1. 123rd MBAA Anniversary Convention Fresh Beer, Fresh Ideas MBAA – New England January 2014 Alastair Pringle Pringle –Scott LLC

2. Objective and Outline Objective – Identify practical solutions for keeping beer as fresh as possible. Outline – Background – What is freshness? – Reactions in brewhouse, fermentation, & finishing – Practical steps to freshness improvement – Making decisions on freshness 2

3. Background - Factors that Affect Beer Shelf Life Microbiological spoilage – Bacteria: lactic acid, diacetyl, H 2 S, etc – Yeast: over-attenuation, over carbonation – Physical stability – Chill-haze – Permanent haze Flavor stability – Changes in flavor 3 This talk will focus on flavor stability

4. Background - Why Worry About Flavor Stability? Customers want a consistent flavor They accept consistent flavor, even if it includes off-flavors – e.g. DMS, oxidation, light-struck They reject variable flavors – Beer will not meet their expectations – Do not like surprises 4

5. Freshness in the Marketplace Wide freshness variation – confuses the customer Narrow range – customer gets a consistent product 5 Frequency Stale Fresh Frequency Stale Fresh

6. WHAT IS FRESHNESS? 6

7. Freshness Freshness is how close a product is to when it was : – Picked from the field – Made in the bakery or brewery Implied: – Better taste – Better nutrition – No artificial preservatives 7

8. Changes in Beer Freshness begins to decline once beer is packaged The decline is accelerated by increased temperature 8 80 o F 70 o F 36 o F Less Fresh

9. Why Does Beer Lose Freshness? 9 Sulfite Cardboard Paper Ester Bitter Harsh Sweet Staling is the sum of many flavor changes: - no single compound or mechanism is responsible - there is no single solution Intensity Time

10. Where Should You focus? Across the entire system 10 BreweryWholesalerRetailer BrewhouseFermentation Finishing Packaging We will first look at the brewing process

11. BREWHOUSE 11

12. First, a Word about Carbonyls A class of compounds that contain a C=O group C=O Include: – long-chain unsaturated aldehydes. 1969 - trans-2-nonenal was shown to impart a stale, cardboard, flavor when added to beer. – other volatile carbonyls: ketones, esters 12 A B

13. Brewhouse Chemistry - Mashing and Lautering - 13 Unsat. Fatty Acids Carbonyls Lipase Polyphenols Tannins O2O2 Lipoxygenase Malt polyphenolsMalt LipidsMalt Protein Amino Acids Protease Oxygen is important in carbonyl production

14. Brewhouse Chemistry - Boiling - 14 Polyphenols Carbonyls O2O2 Iso-alpha acids Extraction Isomerization Tannins + Protein Carbonyl-protein Wort protein From Mashing Maillard Products Unsat. Fatty Acids Heat Amino acidsHopsSugar Copper Vessels & coils Oxygen and heat drive complex reactions Malt Tannins

15. FERMENTATION 15

16. Fermentation Chemistry 16 Carbonyls Alcohols Protein– carbonyl SO 2 SO 2 – carbonyl Sulfate H+H+ Yeast Ethanol Sugars SO 2 SO 2 is an important anti-oxidant, especially in lagers Carbonyls become bound to protein and SO 2 Iron Yeast Iron Uptake Autolysis

17. FINISHING AND PACKAGING 17

18. Finishing and Packaging Chemistry 18 Iron Reactive Oxygen Species O 2 - superoxide anion HOO - perhydroxyl radical H 2 O 2 hydrogen peroxide HO. hydroxyl radical OxygenFilter medium

19. Chemistry in the Package - reactions involving oxygen- Oxygen Reactive Oxygen Species Finished Beer Package Iron & Copper Sulfur Dioxide Iso-alpha acids Sulfate Sweet, fruity e.g. Ethyl isovalerate Side chain Polyphenols Harsh, astringent tannins + Others reactions – oxidation of ethanol and higher alcohols Ethanol Diagram courtesy of Grace Darex Packaging Technologies ingress D.O.

20. Chemistry in the Package -reactions independent of oxygen- 20 SO 2 – carbonyl Protein – carbonyl Carbonyl + Maillard Products + Paper, cardboard e.g. Trans-2-nonenal Solvent e.g. furfuryl ethyl ether SO 2 Other reactions – esterification, etherification, glycoside hydrolysis, & ester hydrolysis Ethanol These compounds, which developed in the brewhouse, result in stale flavors in the package

21. The Brewing Process - factors that are important for freshness - Yeast – SO 2 21 BrewhouseFermentation Finishing Packaging Oxygen Metal ions Oxygen Heat Oxygen

22. PRACTICAL STEPS TO FRESHNESS IMPROVEMENT 22

23. How can Freshness be improved? Maximal freshness can only be achieved by making improvements across the entire production chain – Chain is as good as its weakest link – Do not only focus on one area 23 BreweryWholesalerRetailer

