The drying of food to preserve it is an age old technique. It was traditionally done outdoors where it was easier to achieve using natural heat and air flow. This method can retain both nutrition and flavour – sometimes even intensifying it. In a modern domestic setting, this process has been mechanised with an appliance called a dehydrator which dries out food by reducing its water content.
Once food is stabilised like this, it becomes convenient: compact, easy to store, and to transport.
In the raw food world, dehydrators also act as surrogate stoves or ovens. They enable you to get a set or crisp texture with food using gentle heat (temperatures under 118 deg. F). The relatively low temperature limits damage to enzymes and other nutrients. The taste and appearance of food changes when treated like this, so it also offers variety and comfort, being similar to conventionally cooked items. Additionally, you can bulk prepare staple items, or manage a glut of fresh produce, thus saving time and money.
Dehydrators are most often box-like in appearance, with a series of sliding shelves or tiered sections. They contain a fan that warms air, and circulates it. The fan may be mounted in the base or at the rear. Dehydrators keep the food temperature low enough to retain most enzymes, whilst elevating the air temperature high enough to remove moisture at a speed that prevents the growth of mould or bacteria. The fluctuation caused by warm air being cooled by moisture as it evaporates keeps the overall temperature low until food become dry – by which time the enzymes are dormant as opposed to damaged which is what happens with regular cooking.
The low temperature settings used for raw food recipes means you don’t get instant results: 10-24 hrs are typical times (don’t be alarmed: it only uses a small amount of electricity). Normally a recipe will instruct you to use two settings: an initial higher one when food is still wet and therefore cooler, followed by a longer period at a lower one. A very low setting throughout may increase the risk of your food fermenting or spoiling.
Dehydrators are bulky items. You will need some counter space to accommodate it. They also tend to be quite noisy; rather like a microwave on both counts. Look for more compact or quieter models if these factors are going to be an issue for you.
You have a choice about capacity in terms of number of trays, so look for one that will best suit your needs. The shelved models are more versatile in terms of adjusting heights for irregular shaped items as you can simply pull ones out (but remember, this will reduce its capacity). Models with self fitting tiers are less so, although you can purchase a mix of shallow and deeper trays.
Always buy non-stick sheets because fine or wet mixtures will fall through the gaps in the wire mesh or perforated trays.
If you live in a dusty or insect-prone environment, look for a model with a fan filter which will reduce the amount of airborne particles being drawn in.
Types of food produced
- Simply dried fruit or vegetables
- Vegetable or nut pulps – once dried can be ground into flour, or stock powder
- Baked food alternatives – bread, crackers, wraps, pizza bases, tart bases
- Snacks – energy bars, and assorted crisps
- Savoury items – burgers, falafels, veggie ‘meat’, cheese with rind, crunchy garnishes
- Sweet items – biscuits, cakes, dessert casings
- Cereals – granola, buckwheaties
Dehydrated food is harder to digest than fresh because they tend dry, tend to contain more fat, and tend to be combine more complex combinations. They are good companions to fresh foods but are ultimately inferior to it so it treat them as a condiment instead of a core ingredient. Whilst dehydrators may not be essential kitchen kit for a raw foodie, it certainly extends your repertoire. It is especially useful whilst you are transitioning from a standard diet to a raw oriented one as it enable you to replicate some familiar fare. The irony is once you’ve established your raw habits, you’ll probably use it less.
1. Book into a half day class for a practical skills session and a dose of inspiration. Next one is Fri Mar 22nd
2. Susan Powers on the Rawmazing blog, 2011
3. Eben Fodor on making a solar powered dehydrator in Mother Earth News, 2006