How We Harvest Hops
Because of the scale of our production, we made a decision to go with tried and true methods for harvesting at our scale. This search led us to the Eden of hop growing… Germany. While Germany and the US Pacific Northwest produce close to the same volume of hops annually, there are around 50 farms on the US side and 300 farms on the German side. Germany, with its more numerous smaller farms, has long sought after higher efficiency of equipment to preserve their ability to grow hops. This was the perfect fit for our operation and so in 2017, we began the task of importing equipment and building our Hybrid American-German harvest facility.
Soller Hop Wagon– Our German hop wagon and bine loading arm comprise the first leg of the harvesting journey for our hops. This system allows us to gently and efficiently transport the bines out of the field and back to the picker in the hop barn.
This system cuts the bottom of the bine and carries the bottom of the plant to the gripping wheel at the back and top of the bine arm. This wheel rotates slowly to allow the bine to be stretched and for the string at the top, near the wire, to break off and float into the wagon behind the tractor. This happens at about 2 bines per second and at this speed, the wagon can fill with mature bines in a couple of minutes. It is then ready to head up to the hop barn and get picked.
Wolf WHE 513- Once the bines arrive at the hop barn they are unloaded out of the wagon on either side of the Wolf feed arm to then be loaded onto the feed chain and taken through the picker. As the bine is pulled through the machine, it passes between a series of drums with “fingers” that pluck the hop cones and also leaves off the bine. The shape of the finger is very important so as to not damage the hop cones as they pass through. After the bine is completely cleaned, the bine exits the picking section and enters the chopper. The stalk of the plant is chopped up and blown into the silage wagon so that it can be composted and returned to the field to deposit nutrients and organic matter back into the soil.
After the cones and leaves are separated from the bine, they are conveyed to a set of pre-sorting belts to remove the cleanest hops and then to an air classifier. The large tubes on either side of the Wolf contain fans that create negative air pressure and cause leaves and any stems to stick to a rolling screen and are taken back to the chopper. The hops are then sent over two sets of dribble belts that are set at an angle to allow the hops to roll down and any remaining leaf and stem material to roll up and be sent to the chopper. Cleaned hops are then conveyed out the side of the picker and up a long conveyor to the green hop silo.
Green Hop Silo– After leaving the picker the hops are ready for the drier but the drier may not be ready for them. That’s where the GHS comes in. It’s simply a protected place for the hops to wait for a drier level to become available. Once hops are harvested however they immediately start to give off moisture and, if piled too deep, could start to degrade. So before the hops enter the silo they land on a traveling conveyor that lays the hops across the length of the silo so as to allow adequate airflow around the hops. This conveyor also allows us to pull wet hops off of the picker to be sent to brewers and used as wet hops in harvest beers!
The Hop Drier (Hop Kiln)– This is the heart of our building, the most complex, and also central to providing a perfect end product to our brewers.
Once the top of the Hop Drier is ready to be filled, the Filling System “calls” for hops and the door on the end of the silo opens. The floor of the silo moves the hops to the door and onto conveyors that transfer the wet hops up to the Filling System. The Filling System is probably the hardest part to explain with words so we included this video so you can see it in action.
For proper drying, the hops need to be laid in a consistent layer that is of a certain depth depending on hop variety and weather conditions. Our beds are kept between 12-18 inches to allow plenty of airflow through the hops. Our Hop Drier has 3 layers. As the hops drop in moisture the hops can be moved to the next level below via the floor being louvered. We open the floor and the hops drop to the next level. This also mixes the hops slightly to allow for more even drying as well.
The air and heat to dry the hops are provided by 2-30hp shock-isolated fans and a 5 million BTU/hr burner. Numerous sensors are stationed through the drier. These monitor and control airspeed, temperature, and humidity and make sure we dry the hops to the correct moisture without going too low which can lead to cone shatter and also dropped lupulin.
The bottom (3rd) level in the drier is also a drawer. Once the hops hit the correct moisture, the door opens and the drawer moves out of the drier. Once the drawer completely exits the drier, the door shuts and the other two layers continue drying. At this stage, we complete a series of moisture readings on the bed and if everything looks good, the hops can be moved on to conditioning. If for some reason the hops still need a little more drying time they can still be moved back into the drier until they are ready.
Hop Conditioning– Hop conditioning starts after the hops come out of the drier and are at the correct moisture. You might think that since the hops are now at the correct moisture they can go directly into the bale and into the cooler. However, because of the shape of the hop cone and the variations of that shape, the hops need a cool-down period as well as time for the moisture to equalize in the cone. While a cone may feel dry on the outside, the internal stem called a string, may still be 4-8% higher than the outside of the cone. Farms out west compensate for this by drying the hops down beyond the percent of moisture they want and then letting them come back up to moisture while conditioning. This does help them move through the conditioning phase much quicker, however, there can be some issues with reduced quality and they have no room for error. If there is a mistake it must be blended out in the pelleting process.
We have 3 conditioning boxes that allow us the flexibility during harvest to separate varieties, separate different lots of the same variety, and allow other farms to bring us their product to dry and condition as well. Another rolling conveyor, slightly wider than the drawer, catches the hops when the louvers open on the drawer in a beautiful cascade of hops. This moving conveyor is similar to the conveyor on the hop silo but larger and travels along the top of the 3 boxes. Once the correct box is selected for the hops to condition in, the rolling conveyor travels to the edge of the selected box, the conveyors start to turn and the box moves forward and the hops make another beautiful waterfall into the conditioning box.
What makes this conditioning system unique is that each box is connected to the Wolf ConAqua System. This is able to circulate air through each of the boxes to help in the conditioning as well as allow us to make adjustments with a mixture of warm, cool, dry, or moist air to zero in on the perfect moisture percentage so that storage and later processing goes smoothly and all available aroma and flavor compounds stay in the hops.
Hop Baling– Packing the dried hop cones into bales is the final step. For our operation, we stuck to the German method and use a Reith Hop Baler Type 3000. This has two bale tubs to allow one bale to be pressed while the other side is being sewn, removed, a new bag prepped, and then ready for the next bale to be made.
Once a conditioning box has been tested for correct moisture and has been given the go-ahead to be baled, the door side of the box is opened and the hops move toward the conveyor at the end of the box. The conveyors transfer the hops up the incline and into the top of the baler. The Reith baler functions as a giant scale. Each foot of the baler has load cells that constantly measure the weight of the hops as they are loaded. Each variety has its own program and once the hops fill the tube they are compressed down into the lower tub that holds the bale bag. A standard European bale weighs between 65- 75kg (143-165lb) and is about the size of a regular hay bale. 2ft x 2ft x 4ft.
Once the bale is finished the tub containing it moves out from the press, the empty bag on the other side moves in to start baling and the completed bale is sewed shut on top using poly string. The bale is then taken to the scale, it is weighed, labeled and its information is recorded in the bale log so that we can track that bale through processing to pellets and eventually to the customer. Once 6 bales are stacked on a pallet, the pallet is transferred to the cooler and stored at 36F to await pelleting once winter sets in.