O P T IM IZ IN G H O P QUA LITY Zac German Technical Manager z ac.german@ychhops.com
Outline 1. Quality Factors Varietal Purity Growing Practices Approaches to handling variability 2. Growing for Oil vs Alpha Bitterness vs. Aroma Alpha and Oil development Determining Harvest Timing Analytical vs. Sensory Early vs. Late Harvest 3. Post Harvest Hop Quality Hop Storage Index (HSI) Moisture and Kilning Hop quality and storability
Quality Factors Regional/Abiotic latitude, climate, soil structure Root Stock Age, Health and Purity Cultural Practices Burnback, training, vines/acre, cover cropping Harvest Timing Harvest Handling Pickers, kilns, farm cold storage, processors, cold storage 3
Considerable alpha and oil variability in Cascade 2.0 1.9 1.8 Low AA High Oil Alpha vs Oil CASCADE High AA High Oil State OR WA HSI 0.20900 0.22000 0.24000 0.26000 0.30200 1.7 1.6 Oil 1.5 1.4 Average 1.3 1.2 1.1 1.0 Low AA Low Oil 5.8 6.0 6.2 6.4 6.6 6.8 7.0 7.2 7.4 7.6 7.8 8.0 8.2 8.4 8.6 8.8 9.0 9.2 Alpha Average High AA Low Oil 4
Varietal Purity Clonal propagation from a single parent for multiple generations Accumulates disease over time Susceptible to competition from off-types (other varieties) Presence of males 5
Visual assessment of consistency and outliers Outliers can be brought to grower attention to identify potential cause
Propagation Establishment Other factors: Yard age, virus free, males, pest pressure 7
Cover Crops Moonscapes Cultural Practices Other factors: Salmon Safe, Global GAP, Organic, IPM, Fertility 8
Cascade Simcoe YCR 14 cv. ~2.5% Alpha ~2.5% Alpha ~7% alpha range
What s a Supplier to Do? A. Collaboratively develop Best Farming practices to improve crop consistency B. Embrace Variation and work with growers and brewers to make the most of it. C. Blend lots for consistency of the varietal 10
Considerable alpha and oil variability in Cascade 2.0 1.9 1.8 Low AA High Oil Alpha vs Oil CASCADE High AA High Oil State OR WA HSI 0.20900 0.22000 0.24000 0.26000 0.30200 1.7 Oil 1.6 1.5 1.4 1.3 1.2 Average Do you embrace the variability or try to homogenize the crop? 1.1 1.0 Low AA Low Oil 5.8 6.0 6.2 6.4 6.6 6.8 7.0 7.2 7.4 7.6 7.8 8.0 8.2 8.4 8.6 8.8 9.0 9.2 Alpha Average High AA Low Oil 11
Growing for Alpha vs Oil (Bittering) (Aroma) Bittering Hops boiled for a long time to stabilize bitterness. Typically, most aroma character is lost when hops are used for bittering. Brewers have many choices for adding bitterness. Super-alpha varieties: CTZ, Apollo, Bravo, Warrior, etc. Advanced products: CO 2 extract, Isomerized extracts, etc. Aroma Boiled for short time or not at all. Delicate aroma compounds are retained, some bitterness is produced at high hopping rates. Majority of hops in craft breweries are used for aroma. Highlights uniqueness of hop, making the beer unique!
