your clean jars onto a tray in the cold oven.
    * Heat the oven to 170°C (340°F) and let the jars sit in the oven for at least an hour and a half (the jars take a little longer to heat up).
    * Let the jars cool down in the oven
    * Seal the lid on the jar, make sure to keep the aluminum foil tightly wrapped on.
    * Use the jars at a later date, they should stay sterile until you choose to use them.


    Quote Originally Posted by Wikipedia
    The proper time and temperature for Dry-Heat sterilization is 160°C (320°F) for 2 hours or 170°C (340°F) for 1 hour.
    If you want to use wet heat (boiling) then you can use a clean sheet of aluminum foil to cover your jars (seal the opening on each one with one foil).
    This should likely keep your jars sanitized for some time.

    I'd not use a towel to keep things clean, I'd much rather use new aluminum foil or saran wrap to cover the jars since there is no dust in the foil or the wrap.

    (woohoo, my first post on this forum and I'm able to post something useful! )

  3. #3
    On my "apple days" I set up my oven the night before. Put the jars in on baking sheets. Have the oven set to turn itself on about 1.5 hours before I plan on starting (I add 30 minutes because the oven has to pre-heat).

    I do not wrap my jars in foil. I do keep a saucepan of simmering water to sterilize the inner lids. I don't put those in the oven.

  4. #4
    Join Date
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    Appleton, WI
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    I have taken a free canning course offered by the University of Georgia, and have also spent a lot of time on the Gardenweb forums chatting with master canners and other canning experts.

    The general consensus about sterlizing jars is that it is NOT necessary if you are doing a hot pack- putting a boiling hot item into your jars- that in itself is more than enough to sterilize and kill off any baddies that may be lurking about. Filling your jars with hot applesauce and apple butter should be enough to sterilize. If you were doing a cold pack- then you would need to go through the steps to sterlize the jars. This also has to do with the processing time. If you put your filled jars in a boiling water bath for MORE than ten minutes, that's plenty of time, and you don't need to worry about sterlizing.

    Obviously, the jars still need to be nicely cleaned- I wouldn't hesitate to use a canning jar that I'd washed on Friday to put applesauce in on Saturday. But I would probably give it a rinse in nice hot water. I like to use my dishwasher for washing canning jars, because I can get them all done at once, and I have a sanitize cycle that I use just for my own peace of mind.
    Merry: I don't think he knows about second breakfast, Pip.
    Pippin: What about elevenses? Luncheon? Afternoon tea? Dinner? Supper? He knows about them, doesn't he?


    I'm food bloggin' almost daily at Tummy Treasure!

  5. #5
    Join Date
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    Quote Originally Posted by LadyWild View Post
    On my "apple days" I set up my oven the night before. Put the jars in on baking sheets. Have the oven set to turn itself on about 1.5 hours before I plan on starting (I add 30 minutes because the oven has to pre-heat).

    I do not wrap my jars in foil. I do keep a saucepan of simmering water to sterilize the inner lids. I don't put those in the oven.
    I realize people have been using their ovens to do this for years, but every time I hear about it, it makes me very nervous. Canning jars are not made to withstand that kind of heat for that length of time. I think there's a real risk to breakage, and you reduce the shelf life of the canning jars by baking them.
    Merry: I don't think he knows about second breakfast, Pip.
    Pippin: What about elevenses? Luncheon? Afternoon tea? Dinner? Supper? He knows about them, doesn't he?


    I'm food bloggin' almost daily at Tummy Treasure!

  6. #6
    Join Date
    Sep 2002
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    Appleton, WI
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    4,635
    Here is an excerpt from the National Center for Home Food Preservation.

    "Empty jars used for vegetables, meats, and fruits to be processed in a pressure canner need not be presterilized. It is also unnecessary to presterilize jars for fruits, tomatoes, and pickled or fermented foods that will be processed 10 minutes or longer in a boiling-water canner."

    So just make sure your jars are nice and clean, and you're good to go.
    Merry: I don't think he knows about second breakfast, Pip.
    Pippin: What about elevenses? Luncheon? Afternoon tea? Dinner? Supper? He knows about them, doesn't he?


    I'm food bloggin' almost daily at Tummy Treasure!

  7. #7
    Join Date
    Jun 2000
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    The applesauce and butter mad be processed for 10 minutes or more, but many of my jams are only processed for 5 minutes in small jars. I put my jars into the canning pot when I fill it with water and bring it up to temperature and let it come up to a boil while I get my other things started. I let the pot simmer, so the jars stay right at the boiling point while I cook my jam or whatever and they are hot and ready for filling. I have also used my dishwasher and my DW will keep them pretty warm for a while if kept closed.

  8. #8
    Join Date
    Jun 2000
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    Alaska
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    For the recipes which require less than 10 minutes in a water bath I sterilize the jars and put them upside down on a clean towel if I have more than I can can in the next batch. If I am doing a single batch (whatever will fit in the waterbath canner) I put them in the canning pot like Beth does and pull them out when I am ready to fill.
    Anne

  9. #9
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    Quote Originally Posted by Beth View Post
    I put my jars into the canning pot when I fill it with water and bring it up to temperature and let it come up to a boil while I get my other things started. I let the pot simmer, so the jars stay right at the boiling point while I cook my jam or whatever and they are hot and ready for filling.
    This is normally what I do too, but I'm going to have a large pot of applesauce and apple butter going at the same time, and my canner won't accommodate as many jars as I will have. I will probably do this to get them up to temp when I'm ready to fill them but I will have 30+ jars that I'm going to be working on.

    This does make things a lot easier. I will get the jars ready on Friday and then heat them on Saturday as I'm ready for them. Thanks, all!
    Last edited by LaraW; 10-09-2012 at 08:09 PM.
    “When one door of happiness closes, another opens; but often we look so long at the closed
    door that we do not see the one which has been opened for us.”

    Helen Keller (1880–1968)

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