Organic Hops Variety Trials and Over-wintering Study

Introduction

There is great interest among Colorado microbrewers in locally grown hops. The Colorado Department of Agriculture’s Marketing Division conducted a survey and received results from 33 of the 88 microbrewers in Colorado. Thirty of the microbrewers indicated that they would like to be able to purchase Colorado-grown hops, and over half of the surveyed microbrewers were interested in organically grown hops. There is also increasing interest among brewers to make a beer with green or “wet” hops. The production of a wet hop beer would require that the hops be at the brewery within 12 hours of harvest, which would require a local sources of hops.

There is great promise for a hops industry in Colorado. Abundant sunshine and low humidity (which can reduce disease problems) are in our favor. High winds may be a problem in open plains areas since blowing dust could contaminate the lupulin glands. It will also be important to choose varieties that overwinter well. It hasn’t been determined if buyers will require pelletized helps so processing facilities may or may not be required. Such a venture could be cooperatively owned and operated.

Due to the interest in Colorado-grown hops, the CSU Specialty Crops Program is conducting an organic hops variety trial and over-wintering study at the Horticulture Research Center (HRC) northeast of Fort Collins, Colorado. Winter hardiness, alpha and beta acid values, brewing qualities, and yield will be evaluated for several varieties of hops (see below). We hope to collaborate in the future with West Slope research stations and growers to develop baseline hop production information for that region of the state as well.

Methods

The hop rhizomes were planted on certififed organic land at the HRC on June 1, 2004, approximately 7′ apart (to keep varieties separate). Six plants each of 10 different varieties were planted for variety trials and two plants each of 4 additional varieties were planted for demonstration. Varieties were chosen based on range of alpha values, maturity times, and those commonly used by microbrewers in Colorado.

We planted “regular” rhizomes. Some companies offer larger” jumbo” rhizomes for planting. The rhizome was planted vertically with the top of the rhizome approximately 1.5″ below the soil surface. A shovel-full of composted manure was mixed in with the soil surrounding the rhizome. The hops were watered with drip irrigation.

The winter of 2005 offered temperatures consistently below freezing with several nights of below zero temperatures providing for a good test of winter hardiness. On May 25, 2005, the hops trellis was built using 14′ long 3″ diamater iron well pipe. The pipe was pounded 4′ into the ground every 20′ in row. High tensile wire was stretched on the top and bottom of the trellis. Baling twine was tied from the bottom to the top in a “v” formation to allow the bines to climb. On June 1, 2005, the plants were trimmed back to 4 main bines. Two bines were guided to each twine.

On June 22, 1-2 gallons of composted dairy manure were applied to the base of each hop plant. Leafhoppers and spider mites, common pests on hops, were present but did not merit control. No powdery mildew was observed on the plants.

Variety Descriptions

Below is a list and description of the varieties being grown for variety trials and demonstration at the HRC.

Canadian Red Vine

Cascade

Centennial

Chinook

Crystal

Mt. Hood

Nugget

Perle

Sterling

Vojvodina

Brewers Gold

Hallertauer

Liberty

Vanguard

One plant of Canadian Red Vine (consisting of four bines) was harvested this year just to get a rough idea of yield and it produced 2.18 lbs. of hops wet weight, and 0.57 lbs. dry weight.