Harvesting, drying, and processing your hops
By Steve Miller
It’s nearing that time and with all of the work you have done so far, it is very important to do things right to maintain quality. Here is a check- list and some things to help with keeping the quality where it should be. Brewers want and deserve the best product you can supply. Brewers expect your hops to have a quality analysis done for alpha, beta, HSI, and total oils. This is extremely important
1. Make sure all harvest, picking and drying equipment is in good working order and clean. Hops are a food product, not hay! No birds or rodents in drying or picking areas. To package your hops you will need a 20-C license from NYS Department of Ag and Markets for vacuum sealing. You will also need an additional schedule which I can send you from the Geneva Food Venture Center.
2. Make sure you have all of the equipment you need to determine harvest timing (i.e. Scale calculator, UVM on line dry matter/moisture calculation tables.)
3. Start testing some samples for dry matter. They will gradually increase from 15% percent or so to 20% to 22% to 24% Many aroma varieties should be in this 22-24% range when harvested.
4. If you let them mature too much they may brown, but even more important they will begin to dry so much that the cones will shatter when run through a picker.
5. Have a notebook for records, and use it!
6. Do not cut more than you can handle through your dryer as this can lead to poor quality very quickly. Hops should be in the dryer ideally within a half hour of cutting the bine, but not more than a couple hours especially if it is hot. Keep the cut bines out of the sun.
7. Hops degrade with heat, sun and oxygen so everything you do should keep these factors in mind. Keep dryer air under 130F, lower is better but relative humidity may call for more heat to prevent molding. Dry hops that have lost some oil content are better than moldy hops.
Once you start drying you can use a moisture meter to determine when they are done. Hops should be in the 9-10% moisture range to be stable for storage. Anything above 12% will likely mold. Most moisture meters only operate between 7 and 14%, which is why you need a scale.
8. Hops should be laid onto the kiln floor from 4-20 inches deep. Use as much air as is possible without the air punching a hole through the hops. As the hops dry they become lighter so open holes let air escape without going through the pile evenly. One trick is to use bird netting placed on top of the hops in the kiln to keep these holes from developing. You may need to experiment with this.
9. Moisture meters are calibrated to have the probe go into densely packed hops. If they are not dense it will give you a false reading. The strig will hold much more moisture than the bracts and this too can make it seem like the hops are ready. It is a good idea to let the hops condition at least for a short time and retest. Out West where they use a lot of heat and the kilns are filled deeper, they will condition even over night. Baled hops that have too much moisture will not only mold but can spontaneously combust.
10. To obtain a more accurate reading with the probe, try using a home made compactor. This one is made from a caulking gun and Michael Roy gave us this tip on his recent visit to New York. The probe goes into a small hole at the far end of this PVC capped pipe. This one is mechanical, pneumatic guns are also available.
11. Dried hops should be baled right away and stored in food grade plastic mesh bags at 34-40 degrees F. Do not store hops in coolers with produce that gives off moisture or ethylene, or any other product that could contaminate the hops.