The Art of Hop Selection One Brewers Opinion

The Art of Hop Selection – One Brewer’s Opinion Daniel Carey New Glarus Brewing Company February 29, 2020

QUALITY The Life Of A Hop Bale HARVEST DRYING STORAGE PELLETING STORAGE BREWING

What is HSI? Developed in the early 1970’s by two USDA Scientists (Tax Dollars! ), Gail Nickerson and Sam Likens Developed before hops were pelletized. The original purpose was to assess bale quality Mistreated hops produce a lingering bitterness, poor aroma and inferior foam Understanding the importance of the Hop Storage Index by Rob Sirrine, Michigan State University https: //www. canr. msu. edu/news/understanding-the-importance-of-the-hop-storage-index “The Hop Storage Index (aka “HSI”) is a measure of the degradation of alpha and beta acids during storage and handling of hops. As hops age, are mishandled or improperly stored, the levels of specific compounds within the hops change. Acids tend to decrease over time, while derivative compounds associated with oxidation increase. During spectrophotometric analysis of hops, acids and degradative compounds can be detected because they absorb light at different wavelengths. Hop acids absorb light at 325 nm and degradative compounds associated with oxidation absorb light near 275 nm. Hop degradation coincides with a progressive increase in the ratio of absorbance of hop extract at these wavelengths of light. The HSI is calculated by dividing the absorption of hop extract at the two different wavelengths. Oxidation compounds = Absorbance @ 275 nm Acids Absorbance @ 325 nm As hops quality deteriorates the HSI increases. HSI is cultivar dependent and can vary year to year. HSI is a useful indicator of hop quality for growers and brewers. Measuring the HSI at harvest and after processing prior to use, can provide brewers with information on the freshness of hops. ”

What is a Good HSI Value? < 0. 20 is too low Typical industrial norm in PNW = 0. 22 to 0. 28 If > > 0. 35 = cheesy flavor Best HSI results when hops are harvested at optimum time, with lower stripper speed, controlled drying and baling, low temperature pelleting and cold storage at all times

A Theory as to why Traditional European Noble Hops sometimes yield higher HSI? HSI based a Ratio Oxidized Products + iso alpha acids + Other Hop Compounds Mostly Alpha and Beta Acids Traditional European Nobel Hops have low alpha content compared to modern US types. Plus they can contain higher levels of “Other Hop Compounds”. Thus they can trend toward higher HIS. Therefore, I look more at the “Delta” across processing and not the absolute value Based on Personal Discussions with Adrian Forster

When to Harvest? Correct Harvest Date Based on past history. Climate variability! Moisture, of course HSI 0. 22 – 0. 28. Depends on variety!! Balance of fine cone appearance, aroma, and acids Too Early Low HSI. For example << 0. 20 Immature Cones = Low Impact Dull aroma and Low Bitterness Too Late High HSI > 0. 35 but depends on variety!! Harsh Bitterness. Oxidation of acids Onion/Garlic Aroma Browning of cones. Less “curb appeal” More impactful aroma that is preferred by some brewers Know your varieties and you customers! Higher HSI at Harvest leads to greater degradation in storage

An Example of a “Picking Index” Picking Index = (HSI x 100) + Dry Matter For example = 45 – 52 for Bravo at Roy Farms “Frequently in the hop world the question of “when to pick” comes up. I think it is an important question if we are looking for constancy and quality in our product. From a growers perspective, guidelines for picking must be simple, affordable and easily implemented. There a multitude of variables that impact quality and consistency and I believe that our “pick index” program works well for us. Since most growers do look at Dry Matter we tried to see what we could do with the sample at the same time. Sample prep for dry matter is no different than sample prep for UV Spectro. For us the most informative info derived from UV Spectro is HSI. Additionally HSI is the only qualitative data available pre harvest to most growers. ” Jim Boyd, Roy Farms, Washington

