Todd Steiner Enology Program Manager & Outreach Specialist Department of Horticulture & Crop Science The Ohio State University/OARDC Wooster, OH 44691 THANK YOU! 2014 Northeast Ohio Winter Grape School Ashtabula County Extension Office David Marrison NE Ohio Winter Grape School Sponsors OSU Extension AARS KSU/Vesta Host: The Lodge at Geneva on the Lake 1
Outline Demystifying Wine Tasting A brief overview of sensory evaluation Addressing wine quality through the recognition of wine flaws Wine flaws initiating from the vineyard Sensory Evaluation Important for the commercial wine industry from harvest to bottling Evaluation of juice samples for maturity and off aromas Evaluating the fermentation process Post fermentation during Wine aging Fining trials Blending trials Post bottle storage and aging quality 2
Senses Used in Wine Tasting Sight: Used in determining a wines appearance of color and clarity Smell: Used in identifying wine aroma and bouquet (very complex) Taste: Used in determining sweetness, sourness, bitterness and saltiness in addition to helping perceive balance (sugar/acid ratio) Touch: temperature, pain, tactile sensations of astringency (tannin), viscosity (sugar & alcohol) Senses Used in Wine tasting Of the senses used in tasting wine, smell is arguably the most important attribute (near 70 percent) Retro nasally Wine warms up in the mouth and releases further aromatic compounds/molecules which reach the olfactory region by diffusion and through exhalation Specialists express flavor as utilizing the sense of smell and taste of wine component s together 3
Sense of Aroma Sense of Taste Sweet taste is provided by alcohol and sugars Sour taste comes from free organic acids Bitter comes from wine phenolics (mainly tannin) Salty not as pronounced in sensory evaluation of wines but can be present (Cations: K, Na, Ca, Mg and Anions: phospate, sulfate, tartrate, malate and lactate along with excess fermentation nutrients 4
Senses Used in Wine tasting Many wines exhibit an interrelation of the senses when performing sensory evaluation of wine descriptors A cloudy wine will most likely have a less pleasant, less distinctive or off aroma An recent vintage white wine with brown hues may have an oxidized aroma A wine with distinct varietal aroma is less likely to express taste deficiencies on the palate Performing Sensory Evaluation When performing sensory evaluation, evaluate the following sensory descriptors often utilized in most national and international wine competitions: Appearance: Color and Clarity Color: Should be representative of variety, vintage, style and blend composition Clarity: Should be free of any amorphous haze or deposit and brilliant in color 5
Performing Sensory Evaluation Aroma and Bouquet: The aroma is derived from the grape itself (varietal character) The bouquet is derived from the cellar through fermentation, processing, or aging The winemaker s desire should be to perfect an unmistakable characteristic aroma of the grape variety or wine type in addition to an outstanding and complex bouquet Performing Sensory Evaluation Taste: Flavors should carry nicely from the aroma onto the palate The wine should be balanced in regards to the fruit present, sugar/acid ratio, tannin, alcohol and other processing attributes such as oak and lees perception These all add up to form the body/mouthfeel of the wine The key to a balanced wine is that one of these attributes should not mask another excessively 6
Performing Sensory Evaluation Aftertaste: All of the aromas, flavors and tactile sensations of the wine should be balanced in a way to provide a pleasing, lingering aftertaste or finish Overall Impression: Taking all sensory descriptors being evaluated in mind, what is the overall impression of the wine being evaluated 7
Sensory Evaluation In light of this, it is vital to become familiar with varietal characteristics, wine styles and wine flaws This can be accomplished through increased tasting of all wines on a personal basis Taste, Taste, Taste Avoid varietal racism Avoid cellar palate Participate in educational tastings including wine flaw recognition Kits are also available in both varietal characteristics and wine flaws Sensory Evaluation It is advisable to become familiar with sensory descriptors to help aid the process The Wine Aroma Wheel provides an excellent tool for this process Develop standards for training winery personnel on these descriptors Nobel, A. C., R. A. Arnold, J. Buechsenstein, E.J. Leach, J. O. Schmidt, and P.M. Stern, Modification of a Standardized System of Wine Aroma Terminology. Am. J. Enol. Vitc. 38: 143 146 (1987) When working with wine flaws, it is important to use a control base wine when comparing the flaw in the same wine matrix 8
Sensory Evaluation According to Paynaud (1996) the role of tasting expertise is not the identification of anonymous wines, but the exercise of quality control. Its function is to judge whether a wine is free of fault which might lessen its value or render it unfit for consumption and to see whether it has qualities required by its denomination. Source: Peynaud, E. 1996. The Taste of Wine. The Art and Science of Wine Appreciation. Wiley & Sons, New York. 9
Wouldn t It Be Great! Wine # 1 White Wine Control: 2011 Pinot Gris 10
