Dry Hopping Georg Drexler Technical Manager, Joh. Barth & Sohn Blumenau, 08. Juli 2016
Agenda Calculations Aspects of Dry Hopping Recent Studies 2
Calculations for Aroma dosages Various calculation possibilities for dosages into the Whirlpool (= late hopping) or during fermentation / maturation / storage of the beer (= dry hopping): According to g of hops (experience?) - dosage 20 to 1000+ gr/hl According to Linalool content According to hop oil content According to alpha acid content - dosage 10 to 500+ µg/l - dosage 0.2 to 10+ ml/hl - not the best alternative (Dry hopping calculations are the same/similar to late hopping)
Choosing an Aroma Dosage Benchmark Year 1 Year 2 Year 1/Year2 Alpha-acids % by wt 3 5 Hopoils ml/100 g 0,5 0,65 Linalool mg/100g 4 5 Amount Amount of hops g 100 100 1 Alpha-acids g/hl 3 5 0,6 Hopoils ml/hl 0,5 0,65 0,77 Linalool mg/hl 4 5 0,8 Alpha content Amount of hops g 100 60 0,6 Alpha-acids g/hl 3 3 1 Hopoils ml/hl 0,5 0,39 0,78 Linalool mg/hl 4 3 0,75 Oil content Amount of hops g 100 77 0,77 Alpha-acids g/hl 3 3,85 0,78 Hopoils ml/hl 0,5 0,5 1 Linalool mg/hl 4 3,85 1,04 4
Consistent hop aroma is not a guarantee There are several possibilities for hop addition calculations There is no 100 percent guarantee to get the same hop aroma in beer every time: Deviation in aroma of raw hops from year to year (crop to crop) Different hop growing regions and even hop gardens show different aroma of raw hops Even if the amount of dosed hop oils is the same: the composition of the hop oil might be different There are interactions between hop oils and other beer compounds which may lead to variations of the aroma in the final beer Changes in the brewing process can cause influences on the hop aroma in beer 5
Agenda Calculations Aspects of Dry Hopping Recent Studies 6
Dry Hopping Technique (probably) originating from Great Britain Gaining popularity because of the US craft beer movement Extraction in a solution with a relatively low alcohol content Added to the cold-side (cellar) Many different methods 7
Why dry hopping? Hop serves as the main flavour ingredient Special aroma profile Raw hop character Single hopped beers Beer style (e.g. IPA, Pale Ale, Lagers, etc.) Marketing strategy Dry hopping is a huge playground for beer innovations 8
Dry hopping can... Improve/intensify bitterness due to aroma interaction Increase the polyphenol content Influence the colloidal stability Improve the flavour stability Enhance foam stability Change the flavour after filling Increase/change drinkability 9
Parameters Hop variety Hop product Quantity Time Temperature Beer composition Yeast Dynamic or static Place and method of addition/separation 10
Hop variety and hop products All hop varieties and types can be used Variety, time of harvest and origin ( Terroir ) have an impact Hop Cones Less contact area lower yield Possible milling before addition Addition/removal depends on method Pellets are most commonly used Pre-milled increases contact area Easy to dose Hard to remove Hop oils/emulsions Water soluble hop oil fractions (PHA Topnotes) 11
Point and method of addition Primary fermentation Lower yields Sedimentation with yeast = less contact time and no yeast harvesting Lagering/maturation/bright tank Most breweries dry hop at this point Packaging Keg Bottle Directly before serving At the tap Dynamic or static 12
Multiple Breweries Recirculation Tank This is the simplest and probably the most frequently used method among breweries that dry hop. Hop pellets are added to a vessel that is purged with carbon dioxide. Beer is circulated through the vessel for a certain amount of time. 13
Sierra Nevada Brewing Co. Torpedo This dry hopping equipment was specifically made by Sierra Nevada to maximize their whole hop. The torpedo itself is a vessel where the whole hops are added. After hops are added, the vessel is purged with carbon dioxide. The top and bottom of the vessel are connected with hoses allowing the beer to recirculate. 14
Hop Cannon Known to be created by Lagunitas Brewing Company, this system is composed of a vessel that will deliver hops to a fermentation tank. This vessel is filled with hop pellets and pressurized with carbon dioxide. The pressure differential between the hop cannon (higher) and fermentation tank (lower) delivers a blast of hops into the vessel. The hops are then dispersed into the fermentation tank. 15
ROLEC DryHOPNICK System This equipment is based on the same principle with an addition of a shearing mill (3). Hops are added to the dosing vessel (1), the vessel is put under pressure and the hop/beer mixture is circulated. 16
HopGun (BrauKon) This equipment provides dry hopping for the small brewer. There is a see-through vessel where whole hops, pellet hops or even freshly picked (green) hops can be added. The sieves inside the HopGun keep much of the hop material in the vessel and the vessel is purged with carbon dioxide. The beer is then circulated until the desired hop impact is achieved. 17
Hop separation Too many particles before filtration pre-filtration?! If available separator/centrifuge Aroma losses due to filtration No filtration sedimentation during lagering, sediment in the bottle 18
Factors influencing the hop aroma variety time of harvest crop year, kilning Point of addition solubility/ evaporation adsorption/ transformation/ interactions dry hopping (with/out yeast) duration, temp, agitation etc, aroma in hops to hoppy aroma in beer Harvest Brewhouse Fermentation Lagering plus..filtration.bottling storage
Agenda Calculations Aspects of Dry Hopping Recent Studies 20
Hop Aroma >> 400 hop aroma compounds For 150 years researcher try to unlock the mystery of hop aroma in beer Only one characteristic impact compound that is responsible for a typical hop aroma (linalool) does not exist The complex interaction of hop and beer aroma compounds determines the aroma and flavour and is unique for every beer Different thresholds Synergistic effects hop aroma interactions Biotransformations during the brewing process 21
Hop oil components 440 compounds identified, 1000 + are likely! Substance Group (Hopfen- vom Anbau bis zum Einsatz in Bier, Hans Carl Verlag) Concentration Monoterpenes (myrcene, pinene etc.) approx. 40 % Sesquiterpenes (ß-caryophyllene, α-humulene) approx. 40 % Carboxylicacid-esters (methyl-esters) approx. 15 % Carboxylicacids approx. 1 % Monoterpenoxides (linalool, geraniol etc.) approx. 1 % Sesquiterpenoxides (humullenol II, humulen epoxides) approx. 1 % Aldehydes, Ketones (hexenal, epoxydecenal, undecanone, octadienone) approx.1 % Aliphatic hydrocarbons < 1 % Sulfur containing compounds (4-MMP, 3-M-4-MP) < 0,1 % Glycosidically bound aroma compounds?