Growing for Alpha vs Oil (Centennial)
Growing for Alpha vs Oil (Cascade) Alp 9.0 8.5 8.0 7.5 7.0 6.5 6.0 2.2 458 456 178 66 460 157 466 315 408 467 162 461 469 174 317 409 Alpha vs. Harvest Date 319 412 320 411 214 447 464 218 164 328 327 Aug 19 Aug 24 Aug 29 Sep 3 Sep 8 Sep 13 Sep 18 Sep 23 Harvest Date [2013] 413 220 415 Oil vs. Harvest Date 227 334 417 229 330 418 231 114 114 392 393 CASCADE HSI 0.2000 0.2200 0.2400 0.2600 0.3000 Grower ID G024 G032 G037 G057 G064 G078 G079 G088 G094 G096 G137 2.0 461 326 248 1.8 462 229 246 392 Oil 1.6 162 320 464 328 413 415 227 418 245 1.4 1.2 458 456 460 178 66 466 213 412 411 214 218 327 228 417 330 231 393 1.0 157 408 164 Aug 19 Aug 24 Aug 29 Sep 3 Sep 8 Sep 13 Sep 18 Sep 23 Harvest Date [2013] 14
Growing for Alpha vs Oil (Citra )
Determining Harvest Timing Harvest too Early Low Alpha Low Oil Reduced yield next year Harvest too Late Poor aroma (onion, garlic) Oxidation Disease & Pests
Determining Harvest Timing Dry Matter Easy to test at home Classic method Hop cones dry naturally as they mature Mature cones have ~22-23% dry matter (77-78% moisture) Alpha vs Oil development requires lab equipment Harvest when target alpha is reached What if target is never reached? Harvest when oil stops increasing What if oil doesn t stop increasing? Know your crop, use your senses Onion / Garlic Pests Browning cones Grassy / Vegetal / Green aroma Dankness! http://www.uvm.edu/extension/cropsoil/wp-content/uploads/hop_harvest_fact_sheet.pdf
Factors that affect post-harvest hop quality Light Never good, but especially bad if the cones and glands are broken, easy to control Heat Accelerates chemical breakdown (oil and alpha) Hops at 75 degrade 4x faster than frozen Oxygen Loss of bitterness Cheesy aroma Moisture
Metrics of hop quality Dankness Onion / Garlic / Cheese Alpha, Oil Hop Storage Index (HSI) Alpha Acid potential lost in 6 months, at 68, in bales Initial: 10% AA, 0.250 HSI (25%) After 6 months at 68 : 7.5% AA (25% less than Initial) It s really not this easy After 6 months at 28 : 9.0% AA (10% less than Initial)
Hop Storage Index (HSI) Hop compounds absorb specific wavelengths of light. Oxidation compounds absorb light near 275 nm, Alpha Acids absorb near 325 nm*. OOOOOOOOO CCCCCCCCC AAAAA AAAAA = AAAAAAAAAAAAAA AAAAAAAAAAAAAA As hops age, alpha decreases, oxidation products increase, and HSI goes up. HSI is an indicator of hop degradation, but DOES NOT enable calculation of future alpha loss (e.g. after 6 months ) * Note that this is an oversimplification
Hops should be dried to 8.5-10.5% moisture Ideally, pick cones and begin drying within hours of cutting bines. Under-dried hops oxidize, turn brown, smell musty (rotten lettuce) Over-dried hops shatter, lose aroma
Hops should be dried to 8.5-10.5% moisture Pitfalls when drying Outer bracts dry quickly. Inner strig retains moisture longer. Hops feel dry, but moisture remains inside. Moisture equalizes in bag, causing hops to feel soggy.
Simple method for drying samples of hops Standard household food dehydrator Insert thermometer in top vents Target 135 F (57 C) Maximum airflow 3-4 hours on our dehydrator Drying and measuring moisture: http://msue.anr.msu.edu/news/drying_hops_on_a_small_scale http://www.uvm.edu/extension/agriculture/engineering/?page=hopscalc.html
Degradation of Tomahawk baled hops 18.0 0.800 16.0 0.700 14.0 0.600 % Alpha Acid 12.0 10.0 8.0 6.0 0.249 0.297 0.285 0.410 0.369 0.518 0.500 0.400 0.300 HSI 4.0 0.200 2.0 0.100 0.0 0 2 6 Months After Harvest 0.000
Alpha loss is greater with high harvest HSI % Alpha Loss 0.50% 0.45% 0.40% 0.35% 0.30% 0.25% 0.20% 0.15% 0.10% 0.05% 0.00% Alpha Loss Per Day in Storage (baled hops) HSI <0.275 HSI >0.275
Alpha loss is greater with high harvest HSI HSI < 0.230
Alpha loss is greater with high harvest HSI HSI < 0.230 HSI 0.230
High harvest HSI loses more alpha per day
HSI generally does not increase through the normal harvest window
Two exceptions in our data
Conclusions Alpha is generally stable within the harvest window Oil generally increases throughout harvest Brewers generally shopping for aroma hops Trend would suggest harvesting as late as possible to maximize oil / aroma. Post-harvest processing critical to preserving alpha, oil, and aroma Consequences of later harvest Unwanted aromas Potentially higher HSI Loss of storability If hops won t be in long-term storage, brewers likely to prefer later harvest hops.
Thank you! Ashley Trenkenschuh Brad Titus Amanda Smalling Alex Jensen Joe Catron Zach Turner Missy Raver Steve Carpenter