Wine # 2? Acetic Acid Spoilage (VA) Aroma: A wine measuring high in VA will give off a sharp, pungent vinegar aroma Lesser concentrations below 0.70% can lead to increased complexity depending on variety Cause: Acetobacter and Gluconobacter All belong to the family Acetobacteriaceae 11
Acetic Acid Spoilage (VA) Cause: Aerobic bacteria metabolism oxidizing ethanol and glucose producing acetic acid Small amounts of ethyl acetate will contribute to a vinegary taint Acetic Acid Spoilage (VA) Two ways of introduction into must and wine Grapes damaged or rotten fruit Dirty cellar equipment such as pumps, hoses, tanks and contaminated wooden barrels Provides an indicator of cellar hygiene 12
Acetic Acid Spoilage (VA) Factors favoring acetic acid production Optimal temperatures vary from 10 C (50 F) to 35 C (95 F) Appearance of acetic acid bacteria may form a film, haze or pellicle located mainly on the surface Acetic Acid Spoilage (VA) Factors favoring acetic acid production High ph in must or wine Aeration of wine during transfer Headspace levels in tanks and barrels Warm storage temperatures Low sulfur dioxide 13
Acetic Acid Spoilage (VA) Prevention of acetic acid spoilage Starts in the vineyard with clean fruit avoid rot, high ph or high soluble solids Grapes containing significant amounts of rot should be treated with 50 75 ppm SO 2 Acetic Acid Spoilage (VA) Prevention of acetic acid spoilage Ferment with a commercial recommended strain for the variety you are vinifying Avoid natural fermentations Punch the cap down a minimum of twice daily for red wine fermentations Helps prevent fruit fly inoculation 14
Acetic Acid Spoilage (VA) Prevention of acetic acid spoilage Once fermentations are complete the proper amount of SO 2 should be added to the wine Monitor and maintain SO 2 levels based on ph to.8 ppm molecular to bottling Keep tanks and barrels topped off Develop a sound sanitation practice Acetic Acid Spoilage (VA) Remedy: reduction is difficult however, there are several possible solutions Reverse osmosis coupled with ion exchange Oxidative yeast fining utilizing acetic acid as a carbon source Blending may be an option for wines lower in volatile acidity 15
Acetic Acid Spoilage (VA) Tasting Room Information If suspected, pull from shelf and notify winery owner/winemaker immediately VA flaws are most likely whole tank or bottling related Concentration of VA typically higher in late harvest and dessert wines TTB legal level not to exceed 0.12% in white wine and 0.14% in red wine Wine # 3? 16
Multicolored Asian Lady Beetle (MALB) Cause: (MALB) were introduced in the late 1970 s and early 1980 s as a biological control agent for aphids and other soft bodied insects Since the emergence of the Chinese soybean aphid the (MALB) population exploded in early 2,000 s mainly in Ohio, New York, Pennsylvania and Canada MALB Cause: Approximately 13 years ago (2001) MALB became a problem with many homeowners as a nuisance pest and in some Ohio Vineyards and Wineries. There increased presence and numbers during this time caused a drastic sensory defect in wine. 17
MALB Cause: This beetle produces a defense chemical when agitated or stressed The beetles enter the winery during grape harvesting in harvest containers, lugs or bins The infested grapes are crushed, destemed and pressed into the juice to be fermented into wine MALB Cause: It appears predominately in late ripening varieties such as Vidal, Vignoles, Riesling, Gewurztraminer, Catawba, Cabernet Franc and Cabernet Sauvignon Pinot Gris may be an exception due to soft tissues and the tendency for rot exposing the sugars 18
MALB Juice and Wine Aroma Exhibits a musty, dirty, damp basement odor masking varietal character and fruit expression Also described as rancid peanut butter, asparagus and bell pepper according to studies published by Brock University Pickering et. al. Am. J. Enol. Vitic. 55:2 (2004) MALB Difficult to predict occurrence of (MALB) 2001 was a bad year with high presence 2002 exhibited virtually no presence in Ohio 2003 showed significant presence in localized regions of the state 2005 observed some MALB taint throughout state Since 2005 MALB observed as being low and sporadic due to lower concentrations of soybean aphid 19
MALB A significant effort at OSU/OARDC involved collaboration of the Department of Entomology and the Enology program in identifying aroma threshold concentrations and effective spray programs for this problem MALB Sensory research by OARDC Enology program indicates detectable threshold levels of this chemical in wine vary greatly between individuals Observed significant detectable sensory threshold in consumer panel of 1.25 beetles per liter correlating to approximately 24 beetles per harvest lug 20
MALB OARDC research on Aza Direct used on Vidal Blanc in 2007 as a chemical deterrent and its effect on wine quality Indicated no significant difference between the control and sprayed treatments in wine Represents good news since it has a O day to harvest Dr. Roger Williams indicated Aza Direct as being fairly efficient as a chemical deterrent for MALB MALB Possible Remedy Control of MALB through chemical sprays, deterrents, or pheromones Mechanization in shaking the grapes on the vine before harvesting or in the winery Air blast fans blowing beetles out of canopy prior to harvest Questionable procedure due to blowing clusters off vine and embedded beetles in cluster 21