Hop Drying “All too often, improper drying & baling of hops turns good hops in the field into a nearly useless product. Over-drying of hops will not only result in cones that break apart during baling (causing accelerated aging), but also will evaporate much of the hop oil”. Val Peacock 8 – 12% moisture Take care to avoid pick up of off aromas from smoke, auto fumes etc Over Drying = loss of aroma and bitterness quality. Development of onion/garlic flavor Under drying = spoilage due to microbiological attack. At center of bale. Fire!? Pacific Northwest dryer Inlet Temperatures < 145 °F Best farms ≤ 130˚F (125 °F with 26 – 30” bed) 6 – 8 hour drying. Germany maximum is 144˚F for aroma hops and 149˚F for high alpha hops. Three level tower dryers with 12 – 15” bed. 4 - 6 hour drying. Why so hot? To allow for higher throughput but quality suffers. Air Speed and Evaporative Cooling. Loss of aromatic oils and alpha acid increases at higher temperature. Temperature versus time.

Ambient Drying • Your secret weapon! A quality and marketing advantage • You can do it because you have time. You are not “Dryer Constrained” like your competition • A Gentle process with Minimal impact on HSI • Bigger “window” to reach proper moisture • More even treatment across bed. < 1% moisture delta! • Less cone shatter. No need to disturb bed! • Preservation of Aroma and Bitterness

Hop Bale Material of Choice? Plastic Cardboard Burlap Polypropylene

Bale Compression US Norm 155 – 160 kg/m 3 5 – 10% crushed Lupulin German Norm for RB 60 bales 100 – 150 kg/m 3 2 – 3% crushed Lupulin

Bale Storage Each variety has a unique Storage Stability Storage Temperature - Bales at < 37 °F is best but standard in Europe is ≤ 5 °C (41 °F) Don’t store with other materials. Off aroma pick up Away from doors / drafts On pallets / off floor Pelletize ASAP during cold weather to stabilize rate of deterioration

Relative Humidity for Bale Storage? “There was some agricultural product storage research done a while back having to do with what relative humidity level of a storage room will maintain the desired moisture level of the product. For example, for hops at 9% moisture content, a relative humidity of 62% maintains the 9% hop moisture content (doesn’t dry out the hops, nor does it raise the moisture content). At 8% hop moisture, it goes to 55% relative humidity, and at 10% hop moisture… 68% relative humidity. ” Jim Solberg Indie Hops 60 – 80% Relatively Humidity is recommended by Val Peacock

Who do I select a lot of whole cone hops? Are the cones intact or broken up? Are they Green or Brown? Brown on exterior only = wind or mechanical damage Brown to center = disease Leave and Stem content? Mold? Aphids, Downy Mildew, Powdery Mildew. Especially important if hops used for Dry Hopping! Rub vigorously to break lupulin. Moisture Content Is aroma typical? How intense? Off aromas?

What can compromise quality? Hop pest and disease damage Mechanical damage from field or processing (hop conveying!) Weather or wind damage Harvesting too early or too late Improper harvesting Improper drying Improper baling Mechanical Damage Contamination with non-hop materials or odors

Pelletizing Table Stakes - Page 1 Pelletizing is not easy! Hops have a mind of their own! A terrible thing to do to hops! Pelletizing ruptures the lupulin glands exposing them to oxidation and volatilization. Need to get hops into an inert atmosphere as soon as possible Split open bale before “Bale Breaker” to see if hops are spoiled or contaminated internally Heat develops in hammer mill and especially pellet press due to friction. Worst with low alpha hops. Max Temp of Pellets Exiting Pellet Press ≤ 55°C (131 °F) for aroma hops which is too hot Tenacious Badger @ 41 – 43 °C (106 - 110 °F). The best results I’ve ever seen!! It is acceptable to use Liquid Nitrogen Cooling at Press but plant must achieve proper temperature measured out of Pellet Press without artificial cooling

