Sunday, June 20, 2010

Food Storage - Dehydrators

This is not a food blog, but a DIY blog, mostly.  As we continue to see signs that the economy is getting worse, supplies are becoming limited, and things in the future may not as be cheap and convenient as the past, it seems good to me to turn our attention to the well being of our families.  Some religions, I understand, teach long term food storage as a preparation for certain prophetic events.  I'm a Baptist, and the only prophetic event we generally look forward to is the Rapture, which means material needs will not apply.  But, I don't have any doubt things could get much much worse before they get to be on par with the end times discussed in scripture.  
With that in mind, I began my investigation into food dehydration this afternoon.  I found many good resources which appear below.

First, you'll want some general information, hints and tips from an experienced food dehydrator.  Dehydrate2Store has a lot of good information.  There are videos, recipes, hints and tips and apparently an avid following.  The biggest value on this site (to my eye) was the tips section.  I printed and filed that.

There are apparently a number of different dehydrators commercially available on the internet.  Some people say they all amount to plastic boxes with fans.  Some people swear by electric, some swear by solar only.  A few things ran common, however.  Any unit worth the money or time to construct will be made out of food grade materials wherever the food or drying air will be circulating.  Lots of materials you might think are good for a DIY version are actually stabilized with chemicals you do not want leaching into your food.  Good old standards like Stainless Steel mesh, glass and untreated wood seem to be the best and safest components.

There are a lot of plans out there.  I found two that I tucked away for a future endeavor.  This one uses just glass, black painted metal, screen and solar power.  It appeals to me for the simplicity and lack of moving parts.  The main draw backs are a dependence on sunlight and a lack of good temperature control.  Dehydrate2store recommends 120 - 125 F.  Most sites agree that much over 130 and you are cooking your food instead of drying it, which can give you a cooked flavor in your dried goods rather than a fresh flavor.  The lower slower temperature preserves the most flavor.

Alton Brown has a lot of good tips and a humorous presentation style.  He talks about energy efficiency, food flavor and practicality.  He also offers a good tip for food prep - lemon juice cut with water as a pre soak to kill bacteria and pathogens and help the food retain better food and color longer.

On the energy efficiency side, there are some folks that like to use light bulbs, and some that suggest you get a gecko warming ceramic element (like Alton does).  To my mind, anything electric means more of the stuff that seems to be going up in cost about 9% per month here.  I'm thinking it won't be long before deep cycle batteries and a hand full of cheap solar panels will be very cost effective.

But I digress.   If you are going to go electric, it seems that ceramic is the best heating element.  Light bulbs produce light and heat and the light isn't strictly useful for drying food and in fact can degrade photo sensitive nutrients.  If you do use a light bulb, make sure it actually produces heat.  CFLs don't produce as much as incandescent, and halogens produce massive heat.  Which brings me back to the temperature control I mentioned earlier.

Temperature control is important in any configuration you use.  Alton and other suggest using a kitchen thermometer.  A cheap meat and poultry thermometer might do just fine.  If you don't have a variable and controllable heat source, you will need a variable and controllable heat exhaust or cool air intermix feature on whatever you build.

My thought for this is if I go solar, I would want to have a sliding slat behind the air inlet holes.  Reducing air flow by sliding the slat over more holes would increase the temperature.  Opening more inlets would allow more cool air into the dehydrator, increase air flow and lower the temperature.  This is strictly a manual, low tech approach that would require some pretty constant monitoring on partly cloudy days.  A mechanical thermostat would be a good way to automate this.  Old thermostat controls (non digital) have bi-metal springs that could be useful here.

So, I think this is definitely on my list of things to do, along with continuing the expansion of my cultivated area in the garden.  The more food I can produce and dry, the more we have that is ready (even out of season) in the winter.  Ultimately, I would need to produce and dry several tens of bushels of food per summer to feed us through the winter and would need to supplement with hunting.  Hopefully, things don't get bad so quickly that I run out of time to ramp up our capacity here.   Cheery thoughts, no?  Chin up - humans are one of the most tenacious and adaptable creatures on the planet.  Little adventures like this will make it all the more enjoyable when hard times do set in.