When to harvest your hops is a tricky topic and most commercial farmers have their own special ways to determine when to harvest. In general each variety has its own harvest window; Centennial tends to be one of the first to ripen and depending on the growing season they can be ready towards the end of August here in Yakima. But the majority of varieties peak around the second or third week of September and very few are still in the ground come October.
Not only does the variety determine when it is best to harvest, but it also determines how long you have to harvest. This is commonly referred to as the harvest window and some varieties like Columbus have a notoriously short harvest window that only lasts a day or two.
Step Two: Check the lupulin glands!
The most important thing to look at to determine proper harvest date is the lupulin glands. The lupulin glands run along the middle of the hop cone and vary from light yellow to brown in color depending on maturity. Check the glands by picking a cone and rip or cut the cone lengthwise in half. Once the harvest window draws near, the glands and aromas can change daily.
Ideally, hops will be picked when the lupulin glands are fully matured (bright orange) and not overly ripe as they will tend to have unpleasant aromas of onion and garlic if left to hang too long. If you have access to a microscope that will give you an even better idea of the ripeness of the lupulin glands as they will start out perfectly round, but start looking more like a raindrop as they ripen.
Step Three: Give the cones a squeeze
Some seasoned farmers squeeze the cones and are able to tell maturity based on feel. The young cones will feel waxy, squishy, and dense, while mature cones will feel more papery and springy. The most important thing to keep in mind for harvesting is that if you like the way it smells, then you will probably still like it after you brew with it. Keep track from year to year on when you harvest and it will help you to really dial in the ideal harvest date.
Step Four: Cut down the hop bines
When it is time for you harvest, it is important to dress appropriately by not having exposed skin on your arms. Bines can be a bit mean and are notorious for cutting or scraping skin. Eye protection and leather gloves are also a good idea when harvesting.
Cut the hops and the twine just above the ground, and cut the twine from the top wire so you can lay the bine down on a table or the ground. It's helpful to have a friend for this, as the bines can get a little heavy if they're tall, and you don't want to dirty the cones up too much.
Step Five: Pick the cones
It will take awhile to pick all the cones by hand, but the only other alternative is to put in a million dollar picker, which your neighbors might not like too much.
Remove the hop cones from the bines by plucking them off by hand at the base of the cone, or using pruning shears to snip them off. Be sure to handle the cones carefully, as they can be quite fragile. If you're going to brew with them wet, putting them in a clean bucket will be fine. If you're planning on drying and storing them, we recommend putting them directly onto the screen or fabric you'll be drying them on (see below).
Once the cones are all picked you can brew with them wet for some awesome fresh hop beer, but you must use them within 24 hours or you risk them getting slimy as they start to decompose.
Step Six: Dry the hops
Drying the hop cones is a critical step in the harvesting process, as it helps to preserve the quality and flavor of the hops. Commercial kilns use high powered heaters and fans to achieve the goal of less than 10% moisture by weight. And even then it still takes 6-8 hours to properly dry them out.
Here are some more detailed instructions on how to properly dry your hop cones:
Spread them out on a clean, dry, breathable surface, such as a screen or tightly pulled fabric. A screen or mesh will allow for good airflow around the cones, which is essential for proper drying.
Place the hop cones in a cool, dry place that is protected from direct sunlight. Direct sunlight can cause the cones to lose their flavor and aroma.
Turn the hop cones over every few hours to ensure they dry evenly. This will help prevent any mold or mildew from forming on the cones.
Keep an eye on the humidity level in the room where you're drying the cones. Ideally, the humidity should be between 40% and 60%. If the humidity is too high, the cones may take longer to dry or may not dry properly.
Check the cones for dryness by gently squeezing them between your fingers. They should feel papery and dry to the touch. If they still feel moist or squishy, they need more time to dry.