Modified my food dehydrator to dry hops

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A big part of homebrewing for me is making the equipment needed to support this obsession. I have seen a lot of cool ideas on this and other forums. I figured that I would share one of mine here.

 I was given a used food dehydrator last year which I tried to use to dry my homegrown hops.  Didn't work too well.  It pushed out over 140 degrees F of heat.  My whole house smelled of hops (not really a problem except I wanted to save some of that for the beer!).  So I had to keep turning the dehydrator on and off which was a real pain and ended up not drying them fast enough anyway. I've read that 95 to 100 was a good range to dry hops reasonably quickly without blowing off too much of the lupulin.  I know that commercially, hops are dried around 130, but commercial outfits need to push product out fast and not necessarily focused on loosing some of the lupulin.  So I figured that somewhere between 95 and less than 130 would be the right answer for small scale hop drying as is the case for me.  

  Since I really didn't want to build an oast as I don't have the room for it, I decided to go another route.  I wanted to give the dehydrator another try.  Not wanting to babysit my dehydrator this coming August like I did last year, I decided to install a 600W dimmer switch into the unit.  I can now run that unit with no heat at all (just cool air) to full heat (which is what I want to avoid this year).  I'm probably going to start around 95 degrees and try batches at 5 degree increasing increments and see if I can find a sweet spot.  I'm going to weigh the hops before drying and try to get them down to about 5-10% moisture which if I remember correctly is about what you want.  My goal is to get them dry in less than a day without cooking them.

 So here's how I did it.  I took the unit apart and found that there are 3 functioning parts to the unit:  a turntable motor, a fan blower motor and the heating element.  The entire unit uses only 165W, so I knew I was safe with a 600W dimmer.  Since I didn't want to slow the turntable speed or fan speed, I installed the dimmer switch only in the heating element circuit.  There was plenty of room in my dehydrator to fit this comfortably in.  I drilled 3 holes through the bottom to accommodate the dimmer switch pin and 2 bolts to secure the switch to the unit.  Then I spliced in the hot and ground wires and put the unit back together.  Now I can just turn the knob until I have the desired temperature.

[attachment=2]Food Dehydrater 1.jpg[/attachment]

[attachment=1]Food Dehydrater 2.jpg[/attachment]

[attachment=0]Food Dehydrater 3.jpg[/attachment]

  Obviously, make sure you know something about electrical wiring before you tackle this project, and make sure you keep any wiring away from the heating element.  Although I still ran it for over an hour varying the temperature every so often to prove to myself it works and works safely, I probably will still run this unit outside on my porch this hop drying season.  That way if something catastrophic does happen, it's not in my house.  I also know that some food dehydrators do have adjustable temperature settings, so if you've got the money, it makes more sense to get one of those.  My cost for this project was about $6.00 for the switch.  I already had some extra wiring and wire nuts.  I'll post back in late summer and let you all know how it works out.
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Thanks for posting! I love hacks like this.

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Thanks, I have the same/similar dehydrator and have often made the same comments about wanting to vary the temps. I think I have the dimmer switch someplace too . . . . . .

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This is a follow-up to my post earlier this spring. Ran two small batches of hops through this modified food dehydrator at this point. If I’m drying on my porch outside on a day where the temperature varies, I find I have to tweak the dimmer switch some every once in a while, but for the most part, I can keep the temperature somewhere in between 85 and 105. So it probably averages 95 which was my target temperature. I can dry my hops in less than 24 hours this way. I might try a bit warmer, but I can definitely smell the hop aroma a lot more when it hits the upper end of the above mentioned range. So I assume if I can smell them, I’m blowing off some of those oils, and as a homebrewer, I want to minimize oil loss while still drying the hops in a reasonable amount of time. At this point, I am drying a few ounces at a time. When my nugget and Amalia cones are ready and I have to dry pounds of cones, I might find that I need to speed this process up a bit. It does seem as though this temperature range doesn’t entirely discourage all of the pests like aphids, so watch your hops closely before vacuum sealing.

Here’s a helpful hop moisture calculator from my alma mater:

https://www.uvm.edu/extension/agricultu ... scalc.html

This is factoring in someone drying a sample of their hops bone dry to figure out harvest dry matter or moisture content. I am not doing that as I am not getting enough off my 2nd year plants to do this. However, if we are to assume that our subjective analysis of ripe cones is in that 20% dry matter range (crinkly cones with some brown spots just starting to form), then all you need to do is plug in your harvest time weight and dry them until you get down to what the sample should weigh when you reach that target 8% moisture. It’s in grams, but you can plug in your weights in ounces as long as you are consistently using ounce as the unit throughout the calculator. I just picked 2.1 ounces of Williamette yesterday mid-day, threw them in the dehydrator, and they weighed 0.5 ounces first thing this morning. Don’t forget to subtract out the weight of the container your hops are being weighed in.