24. Brewhouse Freshness Best Practices Mashing 24 Bottom entry Fore masher Course grind Malt No scorching or build-up No votex upon emptying Water Effective mixing that minimizes foam and creates no vortex Pump seals maintained to avoid air pick-up Minimize exposure to air

25. Brewhouse Freshness Best Practices - Lautering - 25 Bottom mash entry Side mash entry Minimal Foam Not exposing the grain bed or Minimize exposure to air

26. Brewhouse Freshness Best Practices – Boiling - 26 Gentle fill minimizing foam Avoid extended boil time Efficient heat transfer – minimal scorching No vortex during emptying Pump seals maintained to avoid air pick-up Avoid boil temperatures above 212 F Minimize air and heat Vigorous boil

27. Brewhouse Freshness Best Practices - Whirlpool- 27 Tangential flow Minimal foam on wort surface Pump seals maintained to avoid air pick-up Gentle wort flow Avoid excess time Minimize air and heat exposure

28. Fermentation Best Practices Increase SO 2 levels in lagers – SO 2 is an antioxidant – below level requiring labeling Minimize yeast autolysis – Can release iron into beer. 28 Fermentor Yeast Maturation Increase SO 2 Reduce autolysis Lower ferm. tempX Lower aeration rateX Lower pitch rateX Increase yeast foodXX Lower maturation temp.X Reduce maturation timeX

29. Finishing Best Practices 29 De-oxygenate adjustment water Filter Beer Tank Water Filter Gas with CO 2 before filling Use low iron D.E. Chiller Buffer Chill- proofer Maintain to avoid oxygen pick up Seals maintained to avoid air pick-up De-oxygenate water Minimize air and iron pickup

30. PACKAGING 30

31. Packaging Freshness Best Practices Minimize oxygen – Finished beer D.O. should be low (50 ppb or less) – Bottles Evacuation CO 2 flushing Proper adjustment of jetters – Cans Use CO 2 flushing Bubble breakers Under-cover gassing with CO 2 31

32. Measuring Package Oxygen Shake-out method – fair – Better than not measuring oxygen – Detects very high levels – Too inaccurate to be used for driving down oxygen levels Dissolved oxygen – better – Pierce package and run beer through a DO meter. – Detects beer DO levels - but not headspace oxygen Total package oxygen - best – Oxygen in beer + headspace oxygen – Semi-automatic 32

33. Packaging Materials Best Practices Many more times the oxygen may enter the package over its shelf-life as is present immediately after packaging 33 Package TypeSource of oxygen ingressImprove freshness through: Glass Bottle Crown Barrier crown - better Absorbing crown – best Plastic Bottle Closure Bottle Barrier crown – better Absorbing crown – best Oxygen barrier – nylon Absorbing technology – e.g. Co Can Minimal ingress Diagram courtesy of Grace Darex Packaging Technologies

34. DISTRIBUTION 34

35. Distribution Chain Control - It all about Time and Temperature - Higher temperature leads to a rapid loss of freshness – 2 to 4 times more for every 18 o F (10 o C) – Beer stored at 80 o F for 50 days will be as fresh as beer stored at 70 o F for 100 days Draft beer that is kept cold will remain fresher than packaged 35 40 o F 80 o F 70 o F Keeping beer cool and for shorter times means beer is consumed fresher – local production and distribution helps Less Fresh

36. MAKING FRESHNESS DECISIONS 36 Photo courtesy of PureMalt

37. Tools to Assess the Process Process assessment – Visual: Vortexing Excessive foam in brewery vessels Scorching on heat exchange surfaces – Measurement Excessive levels of dissolved oxygen where you have clear liquid – Lauter – Wort receiver – Kettle knock out 37

38. Freshness Measurement Focus on a reliable measure related to the consumer experience. – Sensory is the best measure – Avoid complex chemical analyses – Measurement of radicals is mainly related to SO 2 and or iron level Develop a Freshness Panel – Train using in-house or outside expertise (FlavorActiv) – Develop a scale: e.g. 1 to 10 Use the panel to provide feedback on experiments and process improvement efforts – Does a process change improve freshness? – Is the cost worth it? – What is the shelf-life of a beer? 38

39. Beer Shelf-Life Determination 39 70 F 32 F Less Fresh Shelf-life is the time before the beer tastes unacceptably different from fresh beer X

40. Summary Freshness of beer in the marketplace is affected by: – Production methods from the brewhouse to the finished package – Storage conditions after the beer is packaged The freshness of beer that reaches the consumer can be enhanced by systematically improving each link in the chain as much as practically possible 40 BreweryWholesalerRetailer

41. The Art of Beer 41 Pringle-Scott.com Questions?