Pelletizing Table Stakes - Page 2 Remove and discard Breakout Pellets (e. g. glassy or scorched pellets) at start up. Scorched or glassy pellets should not be feed back into the pellet stream. Cool pellets to < 25°C (77 °F) within 20 minutes of pelletizing Pellet density not to exceed 550 gms/liter. 485 gms/liter is optimum. But means a larger box Tenacious Badger @ 485 gms/liter. Great Work. The best results I’ve ever seen!! Larger particles at hammer mill. Dusting is not a problem for craft brewers Foil Integrity Maximum O 2 Concentration in Foil Immediately After Sealing < 2. 5% But the foil seal is, by far, the critical criteria! Leak test foils by submerging in water to detect bubbles/leaks. Must be moved to Cold Store at ≤ 40 °F as soon as possible but less than 12 hours after packaging Check HSI before and after pelletizing HSI increase across pelletizing should be < 0. 05. Best if ≤ 0. 015

Other Considerations Pesticides Nitrates Glyphosates

Pesticides No MRL’s (Maximum Residual Levels) for pesticides in beer. As long as MRLs are not exceeded in hops, there are no health concerns for beer consumption. None the less, the court of public opinion holds sway Detection limits of pesticides in beer are being lowered with refined testing Pesticides in hops can be detected in beer especially in strongly hopped beers. This correlates with residues in hops and their solubility in beer. Hops fall under pesticide regulations like all crops and require that the grower possess a pesticide applicator’s license and a logbook recording all chemical applications. Be ready to show your customers your spray records Do not store chemicals and farm equipment in the same building during growing season, harvest and drying

Pesticide Analysis (ppm) Common Name Type Class Trade Names Fungicide Quinone Inhibitor Insecticide/Miticide Boscalid MRL Wisc Hop Zampro®, Orvego® 100 0. 70 Pyrethroids Talstar®, Onyx. Pro®, Attain®TR 10 0. 26 Fungicide Pyridine-carboxamide Emerald® 35 0. 23 Cyazofamid Fungicide Cyano-imidazole Segway®O 10 1. 9 Demethomorph Fungicide Cinnamic acid amides Stature®SC 60 0. 53 Insecticide/Miticide 2, 4 Diphenyloxzoline derivative Tetra. San®, Beethoven™TR 7 0. 49 Famoxadone Fungicide Oxazoles Famoxate® 80 3. 7 Spirodiclofen Insecticide/Miticide Tetronic acids Envidor®, Oberon® 30 0. 26 Ametoctradin Bifenthrin Etoxazole

Pesticide Testing Laboratory Pacific Agricultural Laboratory 21830 S. W. Alexander Lane Sherwood, Oregon 97140 -8427 pacaglab. com Extensive pesticide screening available in beer and hops $330 per hop sample. $260 for beer sample Results within 10 days.

Nitrates High Nitrate levels in foods is considered a health hazard EPA standard for drinking water is < 50 ppm as NO₃ There is no standard for beer Hops contain circa 10, 000 ppm NO₃ Dry hopping @ > 1. 5 pounds / bbl can exceed 50 ppm NO₃ in beer • Take care with nitrogen application. It’s worth tracking petiole NO₃ levels in your hops • Nitrogen x 4. 4268 = NO₃ • • •

Testing of Nitrates in Hop Samples Petial or Cones UW Soil & Forage Laboratory, Marshfield, WI https: //uwlab. soils. wisc. edu/ Sampling info: https: //uwlab. webhosting. cals. wisc. edu/wpcontent/uploads/sites/17/2010/11/A 2309. pdf Submission form: https: //uwlab. webhosting. cals. wisc. edu/wpcontent/uploads/sites/17/2019/02/Forage-Information-Sheet-Fillable. pdf $10 per sample

Testing for Nitrates in Beer Bio-Chem Laboratories Grand Rapids, MI https: //bio-chem. com/ Nitrate (as N) measuring anions by Ion Chromatography $20 per sample OMIC Laboratories Portland, OR https: //omicusa. com/ Nitrate via liquid chromatography $120 per sample

Glyphosate Residuals A Public Relations Concern! Testing at Pacific Agricultural Laboratories $260/sample As Reported on Social Media: “Glyphosate Found in 19 of 20 Beers and Wines Tested. Glyphosate is the active ingredient in Monsanto's Roundup Weed Killer that some studies have linked to cancer. It’s also a secret ingredient in nearly 20 popular beers and wines”

THANK YOU!