Identifying Wine Faults or What I DON’T want to smell in my wine By Lisa Jones lisa.jones@vincor.ca

Overview Sensory detection of Wine Faults Most Common Wine Faults Sulphurous Compounds Lactic Acid Bacteria Brettanomyces Yeast Autolysis & Wild Yeasts Oxidation Environmental

salty, sweet, sour, bitter or umami 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.

Sensory Evaluation #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.

“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.

“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.

Sulfur

Sulfurous Compounds Sulphur Dioxide - SO2 Hydrogen Sulfide - H2S 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) Cruciferous vegetable (cabbage, brocolli, cauliflower, asparagus) And vegetables from the Genus Allium (onion, garlic)

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!

Lactic Acid

Lactic Acid aka. Lactobacillus MLF What is it? Used in commerical wines to create buttery esters and flavour components. Great, but uncontrolled bacteria can cause wine to go off. Malic Acid – used in super sour candies, Mega warheads Lactic Acid – Milk acid, milkder buttery esters

MLF Faults MLF in the bottle Geranium Taint Graisse 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

Brettanomyces

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” -when at low levels it contributes to the complexity of the wine and can give an “aged” character to some young reds. Past the “sensory threshold” it is seen as a fault -It metabolizes the disaccharide cellulose in oak and makes wine barrels an ideal carrier of this wild yeast -controlled by sulfur dioxide

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

Candida

Pichia

Yeast Wild Yeast (Candida, Pichia) Yeast Autolysis 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

Oxidized

Oxidation The 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

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

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

CLEANLINESS IS NEXT TO GODLINESS. Oxidation, cont. Ethyl Acetate Symptoms: nail polish, glue, varnish, fake fruit Causes: spoilage causing bacteria Acetyl Aldehyde Symptoms: sherry, green apple, sour, metallic Actetic Acid Symptoms: vinegar CLEANLINESS IS NEXT TO GODLINESS.

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.

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 natural process that occurs over time when the salts of tartaric acid and potassium salt form. Prevention: Cold stabilization or addition of metatartaric acid to temporarily keep crystals in suspension.

So one last time… PLEASE.. Clean and Sanitize Questions??