Archive for May 27th, 2009

Food Preservation is Cool!

Sharon May 27th, 2009

Guess what’s in the Times today?  I guess I picked the right time to write _Independence Days_!  We’re trendy (at least today ;-) )!

 Check it out:


Freezing…and Why Not To

Sharon May 27th, 2009

In all the writing I’ve done about food storage, I’ve mostly left the topic of freezers alone.  This may seem strange, because freezing is the most frequently used technique of food storage in the developed world – if most people preserve at all, they often do it by freezing things.  The first is the ecological impact of encouraging people to have freezers, the second, the economic impact of relying on one.  I tend to think that other methods of storage are better choices – but it is worth asking when a freezer is a good idea.

The two major objections to a freezer are that generally speaking, food kept frozen would be better kept by other methods of preservation.  This is not true across the board, of course – for example, let’s say that you have an electric stove, coal fired electricity, and you happen to be the owner of a super-efficient sunfrost freezer, and you mostly use your freezer to preserve foods for less than 3 months – in that case, it might be more efficient to freeze. 

On the other hand, if you have a gas stove and an old freezer, the odds are good that it is almost never more efficient to freeze things than it is to can or otherwise preserve them.  As is always the case, the environmental impact of things is complex, even in and of itself. 

And the actual question of whether canned or frozen chicken is better isn’t really all the answer – there are other questions – is your freezer enabling you to cut down on other things – trips to the store, say?  If you live in a place where you can walk to shopping, it is probably more efficient not to freeze, and to let commercial freezers do the work.  If you live far from the store, the gas you save may balance out the effect.  Or, can you, as we do, use your freezer to help get rid of your fridge?  We use ice packs from our freezer to enable to turn off our fridge, making a substantial savings in wattage, since chest freezers are generally much more efficient than your average fridge.  Can you share a freezer with one or two other households?  Divided between them, it might make sense.

But I really don’t want to encourage people to go out and begin relying on freezers if they don’t already have one, simply because the cost – economically and environmentally – is so very high. Moreover, in a freezer, your food is vulnerable in ways it isn’t in any other storage method.

Statistically, even when freezers are working, more than 20% of all food put in a freezer is lost to freezer burn and decay – so freezers are already a problem – too much stuff gets buried in the back or the bottom, and wasted.  This problem can be reduced with good management, so IMHO, a commitment to a freezer means not letting things get wasted.  There’s something particularly disturbing about burning coal to preserve food, only to throw it out.  In contrast to the high rate of wastage associated with freezers (somehow people seem to think that freezing something puts it in permanent stasis, rather than merely retarding decay somewhat), home canned food gets wasted only 7% of the time. 

But moreover, freezers are vulnerable to either localized (and by localized this can be as local as “my husband accidentally kicked the cord out and we didn’t notice until it was too late) or widespread power outages.  The reality is that if you keep food in your freezer, sooner or later, you will probably have an extended power outage.  Can you afford to lose hundreds of dollars worth of food?  Only you can answer that question, but for many people, the real problem of the freezer is that you can’t afford the potential loss.

One possible way of mitigating this problem is to be good at pressure canning – if you have an alternate heat source, and are willing, when the power goes out, to spring into action to preserve anything that can be preserved, probably by pressure canning (dehydration would be great, but often when the power is out, the weather is not conducive to solar dehydration, and your electric one won’t work ;-) ).  This is a lot of work – it is our backup strategy – in our case, since most of what we store is our meat supply at the end of the butchering season, I know those chickens and turkeys will simply be canned, and am reasonably sure of not losing them. But then again, I have a wood cookstove, a supply of wood, and experience pressure canning. 

Now I like a lot of foods better frozen than other methods of preservation – but then again, I like the layered eggplant casserole at the expensive italian restaurant better than I like my own version, but life’s like that sometimes ;-) .  And since I like fresh and root cellared food even better than frozen vegetables and meat, the solution for me personally is to try more season extension, to root cellar more and better, and to grow more animal feed so that some of my chickens can be kept over the winter and butchered as needed. 

For the moment, we’re keeping the freezer, but I admit, I’m ambivalent about our own use of it (primarily to sell meat off the farm) and about recommending freezing to anyone.  Yes, if you already have a freezer, and are going to run it, you might as well run it full.  But would I recommend people go out and buy a chest freezer?  I don’t think so – too much embodied energy, too high a cost, too much dependence on fossil fuels, too many other alternatives.  I can justify ours because of our profession, and also because our net energy consumption (because we’ve been able to get rid of our fridge) is lower, but the next step is freezer-free.