Daniel Pambianchi TROUBLESHOOTING YOUR WINES MAY 21-22, 2010 OREGON WASHINGTON

Transcription

1 Daniel Pambianchi TROUBLESHOOTING YOUR WINES MAY 21-22, 2010 OREGON WASHINGTON 1

2 Electrical Engineer 20 years in telecom Founder/President of Cadenza Wines Inc. GM of Maleta Winery in Niagara-on-the- Lake, Ontario (Canada) Contributing Author to & Technical Editor of WineMaker magazine since 2000 Author of Techniques in Home Winemaking (Véhicule Press, 2008) & Kit Winemaking (Véhicule Press, 2009) 2

3 Pambianchi, Daniel. TECHNIQUES IN HOME WINEMAKING: The Comprehensive Guide to Making Château-Style Wines. Newly-Revised & Expanded Edition. Montréal: Véhicule Press

4 19 of the most common problems Symptoms Possible causes Corrective actions Preventive measures You are only as good as your ability to fix problems. My Dad, a wise man 4

5 Symptom Possible Causes Corrective Actions, if any Alcoholic a) Fermentation temperature is a) Adjust temperature fermentation too low or too high is stuck or b) Sugar concentration is too b) Conduct a progressive sluggish high fermentation c) Alcohol content is too high c) Re-inoculate with a strong fermenting yeast strain d) Poorly prepared yeast starter e) Lack of oxygen available to d) Re-inoculate with fresh yeast e) Aerate must/wine by stirring or the yeast f) Lack of nutrients g) ph is too low h) Volatile acidity (VA) is too high i) Free SO 2 content is too high j) Elevated amount of LAB present in the grapes or juice k) Elevated amount of mold in the grapes l) Low yeast count racking f) Prepare a fresh inoculum & add yeast nutrients g) Deacidify & re-inoculate with fresh yeast h) Reduce VA & re-inoculate with fresh yeast i) Aerate must/wine by stirring or racking j) Treat must/wine with lysozyme k) Add yeast nutrients & treat with lysozyme l) Re-inoculate with fresh yeast 5

6 Preventive measures o Assess your fermentation conditions and environment Style of wine, temperature, Brix/SG, ph, quality of the fruit, etc. o Make necessary adjustments o Prepare a proper yeast starter with nutrients o Inoculate o Monitor fermentation progress continually 6

7 Symptom Possible Causes Corrective Actions, if any Malolactic fermentation (MLF) is stuck or sluggish a) Fermentation temperature is too low or too high b) Oxygen (air) has inhibited MLB a) Adjust temperature b) Re-inoculate with fresh MLB and protect from air c) SO 2 content is too high d) ph is too low e) Alcohol content is too high f) MLB have insufficient nutrients g) High levels of inhibitory polyphenols h) Lysozyme concentration is too high c) Re-inoculate with fresh MLB that has high tolerance to SO 2 d) Lower TA or increase ph e) Re-inoculate with a strong MLB strain f) Stir the lees or add yeast/mlb nutrients g) Treat with OptiRED and add fresh MLB h) Treat must/wine with bentonite i) Low MLB count i) Re-inoculate with fresh MLB 7

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9 Preventive measures o Assess your fermentation conditions and environment Temperature, free SO 2, ph, alcohol o Make necessary adjustments o Inoculate with a MLB; do not rely on indigenous bacteria o Maintain proper temperature o Do not aerate o Monitor MLF progress closely 9

10 Symptom Possible Causes Corrective Actions, if any Color is too light a) Light whites: Excessive fining and/or filtration b) Light reds: Excessive fining and/or filtration, poor vintage, poor viticultural practices, grape variety, or too short of a maceration. Also due from aging young, richly colored wine with little tannin content. a) & b) Blend with one or more other wines b) Add grape skin powder for reds, or treat pre-fermentation with natural yeast derivative nutrients in conjunction with macerating enzymes. 10

11 Preventive measures o Harvest at optimal phenolic ripeness o Reds: Macerate for maximum color extraction Pre-fermentation & higher fermentation temperature o Use macerating enzymes o Do not over-fine or over-filter o Use color stabilization techniques and/or products 11

12 Symptom Possible Causes Corrective Actions, if any Wine is browning and/or smells like Sherry Oxidation due to defective or poor use of winemaking equipment, excessive exposure to air during processing or storage, or insufficient sulfite. Lightly oxidized: Treat lightly browned whites with casein, PVPP or OptiWHITE; leave reds alone. If no change, try treating with activated carbon. Heavily oxidized: Discard wine 12

