Reducing the Canning Footprint

I had a minor freak out yesterday when, for a lark, I did a rough estimate of the energy costs of pressure canning.  On a recheck of my calculations I found a major error that put me off by a factor of 1000.  Oops!  After the error was caught I was relieved to find that - provided I started with water brought up to room temperature, and used a bare minimum of water, and ran a full batch through my pressure canner - I could can salsa for about one-sixth of a fossil fuel calorie for every calorie of preserved food.  If you want details about these calculations, find them in the comments.

The larger point is that this got me thinking about the carbon footprint of the food that I preserve.  Obviously, it's more energy intensive than the stuff we eat fresh out of the garden.  Going into freak out mode over what I erroneously believed was an absolute travesty of fossil fuel consumption made me scrutinize the food preservation process as a whole.  How could I whittle down the energy inputs to the food we preserve?  Here's what I came up with:

1. Can local products and minimize use of ingredients shipped from afar.  It makes sense to start with foods that don't have inherently high carbon footprints before they arrive in our kitchens.  Home canned food can only be as energy efficient as the ingredients that go into it.  Obviously, finding a substitute for sugar grown a long way off won't be easy for most people.  But we can opt to make lower-sugar jellies and jams.  It'll be healthier for all of us while also lowering our food miles.  Better still to can what we grow from seeds we start ourselves whenever possible.  Growing your own from seed you save yourself makes you a low carbon footprint rock star.

2.  Switch to re-usable canning lids.  Tattler lids are re-usable indefinitely, and are made from plastic which does not leach BPA - an endocrine disruptor that mimics estrogen.  BPA does no one any favors and is especially bad news for prepubescent children. Re-usable lids will entail a higher upfront cost that may not be feasible for everyone, though I believe it makes good sense both economically and in terms of energy consumption over the long term.  Fossil fuels certainly go into the production of the Tattler re-usable lids and rings, but far more energy goes into the mining of metal for the single-use disposable lids, as well as the BPA-containing plastic lining on those lids.  This is an investment worth working towards incrementally as your budget permits.

3. Prepare large batches so that you max out the capacity of your canner each time you fire it up.  The more food you get out of one run through the canning process, the lower the energy usage per jar.  Check the yields on canning recipes and try to scale up so that you fill your canner each time.  Write margin notes on the recipes you use regarding the accuracy of the stated yields so that you can work more efficiently in the future.  Also, make every effort to ensure that each jar seals successfully.  Each jar that fails to seal and requires reprocessing doubles the energy consumption to preserve that food.

4. Bring the water needed to ambient temperature (or better) before you begin the canning process.  In summer the water that comes out of our tap is roughly 59F/15C.  The canning process takes that water to 212F/100C and beyond.  That's exactly where the bulk of the fossil fuel is consumed - in heating water.  A few hours' worth of foresight can shave off a significant chunk of those fossil fuel calories.  All you need to do is fill the pots you'll need to use in the canning process well ahead of time.  A water bath canner full of 59F water will warm up nicely when placed in the full August sun for several hours.  Even if the pot only sits indoors on a cold stove for a few hours, our kitchen is very rarely less than 73F/23C during the summer months, and often much higher.  If you're more ambitious and better equipped, you could use a camp shower bag to get the water really hot (easily 100F/33C).  It may not seem like these small temperature differentials should make much difference, but heating the water is the major energy cost in the canning process.  Temperature is a measure of energy, and saving energy is the name of the game here.  I know planning ahead isn't the easiest thing in the thick of the summer gardening season, but in this case it's a free and relatively easy way to reduce your energy consumption.

5. As an obvious corollary to the above, use as little hot water as possible when you preserve food.  Leave only the required amount of water in the canner when you're ready to process the filled jars.  Extra water doesn't contribute anything to the process; it only consumes more energy for no purpose.  If you're pressure canning, you can sterilize your jars in the canner with only a few inches of water and preheat the canner in the process.  Just run the pressure canner with the lid on to the point that steam is being produced; you don't need to pressurize it.  Leave the canner closed until you're ready to fill the jars.

6.  If you happen to be blessed with a woodstove to heat your home, and are able to delay some of your canning to the cool months of the year, go for it.  In doing so, you would avoid using any fossil fuel calories at all, and you'd be piggy-backing food preservation on the necessary heating of your home.

Got any other energy-saving tips to do with canning or food preservation?  Please share in the comments!

Tomato Canning Begins

A friend is coming over in a few hours to can roasted tomato sauce with me.  I don't bother with canning whole or chopped tomatoes.  The roasted sauce serves equally well for pizza or pasta; we don't seem to miss store-bought canned tomatoes, so I don't see the need.  If you'd like to see how the roasted tomato sauce is made, check out my post on it from last year.  For the record, I pressure can this sauce at ten pounds of pressure for 25 minutes in quart jars.  But please consult a reliable canning guide rather than taking any anecdotal canning recommendations you find in the blogosphere.

My canning goal for this year with regards to tomatoes is to get enough sauce into jars to see us through two years.  I'm still traumatized by last year's late blight which left us with hardly any tomato crop to speak of.  I canned only three quarts of sauce, which we soon ran through.  I resolved to make a big effort this year if we had a good crop.  If blight rears its ugly head again next year, I'll be able to coast through with what I put up now.  If next year is a good tomato year, I can put up just one year's supply and still have a year's supply in reserve.  So far it looks like June and July's blistering heat and little rain have protected us from blight and set us up for a good tomato harvest.  My estimate for a two-year supply of tomato sauce is somewhere between 30 and 40 quarts.  I'm going to try my best to put that much up in the next three to four weeks as the tomatoes come in.  Extra quarts are always good to have for gifting.  If our own supply of tomatoes is insufficient, I may resort to buying locally grown.  But first I'm going to see how we fare on our own production.

