Canning sterilizing question

[yardfarmer]

My DW and I have been canning for years, and we just got the latest edition of the Ball Canning book. The book says the only way to sterilize jars is to boil them.

Last year we were doing several batches of tomatoes, pears, pickles, etc. and we used to oven to heat the jars over 212 degrees (225) for 10 -15 minutes, then reduce the heat to around 190. This seemed to work, but just curious why the Canning book says boiling it the only way to go.

Anyone know why boiling is the only method of sterilizing? Any comment on the oven method will be appreciated.

 

[Whitewater]

I can't answer that one, but I know that our dishwasher does an excellent job of sterilizing the beer bottles we use in home brewing (and all of the rest of the equipment as well!), so I just assumed that I'd sterilize my canning jars and lids in our dishwasher.

Granted, we have a relatively new dishwasher that's much more powerful than the dishwashers of yore (it's absolutely like the commercials you see on television, we can put an un-scrubbed, un-pre-soaked casserole dish in the dishwasher, run the whole cycle, and voila, a totally clean sparkly dish!!! It's like magic!) so if you have an old dishwasher that doesn't steam clean, probably boiling is the best option.

I have never thought about baking glassware to sterilize it, but I suppose it's possible. I know that baking your cast iron helps clean those stubborn foods off of it . . . maybe the same principle applies?


Whitewater

 

[journey11]

I use the dishwasher too, but I guess that's pretty nearly the same as boiling since the water reaches that temp. I like to dump in a cup or so of white vinegar in the rinse cycle so they come out sparkling clean. The only thing I could think with the oven would be the possibility of food residue touching the jar or maybe smoke from spilled grease. I would think that even those would be sterilized at that temp though.

 

[Chickie'sMomaInNH]

i've been doing the dishwasher too since i have a Bosch that heats the water really hot! and my house water gets to 149deg (house inspector and plumber friend confirmed that!) so the dishwasher doesn't have much further to heat the water up to boiling point!

 

[oberhaslikid]

I bought a Portable dish washer just to do my canning jars. I married my other dishwasher.

 

[HunkieDorie23]

My DW and I have been canning for years, and we just got the latest edition of the Ball Canning book. The book says the only way to sterilize jars is to boil them.

Last year we were doing several batches of tomatoes, pears, pickles, etc. and we used to oven to heat the jars over 212 degrees (225) for 10 -15 minutes, then reduce the heat to around 190. This seemed to work, but just curious why the Canning book says boiling it the only way to go.

Anyone know why boiling is the only method of sterilizing? Any comment on the oven method will be appreciated.

I have never thought of the oven to sterilize jars but after I do sterilize they I do put them into a hot oven about 200 degrees to keep them hot until I use them. It probably does work.

 

[patandchickens]

The ('cover-their-butts') reason why it is officially not recommended to use an oven or dishwasher for jar sterilization (see below about "sterilization" though) is that there is no particularly good guarantee that the jars are coming up to temperature well enough long enough to kill germs. Ovens often have inaccurate thermometers and individual spots that are hotter/cooler than the thermometer indicates; dishwashers don't even usually HAVE accurate thermometers, and again, hot/cool spots; and because neither air nor sprayed water transmits heat all that well (compared to a water *bath*), there are also potential issues involving the jar not being exposed to that temp for long enough for all the glass to be hot enough.

That said, I would make three observations:

1) it is rarely really necessary to sterilize jars, in fact I don't do it at all because everything I can is either processed for long enough that true sterilization is not really needed, and/or is sufficiently sweet or acid that nothing too horrible will grow in there anyhow. (I am willing to risk losing a jar here or there to spoilage. But I can't actually remember the last time I had one go funny on me). For most canning (at least of the sort that I do), all you really need to do is get the jars HOT so they don't crack when filled, for which an oven or dishwasher are perfectly fine;

2) if a person is doing canning without processing the jars (unprocessed pickling, or using wax or inversion for jams/jellies), then clearly you have enough tolerance for the possibility of a few germs from time to time that I do not see that you're likely to worry about what some gummint agency says about sterilization ;

3) if you DO need to sterilize jars for what you're doing, you can very easily sterilize one batch's worth in the boiling water canner itself, as you bring it up to temperature. So the only situation where you'd need a different method of sterilization is if you are going to do multiple batches in series.

4) botulism is not a problem with sufficiently-acid foods, and sufficiently-sweet foods (e.g. jellies/jams) have some further degree of protection against normal spoilage too. Thus, with anything where sterilization *might* be an issue, all you are really risking is losing some jars to detectable-if-you're-paying-attention type plain ol' spoilage, not contracting unexpected botulism.

JMHO, good luck, have fun,

Pat

 

[Lavender2]

It has more to do with the jar... they are not designed to be exposed to prolonged dry heat... the jars can crack or explode.
Heat circulation in ovens is not always good, as well as even temps. This is why oven canning is no longer recommended also.

Many people use the oven for keeping the jars hot though... and recommend it.
I have always used a kettle to heat the jars, because that's how grandma did it

 

[ducks4you]

Most of MY canning is hot food into hot jars. I go hot to hot, and I don't break my jars. (Don't know WHY they call it "canning" when we are really using glass jars! )
When I recycle (re-use) a jar, I hand wash it, run it through the dishwasher, take out and put a brand new seal on it and store clean and dry.
When I fill my jars, I have a big pot of water at a low boil going. I use pinchers and put my jar in there to sterilize. I also sterilize the lid and seal, but I only dip those in for about 30 seconds. When I take the jar out of the boiling water, I pour the water out, and IMMEDIATELY fill with boiling "canning stuff--you know, the tomatoes, jelly, etc.", wipe the tops, as you do, seal and screw on the lid, then IMMEDIATELY into the bath.
For the odd times when I start cold, I STILL use a hot water bath. THEN I have clean towels on a clean kitchen table. When I remove the jars and lids I place them upside down to dry. I put cold food into cold jars (clean tops) and put them into a COLD water bath, then slowly heat that to a boil. When that boils, I start the timer.
Hope this helps--from a canner who was learned many things the HARD WAY!!

 

[Ridgerunner]

so I just assumed that I'd sterilize my canning jars and lids in our dishwasher.

Whitewater

Do you have a problem in the dishwasher with the lids getting banged around and bent or dented, possibly not sealing properly?

I wash my lids in hot soapy water, then rinse them well. I bring a sauce pan of water to a boil, take it off the heat, and drop the lids in until I am ready to use them. The rubber is soft and undamaged and the lids as as clean and sterile as I can reasonably get them.