MALB Possible Remedy There is still no full proof remedy in solving this problem in wine Developing a soaking tank to float beetles on surface and removing them Not recommended for dilution of certain hybrid and vinifera varieties Preliminary research at Cornell University might suggest that Teflon may help remove this compound in juice and wine (Not TTB Approved) MALB Possible Remedy Research at Brock University reported fining agents such as activated carbon, oak chips and bentonite may work with limited success The above treatments would definitely be variety and wine style dependent Blending with a fruity aromatic wine such as Traminette, Muscat, Vidal or Riesling may help mask this defect 22
MALB Tasting Room Information Sensory evaluation can vary in regards to human threshold concentrations Can be very detrimental to aroma and taste attributes Represents whole tank or barrel lots If suspected, pull bottle from shelf and present to tasting room manager, owner or winemaker May help in developing preventative measures for next harvest Wine # 4? 23
Hydrogen Sulfide Aroma: Higher levels resemble rotten eggs while lower levels impart a yeasty aroma Also express aromas of sulfur, flatulence and loss of fruit Cause: Yeast metabolic activity of organic, inorganic and elemental sulfur can lead to the production of hydrogen sulfide Hydrogen Sulfide Factors responsible for H 2 S production Elemental sulfur as a grape fungicide or sulfur candles used in barrel sanitation Musts deficient in assimilable nitrogen (FAN) levels By product of yeast stress metabolism Individual yeast strains produce differing levels of H 2 S Especially wild or natural yeast strains 24
Hydrogen Sulfide Factors responsible for H 2 S production High concentrations of insoluble solids Increased must ph Higher fermentation temperatures Hydrogen Sulfide Prevention: Avoid harvesting grapes prior to 6 weeks of the last sulfur application Use drip less sulfur sticks, sulfur dioxide gas or potassium metabisulfite for sterilization of tanks and barrels Addition of a yeast nutrient such as (DAP) and other essential amino acids such as in Fermaid K 25
Hydrogen Sulfide Prevention: Add appropriate amount of SO2 at crush Select a commercial strain shown to produce low amounts of hydrogen sulfide Clarify juice lowering the amount of solids Control fermentation temperatures Aerate fermenting must / juice during growth phase Rack of lees when detected Hydrogen Sulfide Remedy: If detected shortly after alcoholic fermentation try racking or sparging with carbon dioxide or nitrogen Try racking combined with the addition of sulfur dioxide (25 ppm) settle for one week and filtrate 26
Hydrogen Sulfide Remedy: New product Redulees (Lallemand) has been shown to reduce H 2 S Has Bentonite and other natural elements with Copper Bench trials essential The addition of copper sulfate as a fining agent Bench trials should be performed TTB limits of.5 ppm residual copper in finished wine Further Reduction of H 2 S Further reduction of H2S can form: Mercaptan: (Ethyl and Methyl) Can be remedied with copper sulfate and or ascorbic acid followed by copper sulfate Disulfide: Copper sulfate fining not possible Bench trials should be performed! 27
H 2 S Tasting Room Information Varies from loss of varietal fruit, slightly reduced to repulsive odor Represents a whole tank issue If suspected, pull from shelf and notify tasting room manager, winery owner or winemaker immediately for second opinion A penny in the glass or quick CuSO4 trial can help diagnose the problem Wine Flaws Tasting Room Overview Observe wine for 1) appearance 2) aroma 3) taste 4) aftertaste and 5) overall impression in performing sensory evaluation of wines prior to serving customers each day Limit perfume and cologne from affecting sensory evaluation of tasting room staff and consumers 28
Wine Flaws Tasting Room Overview Designate a sensory evaluation room separate from distractions and environmental smells with good incandescent lighting for proper sensory evaluation Keep training your palate by trying new varieties Wine Flaws Tasting Room Overview Avoid varietal racism Consumers (Millenials) are willing to dry different varieties Don t turn customers away by your preferences Become familiar with key sensory descriptors for each variety Appear knowledgeable across all consumer palates Develop some winemaking knowledge and terminology 29
Wine Flaws Tasting Room Overview It is important to bring suspect flaws to the attention of the winery owner / winemaker since this can be a potential problem for further contamination in the cellar based on the specific defect Recognition of these flaws can also be important in control and prevention for future vintages Wine Flaws Tasting Room Overview Tasting room staff represent the last quality control opportunity of wine prior to leaving the winery The quality of wine in the bottle directly affects the wineries perception 30
THANK YOU! Todd Steiner Enology Outreach Specialist OARDC Dept. Of Horticulture & Crop Science Phone: (330) 263-3881 E-mail: steiner.4@osu.edu 31