13 Preventive measures o Protect wine from air o Top up barrels regularly o Sulfite judiciously based on ph Use Sulfite Calculator at o Do not over-process o Check all equipment, esp. fermentation locks, tank seals, etc. o Do not age wine indefinitely 13

14 Symptom Possible Causes Corrective Actions, if any Wine smells vinegary or of nail polish remover, and/or has formed a white film Wine has been exposed to air causing an interaction with Acetobacter spoilage organisms and/or wine has not been sufficiently sulfited For mild cases, drink wine if tolerable For more serious cases, dump the wine 14

15 Preventive measures o Protect wine from air and fruit flies o Top up barrels regularly o Sulfite judiciously based on ph o Do not add citric acid if wine will go through MLF o Do not over-process o Check all equipment, esp. fermentation locks, tank seals, etc. o Do not age wine indefinitely 15

16 Symptom Possible Causes Corrective Actions, if any Wine smells of sulfur Overuse of sulfite and/or yeast stressed during fermentation Aerate must/wine by stirring/racking, or Treat must/wine with dilute 3% H 2 O 2 solution 16

17 Preventive measures o Easy with the sulfite; maintain a nominal free SO 2 level based on ph o Do not stress yeast; add nutrients and maintain an adequate fermentation environment 17

18 Symptom Possible Causes Corrective Actions, if any Wine smells of rotten eggs or burnt rubber a) Elemental sulfur on grapes b) Excessive use of sulfite c) Wine in contact with sulfur deposits in oak barrels d) Nutrient deficiency e) Extended contact with gross lees f) Extreme fermentation temperatures g) Yeast strain known to produce high levels of H 2 S For mild cases, rack wine and aerate abundantly For more serious cases, do not aerate wine; treat wine with dilute 1% CuSO 4 solution, with Bocksin, or OptiRED for reds. If no change, try treating with activated carbon. 18

19 Preventive measures o Do not over-spray with sulfur o Sulfite judiciously based on ph o Careful not to drip any sulfur when burning sulfur discs/sticks in barrels o Choose a yeast with low H 2 S production o Do not stress yeast; add nutrients and maintain an adequate fermentation environment o Minimize contact with gross lees o Maintain proper temperature 19

20 Symptom Possible Causes Corrective Actions, if any Wine smells yeasty Wine has been in contact for too long with the lees (autolysis) No corrective action. Drink/dump wine. 20

21 Preventive measures o Minimize contact with gross lees o Rack according to schedule 21

22 Symptom Possible Causes Corrective Actions, if any Wine is cloudy a) Incomplete alcoholic fermentation b) Improper racking/clarification c) Wine is not protein stable d) High pectin content e) Excessive aeration in highiron content wine (ferric casse) a) Let fermentation complete b) Let wine settle until clear and rack carefully; fine/filter as required c) Treat with bentonite d) Treat with pectic enzymes e) Fine/filter, and add ascorbic acid 22

23 Preventive measures o Allow AF and MLF to complete o Rack according to schedule o Fine as recommended; follow instructions for clarifying agents o Filter if desired; make sure pads are oriented correctly o Treat high-pectin wines with pectic enzymes o Test for protein/heat stability and treat wine as required 23

24 Symptom Possible Causes Corrective Actions, if any Wine throws tartrate crystal deposits Wine has not been cold stabilized Rack and cold stabilize wine, or Rack wine and add metatartaric acid 24

25 Preventive measures o Test wine for cold stability and cold stabilize if required Cold stabilize if not sure o Stable Wine A + Stable Wine B Stable Wine AB; blend needs to be reassessed and stabilized if required 25

26 Symptom Possible Causes Corrective Actions, if any Wine is fizzy or carbonated a) Residual CO 2 gas still present in wine b) Incomplete alcoholic or malolactic fermentation a) Degas wine by racking, stirring or using a vacuum pump b) Let alcoholic or malolactic fermentation complete 26

27 Preventive measures o Allow AF and MLF to complete o Do not rush your winemaking o Degas wine o Bottle only when ready 27

28 Symptom Possible Causes Corrective Actions, if any Wine is too sweet a) Incomplete alcoholic fermentation b) Wine is not balanced a) Let alcoholic fermentation complete b) Increase TA to achieve balance, or blend with another wine 28

