A hint of hop history
Hops likely were originally native to Asia and later were cultivated by the Greeks and Romans for their tender shoots that were cooked and eaten much like asparagus. However, the dried cones were not used for bittering and flavoring beer until the Middle Ages, and it was only in the late 1500s that they came into regular use in England.
Today, commercial hop cultivation in the United States is centered in the Yakima valley of central Washington and to some extent in the Willamette valley of Oregon. There is also some acreage in Idaho. Historical hop growing regions also have included California, central Wisconsin, central New York and western Massachusetts. In fact, hops have been raised commercially throughout most of Europe and North America, and homebrewers now successfully grow them in every US state and Canadian province.
What it takes
The requirements for growing hop plants include well-drained soil, sufficient moisture, a sunny location, room for the foliage to climb and trail and a growing season of at least 90 days without a hard freeze. The roots also like a dormant season and will withstand harsh winters. But this does not mean you shouldn’t try growing them even if you live in frost-free Hawaii or south Florida, and some of the valleys of southern Alaska are temperate enough to produce hops during the long daylight hours of the summer.
The bines — technically differentiated from vines because they twine in a clockwise direction — are annual, dying off each winter. The roots, however, are perennial — sending up new green shoots in the early spring. Over several seasons, the plants develop an extensive root structure and grow best in a fairly large space, but there are those who manage to raise hops in fertilized large tubs on a sunny deck. Surplus beer kegs will work if they have holes for adequate drainage.
Only the female hop plants produce the distinctive cones, technically known as strobiles, that are used in brewing. The presence of male plants will cause the production of seeds that reduce the bittering and the useful yield. This is why digging up and replanting of wild hops is not recommended. Buy female plants that have been selected for cultivation.
Where to go
Many homebrew shops and online suppliers offer hop rhizomes for sale in late winter or early spring. Rhizomes are thickened, root-like sections about the size of a finger that look somewhat like small sweet potatoes. Check for availability at this time of year. (If your local homebrewshop doesn’t carry rhizomes, see the sidebar on page 45 for a list of internet suppliers.) Rhizomes are stored in a cool location, often refrigerated.
The varieties offered for sale may vary somewhat from year to year, depending on availability and disease restrictions. Not all of them will do equally well in a particular region or location. If you have hop-growing members in your homebrew club, they will likely have some information on what has worked well or poorly in your region.
Among the most successful for homebrewers are commercial varieties developed in North America. These include Willamette, Mt. Hood, Chinook and especially Cascade, which are prolific and reliably produce high yields almost everywhere. Other varieties have mixed results, but you are free to try them. Keep in mind that when English or German hops are grown in the US, their character changes.
Hops spring eternal
Hops are an early season crop and can be planted soon after the soil can be worked. This likely will be anywhere from early February to mid-May depending on your location. If you are an experienced gardener, you can think of them as being similar to peas in terms of their planting time. They will tolerate moderate frosts well, although a hard freeze — below 28 °F (-3 °C) for 24 hours or more — will damage the young shoots.
Location, Location, Location
Choose a sunny spot with good drainage. You will later need strings or wires for the bines to twine around as they grow. These can be stretched from stakes in the ground to tall poles or the edge of a building, ideally the south-facing side.
Hops are prolific climbers; they can reach a height of 25 to 30 feet (8–10 meters). However, they can be trained to grow vertically for part of that distance and then extended horizontally or at an angle along an elevated trellis or lattice. It’s worth planning for the best configuration that fits your growing space.
The soil should be porous and relatively rich. Till it to a depth of about 12 inches (30 cm), adding a little sand if it is overly dense. Dig holes about 10 inches (25 cm) deep and 24 to 36 inches (60–90 cm) apart, so that the plants don’t grow together. In the bottom of each hole place an inch or two (3–5 cm) of organic compost or a balanced, mild commercial vegetable fertilizer or well-seasoned manure, then set a rhizome with any rootlets pointing downward. Fill the hole the rest of the way with soil, tamp it down lightly and cover with some mulch such as straw or grass clippings. Water well but do not flood the ground.
Growth and Maintenance
Within a couple of weeks, depending on the soil temperature, the shoots should begin to emerge. It’s best to select the three or four strongest shoots from each plant and trim back the others. Once they reach a length of 12 to 18 inches (30–45 cm), twine the shoots in a clockwise direction around the wires or strings and let them climb. On a warm, sunny day in late spring, it’s not uncommon for them to grow 6 inches (15 cm).
The plants will require fairly frequent watering throughout most of the growing season, although the ground should not have standing water. If you are in a dry climate you should probably consider drip irrigation or a soil soaker. In order to prevent mildew — a common problem plagueing hops — do not drench the foliage.
