Off Flavor Flash

A

Buttery Minnesota Home Brewers Association: Sean P. Hewitt

1/26/06

Cardboard Minnesota Home Brewers Association: Sean P. Hewitt

1/26/06

Troubleshooting Off-flavors- Buttery Describe/Discuss

Ever Appropriate?

If so, what styles?

How is it caused?

How can it avoided/ controlled?

- Butterscotch

Yes

Scotch Ales Bitters Dry Stouts Czech Pils Oktoberfest

Diacetyl: - Premature racking

- Allow ferment to complete

- Diacetyl - Aroma - Mouthfeel, a slickness on the palate

- Low fermentation temperature

- Higher temperature primary fermentation - Good pure yeast strain

- Mutant yeast - Lactic acid bacteria (Pediococcus)

- Practice good sanitation - Quick wort chilling

- Long periods of wort cooling

Troubleshooting Off-flavors- Cardboard Describe/Discuss

Ever Appropriate?

If so, what styles?

How is it caused?

How can it avoided/ controlled?

- Papery

No

N/A

- Aeration of hot wort

- Quiet transfer of beer when siphoning or transferring

- Wet cardboard - Rotten fruit

- Aeration of beer during bottling

- Stale

- excessive age

- Serve beer in appropriate amount of time

- Sherry-like

- High storage temperatures

-Cool (<55F) storage temps

- Adding tap water to finished without boiling

-Add only boiled water

- in Aroma and Flavor

A

Cloudiness Minnesota Home Brewers Association: Sean P. Hewitt

1/26/06

Cooked Corn Minnesota Home Brewers Association: Sean P. Hewitt

1/26/06

Troubleshooting Off-flavors- Cloudiness Describe/Discuss

Ever Appropriate?

If so, what styles?

How is it caused?

How can it avoided/ controlled?

- Cloudy

Yes

Wheat Beers Lambics American Wheat

Chill haze: - Insufficent conversion time

- Longer mash

Permanent Haze: - High sparge temps

- Use finings

Bacterical Haze: - Poor sanitation

- Reduce sparge temps

Powdery Yeast

- Practice good sanitation

- in Appearance

- Use protein rest

- Use filtration

- Use well-flocculating yeast strain

Troubleshooting Off-flavors- Cooked Corn Describe/Discuss

Ever Appropriate?

If so, what styles?

How is it caused?

How can it avoided/ controlled?

- DMS (dimethyl sulfide)

Yes

American Lagers Cream Ales

- Covered boil

- Open, rolling boil for an hour

- Vegetal (Sweet cooked corn, celery, cabbage, parsnips) - Shellfish or oyster-like in higher amount - in Aroma and Flavor - Precursor S-methylmethionine (SMM) occurs naturally in Pale malt, turns into DMS with heat, evaporates

- not boiling wort for at least an hour - Wild yeast or Zymomonas bacteria (converted from Dimethyl sulfoxide) - High level of adjuncts - Overnight cooling

- Poor sanitation - Reduce corn or rice in mash - Quick wort cooling

A

Fruitiness Minnesota Home Brewers Association: Sean P. Hewitt

1/26/06

Light Body Minnesota Home Brewers Association: Sean P. Hewitt

1/26/06

Troubleshooting Off-flavors- Fruitiness Describe/Discuss

Ever Appropriate?

If so, what styles?

How is it caused?

How can it avoided/ controlled?

- Esters

Yes

Ales

- Alcohols combining with acids at higher temperature. (Ethyl acetate, Isoamyl acetate, Ethyl Hexanoate)

- lower fermentation temperature

- in Aroma and Flavor

American Dark Lagers (very light)

- Strawberries

Dopplebock (in dark versions)

- Choose a different yeast

- Raspberries Eisbock - Pear - Plums - Grapefruit - Banana - Apricots. etc

Troubleshooting Off-flavors- Light Body Describe/Discuss

Ever Appropriate?

If so, what styles?

How is it caused?

How can it avoided/ controlled?

- Watery

Yes

American Light lagers

- Lack of dextrins

- Use quality malt

- Poor quality malt

- Keep percentage of sugars small

- Large percentage of sugar

- Reduce length of protein rest

- Weak Lambics - in Flavor and Mouthfeel -

- Over-long protein rest - High mash temperature

- Lower mash temperature - Use dextrin or wheat malt. Flaked malt

A

Low Head Retention Minnesota Home Brewers Association: Sean P. Hewitt

1/26/06

Phenolic Minnesota Home Brewers Association: Sean P. Hewitt

1/26/06

Troubleshooting Off-flavors- Low Head Retention Describe/Discuss

Ever Appropriate?

If so, what styles?

How is it caused?

How can it avoided/ controlled?

