Michael Sipowicz Texas Custom Wine Works

 Specifics regarding each variety  Generalities which apply to a broader group

 Central Florida Research and Education Center in 1968  Released 1987 (Mortensen 1987)  Little is known about the flavor characteristics or volatiles

A Study of Blanc Du Bois Wine Quality E. Dreyer, Charles Sims, Russell Rouseff, Dennis Gray, and Michael Sipowicz Am. J. Enol. Vitic. 64:1 (2013) The objective of this study determine: Sensory characteristics Flavor volatiles Chemical parameters Relationships between these Large, representative sample of Blanc Du Bois wines evaluated

A Study of Blanc Du Bois Wine Quality E. Dreyer, Charles Sims, Russell Rouseff, Dennis Gray, and Michael Sipowicz Am. J. Enol. Vitic. 64:1 (2013) Seventeen different wines 100% Blanc du Bois Vintages 2006, 2007 & 2008

A Study of Blanc Du Bois Wine Quality E. Dreyer, Charles Sims, Russell Rouseff, Dennis Gray, and Michael Sipowicz Am. J. Enol. Vitic. 64:1 (2013) Wine Quality Evaluation Florida State Fair 21st Annual Wine and Grape Juice Competition in Evaluated by 26 experienced judges Descriptive Analysis 16 Trained panelist Chemical Analysis six replications for each wine

Principal component analysis (PCA) was run to help visualize differences among the wines and how quality might be influenced by those differences. There are two general categories under which these Blanc Du Bois wines fall

Wines 9, 13-highest for phenolic/rubber Wines 9, 12, and 13-highest means for bitter and greenwood/stemmy character intensity. Sweetest wines (6, 7) had greater than 4% residual sugar, grouped with sweet and honey attributes. Wines 2 and 3 appeared to be heavily influenced by their titratable acidities and high citrus character Three other high quality wines (1, 4, 5) grouped with the sweet, fruity, and floral attributes and opposite the greenwood/stemmy and phenolic/rubber attributes. Figure 2: PCA samples plot showing PC1 and PC2 for the DA attribute intensity data. Numbers indicate quality ranking of the wine, with 1 being highest quality.

Wines tended to have one of two flavor profiles:  Citrusy, bitter, and greenwood/stemmy wines  Contrast with wines possessing sweet, fruity, and floral attributes  Wines perceived as higher quality aligned with later group attributes

Correlation Analysis:  wine quality was positively correlated with peach and rose  negatively correlated with greenwood/stemmy, phenolic/rubber, bitter,  Strong correlation to Grapefruit & Lemon  The only volatile to correlate negatively with quality (p<0.10) was furfural

Furfural: Compounds result from degradation of sugars and carbohydrates by heat (Maillard reactions). *Consider not barrel aging or adding oak

Apple Overripe Tropical Peach Grapefruit Lemon Rose Honey Greenwood Phenolic/Rubber Sweet Sour Bitter Astringent Color TA pH Residual Sugar Quality Rating Apple 1.00 Overripe/Tropical 1.00 Peach Grapefruit Lemon Rose Honey Greenwood/Stemmy Phenolic/Rubber Sweet Sour Bitter Astringent Color TA 1.00 pH Residual Sugar Quality

Maximize: Fruity Aromatics Overripe Honey Minimize: Stemmy & Green Oaky Phenolic Rubber Bitter

 Yeast derived…  passion fruit, boxwood, grapefruit, cat pee and similar things favored in Sauvignon Blanc

 Fruit derived…  Bound with glucose. Sweet and floral to resinous and herbaceous

 Fruit derived…  Must be liberated.  Bottle aging (hydrolysis) – Accelerated with increase in temperature  Glycosidase Enzyme Treatment

 Use of pectic enzymes vs. bentonite for juice clarification  Proper pre-fermentation nutrient additions  Use bentonite in the fermentor for grape lots which have historically high post-fermentation stability requirements  Use of post-fermentation pectic (glycosidase) enzymes (Zoecklein, 2003)