29 Preventive measures o Assess SG and take corrective actions if Brix/SG is too high o Assess TA and take corrective actions if juice is not balanced o Let alcoholic fermentation complete to dryness, then adjust sugar level as desired 29

30 A wine tolerates acidity better when its alcoholic degree is higher; acid, bitter and astringent tastes reinforce each other; the hardest wines are those which are at the same time acid and also rich in tannins; a considerable amount of tannin is more acceptable if acidity is low and alcohol is high. The less tannic a red wine is, the more acidity it can support (necessary for its freshness); the richer a red wine is in tannins (necessary for its development and for its longevity) the lower should be its acidity; a high tannin content allied to a pronounced acidity produces the hardest and most astringent wines. Peynaud, Émile. The Taste of Wine: The Art and Science of Wine Appreciation. Translated by Michael Schuster. London, England: Macdonald & Co. (Publishers) Ltd,

31 Symptom Possible Causes Corrective Actions, if any TA and/or ph is too low or too high Poor vintage, grape variety, soil conditions or vinification techniques Check expiry date of NaOH solution; redo test with fresh solution if required For high TA/low ph or low TA/high ph, adjust TA and/or ph For high TA/high ph, treat with phosphoric acid, or blend wine For low TA/low ph, blend wine 31

32 Preventive measures o Measure TA/pH pre-fermentation and adjust as required; monitor throughout winemaking o Use fresh NaOH solution for titration o Recalibrate ph meter probe o Take measurements at the correct temperature and degas samples 32

33 Symptom Possible Causes Corrective Actions, if any Wine tastes overly bitter a) Extraction of bad tannins from stems and seeds b) Over-extraction of good tannins from maceration or barrel aging a) & b) Fine with egg whites, PVPP or gelatin, or treat with OptiRED c) Wine is not balanced c) Reduce TA 33

34 Preventive measures o Ease up on phenolic extraction (during maceration, fermentation & barrel aging), esp. for varietals known to have high phenol content o Do not crush seeds, and minimize contact o Destem grapes o Taste, taste, taste throughout winemaking and make adjustments as required to maintain balance 34

35 Symptom Possible Causes Corrective Actions, if any Wine is hot and heady High sugar content in must was fermented extensively Blend wine with low-alcohol wine 35

36 Preventive measures o Reduce the PA by dilution with water (not my preference) o Plan to blend with another wine with low PA o Maintain balance in wine o Chaptalize carefully; review calculations twice before adding sugar; add in stages and check additions with hydrometer 36

37 Symptom Possible Causes Corrective Actions, if any Wine has an unpleasant smell of geraniums Due to addition of potassium sorbate to a malolactic fermented wine No corrective action 37

38 Preventive measures o Avoid using potassium sorbate when wine has gone through MLF 38

39 Symptom Possible Causes Corrective Actions, if any Wine smells moldy or musty The result of a chemical reaction between phenolic compounds in oak wood & wines, and mold or chlorine that produces TCA No corrective action 39

40 Preventive measures o Do not use chlorine-based products in the winemaking area 40

41 Symptom Possible Causes Corrective Actions, if any Wine has a strong barnyard smell Brettanomyces yeast infection In wine: Sulfite and stabilize filter In barrel: Discard barrel if odor is strong 41

42 Preventive measures o Discard barrels and other materials (e.g. skids, cardboards, etc.) known to be infected with Brett 42

43 Symptom Possible Causes Corrective Actions, if any Wine has an unpleasant sour-milk taste Lactobacillus or Pediococcus bacterial infection If wine is drinkable, sulfite and stabilize filter; otherwise, dump the wine 43

44 Preventive measures o Always clean and sanitize all equipment before and after use to rid of any latent yeast or bacteria; pay particular attention to barrels and hard-to-clean surfaces in equipment, i.e., nooks & crannies of hoses, pumps, etc. 44

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46 Symptom Possible Causes Corrective Actions, if any Excessive gushing while disgorging traditionalmethod-made sparkling wine a) Poorly riddled wine b) Contaminated dosage c) Big temperature difference between wine & dosage d) Imperfections in glass a) Re-riddle using the traditional method b) Fine filter dosage c) Keep wine & dosage cool & at same temperature d) Disgorge at cold temperature 46

47 Preventive measures o Fine filter the cuvée o Use a good riddling aid o Use the best glass possible o Riddle using the traditional method o Do not disgorge if any yeast particles still on glass wall; put bottles sur pointes after riddling o Disgorge at cool temperature 47

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