Much of our cherry tomato crop is going to be smoked in our homemade trash can smoker.  We're still slowly working our way through the apple wood chips we made ourselves from the first pruning of our apple tree after we move in three years ago.  These are excellent material for smoking, and homegrown too.  After smoking, I dehydrate the cherry tomatoes until they are shelf-stable.  We then keep them on hand for adding to winter stews, pasta dishes, and polenta.  Super-sweet cherry tomatoes smoked over our own apple wood give a marvelous flavor boost to winter meals. 

Speaking of growing tomatoes, I have to gush a bit about the Speckled Roman tomato.  My last few posts have included pictures of this beauty if you want to see what it looks like.  I'm more and more impressed with it as time goes on.  This variety is a stabilized hybrid of Banana Legs and Antique Roman tomatoes.  "Stabilized hybrid" means that someone worked on the cross of the two parent varieties until they had a genetic line that breeds true.  In other words, it's now open pollinated.  In other other words, it's possible to save seeds from Speckled Roman tomatoes and reliably get Speckled Roman tomatoes from those seeds.  I like the fact that it's open pollinated.  I love their unusual and beautiful appearance.  I like both the texture and flavor - meaty and solid enough to make a good slicing tomato, but full of well balanced tang and sweetness.  I love the fact that they very rarely split; this characteristic redeems the only moderate production from each plant, since I can count on harvesting just about every fruit that forms.  And I really appreciate the Speckled Roman's ability to resist late blight, which I saw first hand last year.  This is only my second year growing this variety, but I'm definitely sold on it over other paste tomato varieties.  In fact, I'm strongly considering making it my primary tomato in future years and planting only a couple of beefsteaks and cherries. 

Hard Work

We had an overcast and coolish day on Friday.  It only got up to 77 F (25 C).  So I worked my butt off outside, moving mulch, planting the last few transplants that needed homes, watering, weeding, weeding, weeding, hilling potatoes, and generally doing much of the stuff that hadn't gotten done because the unseasonably hot temperatures had been driving me inside for too many hours each day.  We're now out of cardboard and newspaper.  It all got used up in lasagna mulching, and there are still pathways in the garden that haven't gotten the treatment.  I had to finally do a spit and shine on my filthy car, since I'd agreed to drive to the strawberry picking farm.  Then I spent a good chunk of time in the evening cleaning up some filthy canning jars I'd picked up for very little money through craigslist and trying to triage the kitchen mess.  It was a long day, was Friday.  After a shower I was more than ready for sleep but had to wait on the girls to retire for the evening before I could fall into bed.

Yesterday I was up early, getting my large containers ready for strawberry picking.  Serious gardening friend and I carpooled over to the U-pick farm, where I zipped through a little over 16 pound's worth of picked strawberries.  My lower back informed me that the strawberry picking felt an awful (and I mean awful) lot like gardening.  After that we nipped over to a tiny farmer's market organized by farming friend, where we found we were too late for asparagus or rhubarb. We consoled ourselves by grabbing evil baked goods for lunch (pecan-brioche sticky bun for me), and I picked up some raw milk cheese, spinach and scallions that were half way to being proper onions.

Back home by 1:30, I spent the next four-and-a-half hours processing my strawberries into 15 pints of jam and three half-sheet pans of frozen berries.  Amazingly, all the jam set up beautifully.  The secret, I found, is to simply follow the directions exactly.  (Well, except for skimming off the foam; I can't be expected to follow directions that lead to either waste or sugar overdose.)  This whole do-it-the-way-they-tell-you thing is surely obvious to other, saner people.  I'm just not much of a direction-taker in the kitchen.  I'm slow that way.  Anyway, we ended up with five well-set pints each of three different types of jam: straight up strawberry, strawberry-balsamic, and strawberry-ginger.  One special jar of the strawberry-balsamic also got several twists of very finely ground black pepper.  The quality control testing indicated that they were all delicious, though there wasn't any extra of that last black pepper variation.  That'll have to wait until we open that jar.  Of those we sampled, I think the strawberry-ginger may narrowly edge out the other two for our top pick.  We'll see.  This supply of jam had better suffice for the next year, considering how much sugar disappeared into those pint jars.  We should have some to give away as gifts too.  Now I kinda wish I'd put some into half-pint jars so that I could be generous, but you know, not too generous.

Around 5:30, my husband decided he wanted to make ice cream after all, so he snagged some of my frozen berries.  When that was done we improvised a very late dinner of hot dogs grilled with the oversized scallions, and washed them down with homemade strawberry ice cream for dessert.  It wasn't a day marked by the healthiest of meals, but as I've said before, executive decision making authority about what constitutes dinner is one of the few perqs of being an adult. I fell into bed and slept like the dead.

I'm glad to have gotten the jam made yesterday, when the temperature only flirted with 80 F (27 C).  Today it's going to flirt with 90 F (32 C).

Just as I was writing this post and loading the images, my husband killed a rabbit which he caught in flagrante delicto in our garden, using nothing stronger than a BB pellet gun.  I skinned it, gutted it, trimmed it, washed it, and had it inside before breakfast.  (Sorry, no pictures.  Next time.)  Since it's a wild rabbit, it's very lean and weighed in at only 1 pound, 10 ounces once reduced to the main edible portions.  It's going to be dinner, one way or the other, tonight.  Suggestions are welcome.

But for a morning and evening putter in the garden, plus dinner preparation, I'm resting today.  I may fold the mountain of clean laundry in the hampers.  I may lie under the ceiling fan and read escapist fiction most of the day.  I feel like I've earned it.