Sensory relevant Hop Aroma Compounds in Beer Sensory description Substance Conc. In beer Threshold in beer Black currant 4 MMP 0,1 ppb 0,0002 ppb Apple, peach, fruity Beta-damascenone 10-80 ppb 0,02 ppb Rhurbarb, grapefruit 3-M-4-M-P 0,07 ppb Floral, citrussy, lavender Linalool 10-200 ppb 2-80 ppb Floral, rose Geraniol 5-100 ppb 4-300 ppb Citrussy, lime, Lychee Beta-Citronellol 5-50 ppb 9-40 ppb Estery, apple ethyl 2-methyl-butanoate 1-10 ppb 1-45 ppb Fruity, estery ethyl 4-methyl-pentanoate 1-3 ppb 1-18 ppb Resionous, herbal Myrcene 0-500 ppb 9-1000ppb Green, metallic (z)-1,5-octadien-3-on n. d. 0,0034 ppb Hoppy, pineapple (e,z)1,3,5-undecatriene n. d. no data Cedarwood Caryophylla-3,8-dien-(13)-dien-5beta-ol n. d. no data Cheesy/onion/garlic Various sulfur compounds 1-10 ppb 1-500 ppb http://methods.asbcnet.org/hop_flavors_database.aspx 23
Fruity thiols Many thiols have extremely low thresholds and are very active (>5 ng/l) E. g. 4-MMP, Cassis, black currant --- cat urine Also responsible for rhubarb, grapefruit, grape, muscat, white wine flavours (Sauvignon Blanc) Can be experienced negatively according to concentration, configuration and individual perception. unpleasant pleasant onion, burnt, rubber, cat urine grapefruit, rhubarb, currant, muscat 24
What is the role of the yeast? King, 2000, Yeast 2000; 16: p.499±506. 25
What is the role of the yeast? Glycosidically bound aroma components: Daenen 2008: pronounced exo-ß-glucanase activity in Saccharomyces brewing yeasts leads to a higher release of certain aglycones. Brettanomyces brewing yeasts hydrolyses glycosidically bound volatiles of hops. Ting 2009: named 28 hydrolysis products by ß-glucosidase from glycosides 26 Kollmansberger, 2006
Time for extraction Myrcene and Humulene Wolfe, Shellhammer 2011 27
Time for extraction Linalool and Geraniol Wolfe, Shellhammer 2011 28
Interaction of Hop Aroma Compounds 1+1 2 29
Concentration Synergistic effects Synergestic effects Beer 1 Beer 2 Beer 3 No perceivable flavour perceivable flavour Threshold concentration Substance A Substance B 30
Hanke et al. 2009 31
Thresholds of bitter compounds 32 Hofmann, 2011
Thresholds of bitter compounds Orange: German Pilsner Green: IPA (dry hopped) Hofmann, 2011 33
Summary: Dry Hopping Dry hopping is an effective tool for flavour differentiation It has to be part of an elaborate hopping regime A dry hop aroma can not be explained with the current knowledge on hop aroma, myrcene is definitely important New studies indicate that the extraction process is more rapid than thought Difference between dry hopping with cones vs. pellets Individual solutions according to brewery set up Temperature and adsorption are the enemies Dynamic flavour changes after bottling Effective suppression of stale aldehydes The best way to showcase a hop variety 34
How much hops do I need for 100 l Beer? Sometimes people ask us: How much hops do I need for 100 liter Beer? There is no easy answer: depending on the brewing process, the hop products used, as well as bitterness and hop aroma in beer, there are huge differences! International, light hopped Lager Beer: 7 BU, only slightly hoppy Dosage of pre-isomerized downstream products Usage of high alpha varieties, e. g. 15% alpha acid content Less than 7 g Hops are necessary for 1 hl Beer! (Ø-Price: 6 Ct. per hl!) US Craft Beer, e. g. (Double/Triple) IPA: 50 100 BU, extreme hop aroma Only raw hops or hop pellets are used Dosage of aroma varieties (only a small percentage of bitter varieties, if any) 500-1000 g Hops and even more per 1 hl Beer! (Ø-Price: 8 per hl and even more!) The average price for a hop dosage could be around 10-30 Ct / hl Beer. 35
Thank you for your attention! georg.drexler@johbarth.de www.hopsacademy.com www.barthhaasgroup.com 36