Hops have a few enemies, animals that enjoy hops as much as the most rabid IPA fan. Rabbits and deer are fond of the young and tender shoots; you may wish to protect the plants with chicken wire when they are small.
Bothersome insects include aphids, spider mites and Japanese beetles. Because you will be brewing with the cones, use low-toxicity measures to control pests. Ladybugs (available at some garden shops) are a natural predator of aphids, while mild insecticidal soap sprays are the best defense against serious infestations of the others. Generally these problems become less severe as the season progresses.
After the summer solstice, the plants gradually will switch their energies from growing foliage to producing small, burr-like flowers and eventually the cones. These will continue to appear and grow throughout the summer. The number of cones your bines develop will depend on the age of the plants and the growing conditions. Don’t despair if you have few or even no cones in the first season. Almost all hop growers report much higher yields after a year or two as the plants develop a more extensive root system.
Bringing in the cones
Typically by late August or early September, a bit earlier in warmer climates, the first cones will be ready for harvesting. It’s a little tricky to determine when hop cones are ready to be harvested, but here are a few tips:
Color: The color of a mature cone should be a light yellowish-green and the individual “leaves,” technically known as bracts and bracteoles, should be starting to separate.
Lupulin Glands: There should be dots of powdery yellow lupulin glands on the bracts toward the stem.
Touch Test: When you squeeze a cone it should feel slightly dry and papery and spring back a little after you release it. If it is somewhat moist, dense and unyielding, it is not ready. After touching a ripe cone your fingers should have a little lupulin and a resiny, flowery, citrusy or piney smell typical of hops.
The cones mature over a period of a couple of weeks, so you can harvest them progressively. If you do this you will need a ladder or other means in order to pick only the ripe cones. Be careful to avoid falling; it’s best not to have a homebrew before or during climbing. The alternative is to cut the strings or wires and lower them to where they can be reached. Unfortunately this may require discarding some of the cones that have not yet ripened.
Drying the cones
The harvested cones still need to be dried. There are several ways of accomplishing this. A food dehydrator works well, as does a cookie sheet in an oven set to no warmer than 150 °F (65 °C). Leave the oven door open and provide good ventilation. It will take the better part of a day. A slower but often more convenient method is to find a warm, dry location such as an attic or garage. Spread out the cones on a window screen supported by sawhorses, with a fan set on the floor underneath. The cones should be dry within 2–3 days if the temperature stays mostly above 85 °F (30 °C).
When the cones are dry they will still be light yellowish-green in color, but they will feel brittle and papery and be a fraction of their weight when picked, due to the loss of moisture. At this point place them in zippered plastic bags intended for freezing, squeeze out as much of the air as possible, label them and store in the freezer until ready for brewing.
The bines will wither and die off after the harvest. Cut back the dead foliage in the fall to within about an inch (3 cm) of the ground. It can be composted with other yard wastes; some people make hop wreaths for the winter holidays. Place some straw or other mulch over the plants before the ground freezes or goes dormant. This is also the best time to fertilize the soil. The roots will send up shoots again in the spring.
If you wish to replant the hops in another location or donate some of them to your fellow homebrewers, you should dig up the rhizomes in the late fall. Select and cut healthy-looking sections about as thick and slightly longer than your finger. Surround each one with a little damp soil and mulch, and place in a zippered plastic storage bag. Store in a dark, cool location such as a basement or refrigerator. They can be planted again in the early spring.
Commercial hops are analyzed for the alpha acid percentage so that the brewer knows their expected contribution in terms of bittering. Unfortunately it’s difficult for the home hop grower and homebrewer to determine this without access to a well-equipped biotech or medical lab. You can estimate the bittering based on the published alpha acid ratings of commercial hops of the same variety, but these vary from season to season. Your homegrown hops are likely to be higher or lower, depending on your location, the weather and the care you lavish on them.
It’s possible to brew a test batch of beer with homegrown hops and then compare it to other beers of known bittering. By this means and with a little calculation (brewing software is helpful for this task) you can approximate the alpha acid content. However, the precision will depend on your taste buds, which are notoriously inexact for such purposes, as well as the timing of the hop additions in both the test batch and the beer to which it’s being compared. You can also send a sample of your hops or the beer brewed with them to a commercial laboratory for alpha acid or bittering analysis. The fees for such services are generally in the range of $25–$50.
As a result, many homebrewers use homegrown hops only for flavor and aroma additions, where the bittering is less of a factor and the fresh qualities of your own hops are far more important and appreciated.