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Identifying Wine Faults

orWhat I DON’T want to smell in my

wineBy Lisa Jones

lisa.jones@vincor.ca

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Overview

• Sensory detection of Wine Faults• Most Common Wine Faults

• Sulphurous Compounds• Lactic Acid Bacteria• Brettanomyces • Yeast Autolysis & Wild Yeasts• Oxidation• Environmental

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Sensory Evaluation#1 Smell• 80-90% of perceived taste is actually

smell. The tongue only tells us:salty, sweet, sour, bitter or umami

Try this out –close your eyes, take a candy, plug your nose and taste. Try and guess what it is.

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#2 Appearance-Watch your wine – there are some very obvious problems, but what may seem like a wine that’s not clearing - turbidity or cloudiness could also be an indication of infection.

Sensory Evaluation

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“Why does my wine smell like bacon?”• It cannot be stressed enough –

Good cleaning and sanitation will prevent most of the wine problems.

• Basics – Cleaning (Saniton, Sanibrew, Microzyme, PBW)

– Cleaning- To remove visible and/or invisible grime, soil, grease, fats,etc. from surfaces that come in contact with wine.

• Basics – Sanitation (Potassium Metabisulfate, Iodofor, Sanibrew)

– Required step that ensures product contact surfaces are free from microbial growth, eliminates potential spoilage organisms. Not a substitute for cleaning or poor cleaning – you can’t sanitize a dirty surface.

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“Why does my wine smell like bacon?”• Inspect Fermenters, hoses, bottle fillers for

cracks, chips, excessive staining, etc. Don’t be hesitant to retire equipment.

• Be cautious of any used equipment.• Consider all contact points and times - filter

plates, bottle filler nozzle, overflow tub, etc.• Insist on clean bottles – when a consumer

has some good and some bad bottles – contamination occurred during bottling or is from the bottles.

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Sulfur

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Sulfurous Compounds• Sulphur Dioxide - SO2

– Symptoms: Matchsticks or burnt rubber– Cause: Over-sulphiting grapes, must or wine– Resolution: Keep good records – don’t over sulfite

• Hydrogen Sulfide - H2S – Symptoms: Rotten eggs– Cause: Stressed yeast/struggling fermentation– Prevention: Ensure must has enough nutrients

and is in acceptable temperature range (most yeast 65-80°F/18-25°C)

– Resloution: Aerate wine when smell is first noticed – splash rack. H2S can be removed with Bocksin or Copper (Copper Sulfate or other)

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Sulfurous Compounds, cont.• Mercaptans

– Symptoms: Onion, garlic or skunk– Cause: Hydrogen Sulfide left untreated– Treatment: Ascorbic acid, Deodorizing

Carbon filtration, etc.• Dimethyl Sulfide

– Symptoms: Cooked cabbage– Cause: Oxidized Mercaptans

JUST AVOID THIS!

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Lactic Acid

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Lactic Acid aka. LactobacillusMLF What is it?

Used in commerical wines to create buttery esters and flavour components. Great, but uncontrolled bacteria can cause wine to go off.

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MLF Faults• MLF in the bottle

– Symptoms: Spritz, turbidity, musty, stale dishcloth– Prevention: Add sulfides to avoid unintentional MLF

• Geranium Taint– Symptoms: Smell of rotten geranium leaves– Cause: Lactic Acid Bacteria and Potassium Sorbate– Prevention: Do not treat wine that have undergone MLF

with Potassium Sorbate. Don’t do MLF to kit wines.

• Graisse– Symptoms: “Ropiness”, slimy or fatty mouth feel, egg

white – Cause: Lactic Acid infection creating dextrins and

polysaccharides– Prevention: Use only commercial sources of lactobacillius

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Brettanomyces

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Brett – friend or foe?

• Cause: one of nine wild yeasts present in every wine region in the world

• Symptoms: Barnyard, antiseptic, bacon, sweaty saddle, wet dog, mousy, metallic as well as sediment and carbonation– At lower levels is complexity and not a

“fault”

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Prevention of Brettanomyces

• Cleanliness • Know your barrels – sometimes the

best use is as a planter

• Proper levels of SO2 in wine

• Keep wines topped up• Cross contamination – Brett spreads

easily

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Candida

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Pichia

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Yeast• Wild Yeast (Candida, Pichia)

– Symptoms: Sherry-like, oxidized flavours, film on wine – called “flor” yeast or “flowers of yeast”

– Prevention: Always inoculate with a wine yeast or culture – do not leave it to chance. Minimize ullage - top up wines, spray surface with SO2

• Yeast Autolysis– Symptom: yeasty, brothy, meaty, rubbery, fatty– Causes: wine left on lees and cells to break down,

done intentionally to create depth of flavour in some wines - “champenoise” method of making sparkling wine.

– Prevention: Get wine off lees after fermentation is complete

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Oxidized

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OxidationThe most common wine faults as the presence

of oxygen and a catalyst are the only requirements for the process to occur. Oxidation can occur throughout the winemaking process, and even after the wine has been bottled.

• Processing Oxidation– Symptoms: raisin, caramel, nutty, cough syrup,

orang-ish brown colour of reds, dark golden white wines

– Causes: wine left in primary too long, carboy left not topped up, wine not sulfited

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Cork Taint• Cork taint is a wine fault mostly

attributed to the compound 2,4,6-trichloroanisole (TCA) As cork taint has gained a wide reputation as a wine fault, other faults are often falsely identified as it. – Symptoms: earthy, mouldy, and musty

aromas in wine that easily mask the natural fruit aromas

– Causes: TCA most originates as a metabolite of mould growth on chlorine-bleached wine corks and barrels

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Storage Problems• “Cooked Wine”/Maderized

Wines exposed to extreme temperatures will thermally expand, and may even push up between the cork and bottle and leak from the top. Even if the temperatures do not reach extremes, temperature variation alone can also damage bottled wine through oxidation.– Symptoms: corks pushing out of bottles, rim of red wine

around cork, prune, stewed flavours, oxidized compounds– Causes: overly hot storage area

• Light Struck Wines– Symptoms: cardboard or wet-wool flavour– Causes: wine exposed to ultra-violet light

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Oxidation, cont.• Ethyl Acetate

– Symptoms: nail polish, glue, varnish, fake fruit– Causes: spoilage causing bacteria

• Acetyl Aldehyde– Symptoms: sherry, green apple, sour, metallic– Causes: spoilage causing bacteria

• Actetic Acid– Symptoms: vinegar– Causes: spoilage causing bacteria

CLEANLINESS IS NEXT TO GODLINESS.

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Sediment• Re-fermentation

– Symptoms: carbonated or “spritzy” wine, sediment, dry when it should be sweet.

– Causes: Not adding (or not adding enough) Potassium Sorbate to a wine that has had sugar or sweetener added, incomplete alcoholic fermentation.

– Prevention: If adding less than 1 ¼ cup wine conditioner add 2 teaspoons potassium sorbate.

– NOTE: some believe it adds a “bubblegum” flavour to wine if too high a dosage is added.

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Sediment, continued• Tartrate Crystals (aka wine diamonds)

– Symptoms: clear or sometimes bown, crystaline deposits on bottom of the bottle or on cork, may be mistake for glass. More likely to occur with wine stored in cold location.

– Causes: Tartaric acid crystallization is a naturalprocess that occurs over time when the salts of tartaric acid and potassium salt form.

– Prevention: Cold stabilization or additionof metatartaric acid to temporarily keepcrystals in suspension.

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So one last time…

• PLEASE..

Clean and Sanitize

• Questions??