Friday, March 14, 2008

Pressure's on



Dudes. I bought a used pressure canner!

In case you don't know, a pressure canner is different from a pressure cooker, which is a smaller pot used to quickly cook beans and stews. Pressure canners are usually much larger--my behemoth comfortably holds eight quart jars.

Betty MacDonald, author of the sometimes funny homesteading opus, The Egg and I, famously hated them. In one of the chapters from Egg, she writes: "Canning is a mental quirk just like any form of hoarding. First you plant too much of everything in the garden; then you waste hours and hours in the boiling sun cultivating then you buy a pressure cooker and can too much of everything so that it won't be wasted. Frankly I don't like home-canned anything, and I spent all of my spare time reading up on botulism..."To her I say, girl, you've never tried my dry-farmed canned tomatoes. But like Betty, I do worry about botulism, and that's where the pressure canner comes into play.



The beauty of a pressure canner lies within this formula: PV=nRT where R is a constant and n has something to do with quantities, pressure (P) is conversely related to temperature (T). When pressure goes up, temperature goes up too. Canning jars in a pressure canner increases the pressure and thus increases the boiling temperature. Harold McGee in his bible, On Food and Cooking, says it can reach 250 degrees F in a pressure canner. This higher temperature effectively kills all the spores which cause botulism in the jar.

It also means canning my tomatoes this summer will use much less energy, the water bath method that I've used in the past required one hour to process, using the pressure canner will cut that time in half. Wahoo!



By the way, I bought this gem from a gem of a guy named Dan at the Old Oakland farmer's market. He's usually there with a table of awesome cast iron cookware. Check him out. The Old Oakland Farmer's market is held on Friday mornings.

11 comments:

xtinehlee said...

dude--this looks awesome. i am having visions of your future blog tomato canning blog posts!

in other news...i planted tomato plants this year. after a long break from them! i figure gophers won't eat tomato plants. and i'll deal with the rodents.

samin said...

wowza--the pressure canner is a majorly pro gadget. i just upgraded from the crazy june taylor oven method to a steam canner, which i lurve. i need to come spy on your pressure canner, though--i'm really curious to see it in action.

Megan Lynch said...

Very cool! I looked for one used on Craig's List but ended up buying one new since I couldn't find one in the capacity I wanted. I just got "Putting Food By". Now all I need is some produce to practice on...

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Riana Lagarde said...

I am so green with envy, would you believe that I was reading about this very same stuff yesterday as I pilfered some more canning quart jars from mamie's stash.

for my birthday, now you know what i want!!

ps for the canners out there, the big B can't live in acid, i think its pH of 4 or below or above, shit, i would have to look that up. Thats why pickles are just fine and dandy.

Unknown said...

I've done the tomatoes and pressure canning and I didn't like the results. Now I may have done something wrong, but the tomatoes in my quart jars pushed out from under the lids and made a mess of everything.

The reason I tried it is that I read that pressure canning tomatoes instead of normal water bath creates a more nutritional product. Botulism isn't as much of a concern since tomatoes are so high in acid.

So, I have been sticking with the water bath for tomatoes, but will be very interested to hear about your results.

As an aside, I also like to sauce down some of the tomatoes first and back-fill my jars with the sauce after stuffing them with tomatoes. I end up with a product closer to what is available in the mega-mart and I have more versatility with them for things I cook.

Novella Carpenter said...

hey y'all;
christine: good--what kind didja plant?
samin: i'm finally better, will sked a tea session soon
megan: i'm dying for some apricots
riana: i'm on the lookout!
will: hmm, i'll experiment with the tomatoes and the pressure canner, but i got it more for things like canning beans and corn, peaches and plums without having to add vinegar or sugar to stave of botulism. my tomato canning involves smashing as many fresh toms into a sterilized jar, cooking them down in a water bath until they melt down a bit, then adding more toms, put on the lids and then process for about an hour, under an inch or so of water. the results are sublime, better than any canned tomato i've ever had, and almost better than fresh. because you don't lose the nectar, which forms a 3 inch layer in the jar after awhile. sometimes i just drink the jars....

Tanya Breese said...

Honestly, I'm intimidated by any kitchen gadgetry with the name "pressure" in front of it.
My grandma was the queen of canners. I should have learned a thing or two from her.
Enjoy your canning!

Unknown said...

please most definitely post your result of canning the fruit without the sugar. Thats something I have been tossing around in my head for awhile now. Looking forward to it,

~will

Unknown said...

Hi, new to your blog, Groovy Green blogged your SFG article, which linked your blog, and I'm subbing. I bought a used pressure canner off eBay, then a few months later we found one a few streets over in a 'cleaning out the house' pile waiting for monthly big trash.

I couldn't believe anyone would toss a pressure canner that had everything, but when we got home we found out why. I wasn't able to remove the lid, but my husband could. So we kept it, but I haven't tested it yet and forgot about it till now. Now I'll have to buy some meat or make soup over the weekend so I can test it while he's at home (to be the canner opener LOL).

Novella Carpenter said...

shreela: just be careful--they can explode. betty macdonald ended up destroying hers in a corn blow-out, and she ended up with niblets on the ceiling, walls, etc. so i'd test it with plain water first.
have fun!