Frustrating experience using pressure cooker for the first time

I have at least a passing interest in storing food in Mason jars for winter use.  My first attempt at canning was frustrating, haven't tried since.

I had a large garlic harvest a few years ago.  Filled five jars with peeled cloves up to the lip, then poured olive oil in each jar til all was covered.  Filled to maybe 1/2 inch from the top of the jars.  Lids on.

All-American model 921.  Put the jars in the pot, did what the directions said as far as how much water to put in, and how to cook.

After the pot cooled, I opened it.  What a mess.  Most of the oil escaped the jars and was in the pot with the water.  The jars, though sealed, only had about 2 inches of oil in each, so most of the garlic had no oil touching them.

My intention was to have Mason jars full of garlic and garlicky olive oil, that I could use to cook with over the winter.  What did I do wrong, that led to most of the oil escaping the jars?

Hi Gary;
I'll start by telling you I know nothing about canning.
But how frustrating on your first attempt!
I like your idea of storing peeled garlic in olive oil.  
I wonder if you needed to attempt canning at all?  Could it be that submersion under oil with no air would be enough?

Like I said I really know nothing about canning or preserving...  Now if you want to talk rocket mass heaters I'm your guy!
Hopefully an experienced canner will chime in soon!

Just so you know, there is a chance of botulism, in non-pressure-canned garlic - particularly, in oil, as it is an anaerobic toxin. To be safest, I only dehydrate it, for long term storage.

My All-American Canning Book gives several reasons why the liquid is lost during processing. It is on page 40 of my book.

Jars may be packed too full, leaving air bubbles in the jar, food packed too tightly, and what I feel maybe the problem:

Lowering the pressure too soon or maybe the food was processed at too high a temperature.

How did you cool the canner?  Was there a steady pressure at all times?

I grow a lot of garlic as well. We use maybe 2-3 cloves per week in cooking and give a lot away.   The lady of the house will weave the tops together about a dozen or so per 'strand'and stores them in the pantry for about 6 months.( They are pretty so the is usually one hanging in the kitchen)  She runs the rest through her garlic press and packs into pint jars / processes them to use for the second 1/2 of the year. Funny thing, after canning it has a blue hue to it.  I know it is not recommended to can garlic but she adds acid to get the PH she wants and processes about 10 min. longer than she does onions. It does lose some of its bite so use extra when cooking to get the flavor your looking for.

In my understanding, the oil is incompatible with pressure canning.  The approved canning recipes for fatty meats even demand that fat be trimmed away and excluded to the maximum extent possible.  Fat does not behave the same way as water with regard to heat penetration nor expansion/contraction in the jars, and behaves unpredictably, as you learned.  Safe canning is all about predictability.

I don't know how to can garlic, but I'm pretty sure you can't safely or reliably pressure can it in oil. Sorry!

My guess would be the water in the garlic boiled and forced the oil out of the jars. If the jars were isolated from the botton of the pot, I agree with the possibility that the pressure dropped too quickly.

I have found pickling garlic to be the best way to can it. It doesn't have to cook for so long so the flavor is more intact. I do confit garlic (cook in olive oil) but that gets refrigerated. And I freeze whole cloves as well.

As others have mentioned, pressure canning in oil isn't recommended. Neither is storing garlic in oil at room temperature because of botulism.

Gary Numan wrote:
After the pot cooled, I opened it.  What a mess.  Most of the oil escaped the jars and was in the pot with the water.  The jars, though sealed, only had about 2 inches of oil in each, so most of the garlic had no oil touching them.

I have no experience with pressure canning, but here in India we use pressure cookers every day without problems. I learned early on, that if you cool the pressure cooker with cold water and open it as soon as you can, the objects inside may still be well above the boiling temperature at normal atmospheric pressure, so in this case they will boil or explode. It's important to cool the pressure cooker for long enough that objects inside (such as a jar full of liquid or other stuff) are also below the boiling temperature at your altitude.

I do boiling water bath canning for acidic things like fruit jam and tomato products. I preserve garlic by simmering in oil as confit, but certainly according to American canning rules it wouldn't be considered safe. Apparently it's an old traditional method in France and considered safe there. It is basically: cover the garlic with olive oil and a bit above the garlic in a pot. Simmer for one hour. Transfer to a clean jar and keep cool. I guess the hour-long simmering makes it safe by some standards, but I guess not by American official standards.

Thanks everyone.  I read your suggestions as to what may have happened, and this stuck out:

What made me think that canning IN OIL was a good idea??!  

N00b mistake.

I'm sorry that your pressure canning endeavours didn't work out well. I grow garlic and I find the best way to store it is to peel it, put it in the food processor and then into the dehydrator. I use a coffee grinder to grind the powder into garlic powder. It is delicious. The dehydrated garlic lasts  for a very long time. Others have already commented on the pressure canner not working with oil. If you want to try something this growing season, do some carrots. They work beautifully in the canner and pretty sure you will have great success and want to do more pressure canning.