February 29 2020 The Art of Hop Selection One Brewers Opinion The Life Of A Hop Bale QUALITY HARVEST DRYING STORAGE PELLETING STORAGE BREWING What is HSI Developed in the early 1970s by two USDA Scientists Tax Dollars ID: 931254
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Slide1
Daniel Carey
New Glarus Brewing CompanyFebruary 29, 2020
The
Art of Hop Selection – One Brewer’s Opinion
Slide2The Life Of A Hop Bale
QUALITY
HARVEST
DRYING
STORAGE
PELLETING
STORAGE
BREWING
Slide3What 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 325nm 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 @ 275nm
Acids Absorbance @ 325nm
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
.”
Slide4What 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
Slide5A 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
Slide6When to Harvest?
Correct Harvest Date
Based on past history. Climate variability!Moisture, of courseHSI 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 AromaBrowning of cones. Less “curb appeal”More impactful aroma that is preferred by some brewersKnow your varieties and you customers!
Higher HSI at Harvest leads to greater degradation in storage
Slide7An 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 are 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 same 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
Slide8Hop 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.
Slide9Ambient Drying
Your secret weapon! A quality and marketing advantageYou can do it because you have time. You are not “Dryer Constrained” like your competition
A Gentle process with Minimal impact on HSIBigger “window” to reach proper moistureMore even treatment across bed. < 1% moisture delta!Less cone shatter. No need to disturb bed!
Preservation of Aroma and Bitterness
Slide10Hop Bale Material of Choice?
Plastic
Cardboard
Burlap
Polypropylene
Slide11Bale Compression
US Norm 155 – 160 kg/m3
5 – 10% crushed LupulinGerman Norm for RB60 bales100 – 150 kg/m32 – 3% crushed Lupulin
Slide12Bale 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
Slide13Relative 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
Slide14Who 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?
Slide15What 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
Slide16Slide17Slide18Slide19Pelletizing 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
Slide20Pelletizing 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
Slide21Other Considerations
PesticidesNitrates
Glyphosates
Slide22Pesticides
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
Slide23Pesticide Analysis
(
ppm
)
Common Name
Type
Class
Trade Names
MRL
Wisc Hop
Ametoctradin
Fungicide
Quinone Inhibitor
Zampro®, Orvego®
100
0.70
Bifenthrin
Insecticide/Miticide
Pyrethroids
Talstar®, OnyxPro®, Attain®TR
10
0.26
Boscalid
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
Etoxazole
Insecticide/Miticide
2,4 Diphenyloxzoline derivative
TetraSan®, Beethoven™TR
7
0.49
Famoxadone
Fungicide
Oxazoles
Famoxate®
80
3.7
Spirodiclofen
Insecticide/Miticide
Tetronic acids
Envidor®, Oberon®
30
0.26
Slide24Pesticide Testing Laboratory
Pacific Agricultural Laboratory
21830 S.W. Alexander LaneSherwood, Oregon 97140-8427pacaglab.com
Extensive pesticide screening available in beer and hops
$330 per hop sample. $260 for beer sample
Results within 10 days.
Slide25Nitrates
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
Slide26Testing of Nitrates in
Hop Samples
P
etial or Cones
UW Soil & Forage Laboratory
,
Marshfield, WI
https://uwlab.soils.wisc.edu/
Sampling info:
https://uwlab.webhosting.cals.wisc.edu/wp-content/uploads/sites/17/2010/11/A2309.pdf
Submission
form:
https://uwlab.webhosting.cals.wisc.edu/wp-content/uploads/sites/17/2019/02/Forage-Information-Sheet-Fillable.pdf
$10 per sample
Slide27Testing 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
Slide28Glyphosate 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”
Slide29THANK YOU!