Clarifica(on and Colloidal Stabiliza(on of Cask Ales. Ian L Ward Brewers Supply Group Nov 2011

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1 Clarifica(on and Colloidal Stabiliza(on of Cask Ales Ian L Ward Brewers Supply Group Nov 2011

2 Cask Ale Naturally Carbonated Cellar Temperature Subtle, Nuanced Aroma and Flavor Cloudy?

3 Cask Ale should be clear! Cask Ale should be clear bright and appealing Cask Ales served in England oden rejected if not sparkling bright With agen(on to process and detail cask ales can be bright as well as delicious!

4 What causes beer haze? BIOLOGICAL PARTICLES Brewers Yeast Wild Yeast Bacteria NON BIOLOGICAL PARTICLES (NMP) Particulate matter Protein Polyphenol complex Carbohydrate e.g. Starch Calcium oxalate Lipids Brewers Yeast Wild Yeast Bacteria CLARIFICATION & PACKAGING Calcium oxalate Protein Polyphenol complex Carbohydrate Addition Related

5 Brewing Process Turbidity Input Dust from malt handling Husk material Protein Polyphenols Hop Particles Trub Yeast Precipitation of cold break Precipitation of protein polyphenol complexes Malt Mash tun Lauter tun Wort kettle Whirlpool Fermenter Storage / maturation Filtration Control Measure Pneumatic or mechanical grain cleaning Filtration of wort through husk Coagulation of protein poly phenol to give trub Separation of trub & Hops Settlement of cold break Application of Yeast Flocculent Final Filtration PACKAGING

6 Control of haze inputs Since no final filtra(on haze inputs must be controlled at every opportunity Biological inputs controlled by good hygiene Wild yeast and bacteria very difficult to fine by standard fining techniques Good brew house and cellar hygiene a given Casks to be properly cleaned & inspected.

7 Selec(on of Raw Materials Malt quality is the first step in controlling the protein load presented the the clarifica(on system Ideally malt should be < 10% protein UK brewers seek less than 9.5% Since Cask Ales are oden low in alcohol flavorsome varie(es such as Maris OGer or Golden Promise find favor Malt should be well modified

8 Milling & Mashing Proper control of mill se]ngs to control husk and ensure a proper mash tun / lauter bed Cask Ale can be made using isothermal mash tuns, lauter tun or mash filter systems provided that system gives good wort clarity Avoid flooded bed or channeling, excessive raking, or over extrac(on

9 Changes in Total Polyphenol Levels During the Brewing Process Polyphenol Concentration mg/l Mash In First Runnings Last Runnings Kettle Up Kettle Cast Brewing Process Whirlpool Fermentation Maturation

10 Proline Residue and Polyphenol Interac(on Polyphenol- Protein Complex Polyphenol monomer Proline residue HA protein

11 Control of Wort Proteins Good vigorous boil Although important for a host of reasons Hop isomeriza(on Flavor development DMS reduc(on Steriliza(on etc Protein coagula(on during boil is cri(cal to reduce to par(culate load in green beer.

12 In Cask ale no filtra(on Brewer cannot rely on a final filtra(on to correct deficiencies Clarity is achieved by gravity! v = 2(ρ p - ρ f )r 2 g 9η V = velocity of settlement ρ p = density of the particles ρ f = density of the fluid r = radius of the particle g = acceleration due to gravity η = viscosity of the fluid

13 Brewing Process Turbidity Input Dust from malt handling Husk material Protein Polyphenols Hop Particles Trub Yeast Precipitation of cold break Precipitation of protein polyphenol complexes Malt Mash tun Lauter tun Wort kettle Whirlpool Fermenter Storage / maturation Control Measure Pneumatic or mechanical grain cleaning Filtration of wort through husk Coagulation of protein poly phenol to give trub Separation of trub & hops Settlement of cold break Application of Yeast Flocculent Cask Racking

14 Control of Wort Proteins KeGle Finings Tradi(onally Irish Moss ~ Chondrus crispus Raw seaweed added to the kegle to provide protein coagula(on Ac(ve ingredient K- carrageenan Modern materials derived from Euchema cogonii

15 Ac(on of KeGle Finings K- carrageenan is a nega(vely charged carbohydrate polymer that binds to posi(vely charged wort proteins Op(mally kegle fined worts present beer fining systems a manageable par(culate load Several product formats available from powders granules to tablets Typically added minutes to end of kegle boil

16 Kettle Fining and Protein Levels Control 10ppm 20ppm 30ppm 40ppm 50ppm

17 Fermenta(on & Condi(oning ph drops reducing solubility of proteins Protein- polyphenols react to form large insoluble proteins Yeast flocculates at end of fermenta(on Ensure selec(on of good floccula(ve yeast Ensure good cold condi(oning

18 Brewing Process Turbidity Input Dust from malt handling Husk material Protein Polyphenols Hop Particles Trub Yeast Precipitation of cold break Precipitation of protein polyphenol complexes Malt Mash tun Lauter tun Wort kettle Whirlpool Fermenter Storage / maturation Control Measure Pneumatic or mechanical grain cleaning Filtration of wort through husk Coagulation of protein poly phenol to give trub Separation of trub & hops Settlement of cold break Application of Yeast Flocculent Cask Racking

19 Tradi(onal Finings ~ Isinglass

20 Isinglass Mechanism of Interaction 1. Negatively charged yeast cells and neutral NMPs. 2. Positively charged isinglass interacts with negatively charged yeast cells to form flocs 3. Flocs settle rapidly as described by Stokes Law, entrapping NMP s

21 Isinglass Mechanism of Interaction 1. In practice as well as yeast cells, dead cells and protein are present as uncharged or +ve species 2. Auxiliary finings are strongly ve polymers which adhere to the +ve protein and dead cells rendering everything in suspension -ve 3. Isinglass reaction is now possible by adsorption 4. Complete clarification is observed fit for cask beer

22 Electron Micrograph of Isinglass & Yeast

23 Rules for Isinglass Use Once in liquid for keep cold! <10degC Use liquid isinglass within 3 weeks Isinglass must be well mixed into the beer Make sure the beer is cold when fining Solubility of beer proteins propor(onal to temperature Isinglass only removes insoluble material Allow beer to warm to serving temperature Any residual protein is likely to dissolve rather than precipitate

24 Applica(on of Finings Auxiliary finings added to the cask or matura(on tank prior to beer (typically 0.25 pt per firkin) Beer filled into cask Isinglass solu(on (0.3% w/v, typically 1 pint per firkin) Isinglass not mixed with Auxiliary Finings Bung hammered in

25 Alterna(ves to Isinglass Isinglass non- vegetarian Although overblown, concern over fish allergies Bovine collagen heavily researched but even less desirable than isinglass Colloidal Silica holding promise Combined fining and stabiliza(on Does not readily resegle mul(ple (mes

26 Effect of Dry Hopping Wonderful for aroma! Terrible for clarity! Extra polyphenol loading interacts with beer proteins to yield a haze Hop Aroma products Use of silica / isinglass

27 New Development Fastcask Beer segled at the brewery Yeast immobilized onto gel beads are added to the cask like finings Yeast provides for carbona(on as normal Due to size and density gel beads segle very quickly Cask Ale can be served bright immediately Beer can be resegled mul(ple (mes