Kim, my friend from UCLA, posted on her blog about making persimmon jam. As improbable as this may be, I don't think I have ever, in my life, tasted a persimmon. Still, the recipe sounded delicious, mostly because all jam sounds delicious to me. Especially during these cold months (although, as I have discovered, Eugene isn't all that cold in the winter, it isn't even below freezing! I thought I was in for some winter) the thought of homemade canned goods warms my heart.
I have made several forays into the canning world, including making raspberry chipotle jam as a wedding favor back in 2008, and since we weren't totally sure of the guest count until the last minute that meant making about 170 tiny jars of jam. It was a crazy amount of work, but the result was (in my humble opinion) delicious. So tonight I have been thinking about jam and canning, where it came from and why it is so good.
Canning, like most methods of preserving, comes from the problem of keeping food before refrigeration was widely available. It was also a very important method of having enough to eat during the winter before we could have fresh fruits and vegetable shipped in from the opposite hemisphere. Basically, it uses heat to sterilize and a combination of acid and sugar to stabilize fruit (including tomatoes). After cooking the fruit and getting it into the jars (which makes a gigantic mess unless you have a jar funnel) the closed jars are submerged in boiling water, which increases the pressure and forces most of the air out. This leaves a little vacuum which seals the lid to the jar and insures nothing will get in or out for a long time.
Done properly, canned jam or tomato sauce will keep for a year, after which the risk of botulism begins to increase. Don't be too scared, botulism is extremely rare if you follow the rules for home canning. But be scared enough to follow those rules, and don't try to keep stuff for more than a year, botulism can kill you if not treated immediately. Check out this section of about.com for a great overview of those rules.
At this point, you should be wondering "what is this post doing on a 'green' blog? (or 'why would I risk botulism for this?)" Well, the answer is long, but bare with me, I think it is also interesting.
We all know that buying local is good for many reasons: it supports the economy and community that you live in, it reduces embodied energy from transportation, and it allows for a personal connection with your vendors (trust and accountability). But if you are really committed to buying local, and you live very far north or south of the equator, then that means no fresh fruit or vegetables for several months out of the year! Canning and other methods of preserving are your only way of getting around this problem. Much like our recent ancestors, but for very different reasons, it is an excellent idea for us to can the excesses of summer for the dearth of winter.
If you read my last blog post about efficient cooking (almost a month ago I know, sorry about that) you might be saying 'wait a minute, wouldn't canning in the summer be generating a lot of waste heat and burning a lot of energy?' Well yes, it would. And quite frankly, it puts me in an awkward position, you bringing that up. Nevertheless, when you compare the amount of energy required to properly can food compared to the energy that is used on a regular basis to ship food from the Cono Sur to America, and when you throw in the added benefits of supporting local economies, it is clear that canning produce from the local Farmers Market beats out mid winter berries and asparagus in the carbon footprint arena. Also, when you buy fruit in its prime season locally, it tends to be really cheap, because the local market is glutted with it just then. For the same reason, the fruits and veggies in the market that are on sale are usually the ones in season locally.
So in short: canning is great economically, ecologically, tastelogically (yes, I know that is not a word), and perhaps most importantly, it is one of those things that just makes us happy. After Courtney's and my wedding, due to the fact that a distant relative was also getting married at the same time (which meant much of my extended family had the dilemma of choosing which wedding they could attend) there were many, many left over jars of raspberry chipotle jam. We used it on toast and tortillas, in sauces, as salsa, with chicken, with fish, any way we could think of. We never once got tired of it. Home made jam, and canned food in general, is a labor of love, and as such it usually pleases the palate and warms the soul, and the green aspect may as well be an after thought.