Fresh Beer, Fresh Ideas MBAA – New England January 2014

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

3. Background - Factors that Affect Beer Shelf Life • Microbiological spoilage • Bacteria: lactic acid, diacetyl, H2S, etc • Yeast: over-attenuation, over carbonation • Physical stability • Chill-haze • Permanent haze • Flavor stability • Changes in flavor 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

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

6. What is Freshness?

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

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

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

10. Where Should You focus? • Across the entire system Brewery Wholesaler Retailer Brewhouse Fermentation Finishing Packaging We will first look at the brewing process

11. Brewhouse

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 A B

13. Brewhouse Chemistry - Mashing and Lautering - Malt Protein Malt Lipids Malt polyphenols Lipase Unsat. Fatty Acids Polyphenols Protease O2 Lipoxygenase Amino Acids Carbonyls Tannins Oxygen is important in carbonyl production

14. Brewhouse Chemistry- Boiling - Unsat. Fatty Acids Hops Sugar Amino acids Polyphenols Extraction From Mashing O2 Heat Malt Tannins Carbonyls Isomerization Vessels & coils Wort protein Tannins + Protein Carbonyl-protein Iso-alpha acids Maillard Products Copper Oxygen and heat drive complex reactions

15. Fermentation

16. Fermentation Chemistry Sulfate Sugars Iron Carbonyls Uptake Yeast Yeast Autolysis SO2 H+ Protein– carbonyl SO2– carbonyl Alcohols SO2 Ethanol Iron SO2 is an important anti-oxidant, especially in lagers Carbonyls become bound to protein and SO2

17. Finishing and Packaging

18. Finishing and Packaging Chemistry Filter medium Oxygen Iron Reactive Oxygen Species O2- superoxide anion HOO- perhydroxyl radical H2O2 hydrogen peroxide HO. hydroxyl radical

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

20. Chemistry in the Package-reactions independent of oxygen- SO2– carbonyl Carbonyl + SO2 • Paper, cardboard • e.g. Trans-2-nonenal Protein – carbonyl + Ethanol • Solvent • e.g. furfuryl ethyl ether Maillard Products Other reactions – esterification, etherification, glycoside hydrolysis, & ester hydrolysis 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 • SO2 Brewhouse Fermentation Finishing Packaging • Oxygen • Heat • Oxygen • Metal ions • Oxygen

22. Practical steps to freshness Improvement

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 Brewery Wholesaler Retailer

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

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

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

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

28. Fermentation Best Practices • Increase SO2 levels in lagers • SO2 is an antioxidant • below level requiring labeling • Minimize yeast autolysis • Can release iron into beer. Maturation Fermentor Yeast

29. Finishing Best Practices De-oxygenate adjustment water Use low iron D.E. Water Buffer Gas with CO2 before filling Filter Beer Tank Filter Chill- proofer De-oxygenate water Chiller Seals maintained to avoid air pick-up Maintain to avoid oxygen pick up Minimize air and iron pickup

30. Packaging

31. Packaging Freshness Best Practices • Minimize oxygen • Finished beer D.O. should be low (50 ppb or less) • Bottles • Evacuation • CO2 flushing • Proper adjustment of jetters • Cans • Use CO2 flushing • Bubble breakers • Under-cover gassing with CO2

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

33. Packaging Materials Best Practices • Many more times the oxygen may enter the package over its shelf-life as is present immediately after packaging Diagram courtesy of Grace Darex Packaging Technologies

34. Distribution

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 18oF (10oC) • Beer stored at 80o F for 50 days will be as fresh as beer stored at 70oF for 100 days • Draft beer that is kept cold will remain fresher than packaged Less Fresh 40oF 70oF 80oF Keeping beer cool and for shorter times means beer is consumed fresher – local production and distribution helps

36. Making Freshness Decisions 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

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 SO2 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?

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

40. Summary Brewery Wholesaler Retailer • 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

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