Enter the Cone Zone - Builing the Hop Dryer and Oast

Hop Cones Ripening on the Bine

 In February I wrote ‘build hops dryer’ on the to-do list. Hops harvest was 6 or 7 months away, mid-August to mid-September. Plenty of time, right?  Well, in the midst of raising a market garden, attending zoning board meetings, expanding the hopsyard, and renovating old buildings, the hops dryer slipped to the back-burner. All of a sudden, August arrived. We needed that oast (hop dyer) A.S.A.P.!

An early spring and dry summer had caused the hops to sprout early and grow quickly. The harvest date came about two weeks sooner than expected. In our hopsyard, the Centennial variety is the first to bloom, and bloom they did. We estimated about 100 pounds of fresh-picked hops this year, mainly from the second-year Centennial and Cascades bines.

Fresh Picked Hops

We had learned from other growers that large piles fresh (wet) hops do not store well. A load of wet hops will actually start to compost within hours of harvest. The pile will naturally start to heat up from that reaction and spoil. The three enemies of hops (after they are picked) are heat, air and sunlight. 1) Too much heat will evaporate the some 250 essential oil compounds in the hop cones. 2) Air exposure can make them stale, and 3) sunlight exposure after picking can impart an unfortunate ‘skunky’ flavor to the cones. The best way to save hops is to dry them at low temperatures (under 100 degrees until they contain between 8-12% moisture), vacuum seal them and place them in a dark freezer.

Back in the day, hop farms had oasts, or barns especially made for drying hops. Nowadays, home growers use food dehydrators or air-dry a few pounds of hops. Modern commercial hop growers have million-dollar drying facilities and use jet engine-sized heaters to dry thousands of pounds. They deal in tons, we deal in pounds. We estimated about 200-400 pounds of wet hops in future years and needed a dryer that could accommodate those weights.

Back to early August. With harvest fast approaching, it was time to get to work and make that dryer. The resulting creation closely resembles a large, white Ikea wardrobe from the outside with surprising drying power capacity on the inside. We used melamine (coated particleboard) and drinking water-safe PVC in the construction, since they are easily cleaned and do not off-gas a smell or chemicals, like treated wood, which we did not want to transfer onto the hops.  

PVC - Easy and Clean to Work With

Bree Cutting the Screens for the Shelves

Here is the DIY breakdown of our dryer:

1. Constructed a large box and placed on coasters - dimensions 6’x4’x3’. 
2. Attached 18 PVC shelving brackets to each side of the box. 
3. Added 4 adjustable exhaust vents to the top and sides to control air flow. 
4. Attached 2 doors to the front that seal shut with piano hinges.  
5. Attached an air duct with a filter to the lower-side of the box. (The other end of the air duct attaches to the blower of a modified floor dryer.) 
6. Built 18 shelves with PVC frames and window screen mesh trays. 
7. Added wind baffles to the floor and sides to prevent air pockets. 
8. Sealed the whole box with silicone caulk
9. Placed a small space heater in front of the air intake of the blower
10. Turned it on, pressure tested it and sealed any remaining air leaks

The Finished Product

We tested the dryer with 10 pounds of fresh hops, and it worked like a champ. It dried them perfectly in about 36 hours.  Best of all, I could finally check ‘build hops dryer’ off of the to-do list, just in time for the hops harvest party! I don’t often say that something smells dreamy. But dreamy is the only way to describe the earthy and heavenly scent permeating from our new dryer when it is packed with trays of wet hops.

First Tray for Testing

Partially Loaded Hops Dryer

By harvest, we had McCollum Orchards’ first ever oast. The dryer came to be housed in the farm’s 100-year-old apple packing shed. We gave the building a thorough cleaning and fresh coat of paint. The new, bright hops dryer stands on one side of the building – representing our work toward the farm’s future. On the opposite side, it faces remnants of the wooden apple sorter and hopper used in the last century. We have to admit, after spending long we spent long hours working on the hops in there, whenever we would start to get tied, we just look across to the testament of the farm's previous era and get a little more inspiration from that long history.

Preparing the Century-old Apple Packing Shed for a New Life