Tools: Dehydrators
Sharon July 10th, 2008
Ok, today’s class will focus in part on Dehydration as a strategy. I’ll post a general guide, but first I want to talk about the actual tools themselves.
There are several ways you can dehydrate food. The simplest is simply to air dry things. This works best for light, leafy things like herbs (I’ll talk more about herbs in a seperate post later today), or for things like peas, beans and grain that naturally dry on the plant. In dry climates it is often possible to dry wetter plants - tomatoes and peppers for example, by simply pulling up the plant and hanging it, but that’s not possible in humid places like the northeast.
The next simplest option is to dry with the sun. If you live in a sunny, reasonably dry place like much of the American West, you probably can simply dry things by laying food out on screens or mesh with cheesecloth over and under it (most screening is not food safe, so it is smart to put something under it) and wait until it is dry. In both the west and the east, if you have a car you can put the food in the back of the car, again covered with cheesecloth so you don’t end up with thousands of bugs in your car, crack the windows for some ventilation, and come back to dried food. Some people worry about the outgassing issues, here, but honestly, I think if you actually ride in your car you will get far more exposure to outgassing than you will through the food.
If you live in a humid climate, you’ll probably find that food will mold faster than you can dry it most of the time. Blue and furry food is not desirable ;-), so you need something that will work better. Ours is modelled on this (btw, their whole site is wonderful and has tons of useful sustainability information from people who really are living the life), and works very well. We use black polyester fabric, and I use plastic mesh polypropolene screens from my electric dehydrator, rather than what they recommend (polypropolene does not contain bisphenol-a). Ours is way too small, and we’re planning a much bigger one soon.
The next easiest way to dry is to use a heat source that’s already going - some people dehydrate in their gas ovens with their pilot light on - I think the success of this depends a lot on how humid your climate is - I’ve heard of people doing it successfully and of people having problems. If you use a woodstove, you can dehydrate on screens placed near (not too near - you don’t want to cook the food) the stove, and if you have an earth oven, you can use it to dehydrate when it gets to the lower end of the temperature range.
It is worth stopping for a minute here to talk about temperature - most foods are most nutritious if they are dehydrated at the lowest possible temperatures. Herbs and greens can lose most of their value if they are dehydrated much above air temperature at all - you generally don’t want to them too warm. And with every food, you want to use the lowest acceptable temperature, because dehydrating already loses a fair bit of nutritional value. So you do want to be careful with oven drying of any sort - yes, you can do it, but it can be hard to keep temperatures low enough for the food to be nutritious (more about dehydration and nutrition in my general guide) as well as good tasting. The same issue occurs with solar dehydrating - if your car gets up to 200 degrees, that’s fine for beef jerky and it may not be much of an issue for tomatoes, but you do not want to put medicinal herbs, greens or berries like blueberries, elderberries or cranberries in there, since so much of their value is located in their nutrition. Dehydration is easy, but it does take some care, and you want to use the right temperature for the right food - so maybe do the berries on an overcast day.
Finally, there is electric dehydration. This is useful for people like me who have a limited period when solar dehydration is even possible - but who still have crops coming in during the other periods. Basically, it is a set of stacked trays with a heating element. and (sometimes) a fan. If you live in a dry, warm place, you probably don’t need one at all - you might as well take advantage of the sun. In a cooler place, if you are content to be done dehydrating in September and October, you’d also be fine without one. On the other hand, electric dehydrators are convenient, and they are the sort of thing that shows up on Craigslist and freecycle and at garage sales.
If you buy a used one, you probably will end up with one of the low end plastic models. Depending on how much you care about this, you’ll definitely be putting your food in contact with polycarbonate, which means bisphenol-a. This is something to think about, but may or may not be a major concern. I’ve had two of these, all from yard sales - one American Harvest and one Ronco - and they all work. The Ronco gets the best reviews of the bunch, but I’ve met people who like almost all of them. They use more electricity than the upper end ones, sometimes overheat things, and can take a while, but they aren’t bad tools. For $5 at a yard sale, there’s only so much complaining you can do. If you have a choice, you do want one with a fan, not just a heating element, because you’ll get much more even dehydration, and fewer hot spots.
Most of these retail for between 35 and 60 dollars. I would tend to bet that most of you could find a used one, though. If you do buy used, do make a quick check of the produce recall lists for the brand you buy - one older American Harvest model was recalled because the heating unit caused a fire. They are generally perfectly safe to use unattended, though.
There are a few more expensive, higher-end models, usually made by the same people (not always - Vita Mix has one) - I have not tried any of these. When I do reviews, I generally try to try a range of things, and go around borrowing - in this case, I very pointedly didn’t bother. And the reason I didn’t bother is this - every single review I’ve read and everyone I’ve talked to says that if you are going to spend a good chunk of money on a dehydrator - for example, if you have a bunch of fruit trees, or a large garden and dehydrate a lot - buy an Excalibur. And I’m going to go with that.
That is, the lower end electric models are adequate to their purpose - particularly if you are getting them for $5 - but even at $35, they aren’t bad tools. But if you are going to spend over $100 on a dehydrator, get the good one - get an Excalibur. I simply don’t think there’s enough evidence that any of the mid-range options are good enough to bother with - spend the money making a good solar one instead.
Eric gave me an Excalibur for my birthday last year, and it is really, really a good tool. It has multiple heat settings (and it actually keeps in that range, unlike any of the other cheapies), it dries quickly, it uses less electricity than anything else and has a huge amount of internal drying space. Lehmans sells it (one of the few electric tools they do sell), and it is *not cheap* (I was stunned that I got such a fancy birthday gift - not our usual thing). It is also a superb piece of equipment - among other things, the drying screens are polypropolene, so they don’t produce bisphenol-a, and the quality is very, very high. I know people who have had them for more than a decade with no problems.
But please understand me - my suggestion is not that anyone should break their budget on an expensive dehydrator - if money is an issue, you can get along very well with a solar dehydrator, your car, the sun alone, or those plus a cheapie from a garage sale. But if you have a lot of dehydrating to do, and a budget that can stretch that far, and if you live in a climate where solar dehydrating is a very short season (sun is always better than electricity), then I’d recommend the Excalibur wholeheartedly.
Ok, on to techniques.
Sharon
sharonastyk.com |
