#BBC18: This beer doesn't taste right!

Owen Ogletree's Lightening Talk at #BBC18 www.brewtopia.info

Transcript

1. Owen Ogletree owen.ogletree@brewingnews.com • BJCP National Judge • Conducted hundreds of tasting panels • Siebel Sensory Trainings • GABF and GBBF judge • Knoxville Brewing & Distilling Center
2. This beer doesn’t taste right! • Bloggers need to know beer off-flavors • Identification of off-flavor components • Origin of these flavors and aromas
3. Esters • Fruity notes controlled by yeast strains, wort gravity and fermentation temperature • Ale yeasts vs. lager yeasts • High temperatures • Lots of sugars = high wort gravity = more esters
4. Fusel Alcohols • Diesel fuel / rubbing alcohol notes • High fermentation temperatures • High wort gravity • Wild yeasts
5. Diacetyl • Artificial butter or butterscotch aroma and taste. • Some cannot perceive diacetyl at all. • Fermentation by-product. • Also produced by lactic acid bacteria, notably Pediococcus damnosus
6. Diacetyl • Has a flavorless and odorless precursor that converts to diacetyl with heat or dirty lines • Removal: Do a diacetyl rest on live, active yeast
7. Simple Diacetyl Test Place a sample of young beer in two glasses. Cover and put one in a hot water bath for 20 minutes, while keeping the other at room temperature. Cool both samples. 1. Neither beer smells buttery. Good! 2. The heated sample smells buttery, but the cold one does not. Diacetyl precursor present. Needs a diacetyl rest. 3. Both samples smell like butter. Infected beer! Bad! http://www.professorbeer.com/articles/diacetyl.html
8. Acetaldehyde • Green apples or latex paint • Oxidation or bacterial infection • “Green” beer • Can contribute a pleasant “house” quality to some beers, like those from Samuel Smith in the UK.
9. Astringency • Mouth-puckering sensation like chewing on grape skins • Grain tannins • Spices and some high alpha acid hops • Wild yeasts
10. DMS • Dimethyl-sulfide: aroma and taste of cooked corn, celery or cabbage • DMS evaporates during a long, open, rolling boil • Wild yeast or bacteria
11. DMS • Pilsner malt contains as much as eight times the DMS levels of pale malt • Low levels of DMS are appropriate in some Pils-based American light lagers • Some beers have corn as an adjunct
12. Skunky Beer • Hop exposure to UV light • Mercaptans found in the scent glands of skunks • Green or clear glass bottles • Heineken is NOT supposed to taste like this!
13. Paper/Cardboard/Oxidation • Age / presence of oxygen in the package • Reduced by minimizing splashing of hot wort or of the fermented beer while packaging
14. Lactic Acid • Common souring agent • Clean, sharp sourness – Berliner Weisse • Lactobacillus bacteria also create yogurt • Pediococcus bacteria can produce lactic acid and diacetyl
15. Breweries Need a Microscope
16. Sherry-Like • Aroma and taste of dry sherry, hazelnut or almond • Oxidized malt melanoidins • Can add complexity to aged strong ales
17. Sulfury/Yeasty • Aroma and taste of rotten eggs, shrimp or rubber • Possible sources: yeast autolysis, bacterial spoilage and water contamination
18. Phenols • Phenolic = aroma and taste of band-aids or disinfectant • Chlorophenols have bleach-like flavors • Bacteria or wild yeast • Phenols may also be extracted from grain husks by over-crushing, over-sparging or sparging with hot or alkaline water
19. Phenols • Chlorinated water and sanitizer residue are possible sources of chlorophenols • Phenolic flavors are generally bad, except for the pleasant, clove, vanilla, or slightly smoky notes of Bavarian wheat beers and some Belgian ales
20. Want to talk more? Owen Ogletree www.Brewtopia.info owen.ogletree@brewingnews.com