- Flat

Yes

Lambics

- Insufficient proteins in beer causes high surface tension

- Shorten protein rest

- Dirty/oily glasses

- Use flaked wheat or barley

- Low protein grist

- Lower alcohol by lowering the grist bill

- in Appearance and Mouthfeel

High Alcohol Beers

- Use clean wellrinsed glasses

- use hops with high alpha acids

Troubleshooting Off-flavors- Phenolic Describe/Discuss

Ever Appropriate?

If so, what styles?

How is it caused?

How can it avoided/ controlled?

- Band-aid

Yes

Some Belgians beers

- Wild yeast

- Use pure yeast strains

- Medicinal Smoke beers

- Improper sanitation

- Clove-like Some Wheat beer - Plastic - Smoky - in Aroma and Flavor

- Some malt types - Some yeast strains - Chlorophenols in water - Improper rinse of chlorine sanitizers

- Practice good sanitation - Use “clean” malt - Use yeast less prone to phenolic production - filter tap water - Use non- chlorine sanitizers

A

Sherry-like Minnesota Home Brewers Association: Sean P. Hewitt

1/26/06

Sourness Minnesota Home Brewers Association: Sean P. Hewitt

1/26/06

Troubleshooting Off-flavors- Sherry-like Describe/Discuss

Ever Appropriate?

If so, what styles?

How is it caused?

How can it avoided/ controlled?

- Sherry

Yes

Barleywines

- Oxidative yeasts acting on higher alcohol beers creates aldehydes (ie. trans-2-nonenal)

- Use different yeast strain

- Vinous

English Old Ales

- Wine-like

- Create less alcohol by lowering grist bill

- Paper-like

- Serve beer younger

- Old

- Ferment cooler

Troubleshooting Off-flavors- Sourness Describe/Discuss

Ever Appropriate?

If so, what styles?

How is it caused?

How can it avoided/ controlled?

- Tart

Yes

Witbier Lambics Flanders Ale Berliner Weisse

- Lactic acid (from lactic acid bacteria)

- Practice good sanitation

- Sour - in Aroma, Flavor and Mouthfeel -perceived on sides on the tongue

(optional sourness) American Wheat or Rye, Dry Stout, Witbier and Saison

- Acetobacter (from acetic acid) - excessive acid rest - mashing too long

- Don’t employ overlengthy mash or low temp mash

A

Acetaldehyde Minnesota Home Brewers Association: Sean P. Hewitt

1/26/06

Alcoholic Minnesota Home Brewers Association: Sean P. Hewitt

1/26/06

Troubleshooting Off-flavors- Acetaldehyde Describe/Discuss

Ever Appropriate?

If so, what styles?

How is it caused?

How can it avoided/ controlled?

- Green apples

Yes, at low levels

L/S/P American Lagers (from yeast character is optional)

- Premature removal from yeast

- Allow ferment to complete

- Grassy - can taste and smell acetic/ cidery

- Bacterial spoilage

- Practice good sanitation and beer handling to avoid O2 contact

- Oxidation - Good yeast strain - Premature flocculation -Oxygen depletion

- Aerate wort prepitching - long lagering will reduce

Troubleshooting Off-flavors- Alcoholic Describe/Discuss

Ever Appropriate?

If so, what styles?

How is it caused?

How can it avoided/ controlled?

- Hot, Spicy

Yes

Stronger ales and lagers

- High amount of fermentables

- Pitch sufficient yeast quantity

- Underpitching

- Aerate wort prepitching

- Vinous aroma - Prickly mouthfeel - warmth

- Low O2 or FAN

A

Astringent Minnesota Home Brewers Association: Sean P. Hewitt

1/26/06

Bitterness Minnesota Home Brewers Association: Sean P. Hewitt

1/26/06

Troubleshooting Off-flavors- Astringent Describe/Discuss

Ever Appropriate?

If so, what styles?

How is it caused?

How can it avoided/ controlled?

- Dry, Mouth puckering

No

N/A

- Extraction of tannins (overcrushing, oversparging)

- Don’t overcrush

- Alkaline water

- Use acidified water in sparge

- in Flavor and Mouthfeel - like grape skins

- Lengthy Hop immersion times - Polyphenols from acetobacter

- Keep sparge temp low

- Reduce hop immersion times - Practice good sanitation

- Oxidation - Spices

- Reduce spice additions

Troubleshooting Off-flavors- Bitterness Describe/Discuss

Ever Appropriate?

If so, what styles?

How is it caused?

How can it avoided/ controlled?

- Mouth puckering

Yes

IPA’s

- High AAU hops

- Use hops with lower alpha acids

Pales ales

- Lengthy hops times

- Bitter English Bitters - Flavor - Mouthfeel

-

- Reduce hop boil times