Use of pectic enzymes vs. bentonite for juice clarification  Most commercial pectic enzymes have some level of glycosidases, the enzymes that can break the glycosidic bond, releasing bound aroma/flavor components +++  Glycosidases are capable of releasing aromatic terpenols from their non-aromatic precursors +++  Bentonite can adsorb large concentrations of ethyl and acetate esters, thus lowering aroma and aroma intensity - (Zoecklein 2003, Lourens et al. 2000)

Use of pectic enzymes vs. bentonite for juice clarification  Glycosidases are generally inhibited by small concentrations of glucose  Pre-fermentation aroma/flavor evolution will be minimal  Enzyme formulation will facilitate clarification of juice without the use of bentonite, with some aroma/flavor evolution potential (Lourens et al. 2000)

Proper pre-fermentation nutrient additions  Too much DAP can lower the production of esters  Nutrient deficiencies during fermentation can lead to unhealthy / stuck fermentation  Off flavors / aromas (Zoecklein, 2003)

Use bentonite in the fermentor for grapes which have historically high post-fermentation stability requirements (>2 lb/1000gals)  Bentonite can adsorb large concentrations of ethyl and acetate esters, thus lowering aroma and aroma intensity  Fermentation with bentonite requires the addition of fermentable nitrogen.  Bentonite use during fermentation will reduce (eliminate?) bentonite requirements post- fermentation (Zoecklein et al., 1995, 1999)

Use of post-fermentation pectic (glycosidase) enzymes  Some suggest that an enzyme should only used on part of a final blend as it is not desired that all the bound flavors are released into the volatile form  Monoterpenes are fairly stable molecules and are hydrolyzed over time, releasing a floral aroma over a long period of ageing.  Enzyme activity will release a lot of flavor/aromatics all at once.  By treating only a part of a blend, the rest of the blend will supply the flavors to enhance the longevity of the wine. ( Zoecklein, 2003 & Lourens et al )

Use of post-fermentation pectic (glycosidase) enzymes  Can be added to a finished wine or a wine with a residual sugar of 50 g/L or less  The enzyme action must be stopped after one to four months depending on the desired effect that is required. The enzymes have to be removed with Lbs/1000 gallons bentonite, or by precipitation with tannin phenols (preferred)  Bentonite can adsorb large concentrations of ethyl and acetate esters, thus lowering aroma and aroma intensity ( Zoecklein, 2003 & Lourens et al )

Use of post-fermentation pectic (glycosidase) enzymes  Not inhibited by the alcohol content of table wines  Much success with varieties such as Muscat, Gewürztraminer and Riesling  Sauvignon blanc and Chardonnay contain monoterpenes in addition to their specific varietal character. It is not always desirable for these grape varieties to have a terpene background aroma so glycosidase enzymes should be used carefully on these varieties ( Lourens et al )

Perception of Acidity - SUGAR + TANNINS + HERBACIOUSNESS, MP’s - POLYSACCHARIDES + INTENSITY OF TANNINS + BITTER / DRYING / ASTRINGENT

Perception of Acidity Palate Balance Equation Sweet Acid + Phenolics Carbohydrates Organic acids Skin, seed, and stem phenol Polysaccharides Barrel phenol Ethanol Enological tannins Volatile phenols

 Speed of Processing  Skin Contact WHITES- Atypical Phenolic Profile Astringency, Bitterness, Drying NZ “Kiwi” Style Sauvignon Blanc --Likely NOT Possible Utilizing Current Transport  Crush Protocols

 Length of Contact With Skins  Equal Opportunity Extraction  Transport,Fermentation & Maceration  Subjective Sugar, Polysaccharides, Body, Color, Aromas vs. Bitterness, Drying, Tannins

Perception of Phenols + ACID + HERBACIOUSNESS, MP’s - POLYSACCHARIDES, OTHER SUGARS + INTENSITY OF TANNINS + BITTER / DRYING / ASTRINGENT - ETHANOL (Up to 14%, + Above 14%) + VOLATILE SULFUR COMPOUNDS

Perception of Phenols Palate Balance Equation Sweet Acid + Phenolics Carbohydrates Organic acids Skin, seed, and stem phenol Polysaccharides Barrel phenol Ethanol Enological tannins Volatile phenols

Proper pre-fermentation nutrient additions  Too much DAP can lower the production of esters  Nutrient deficiencies during fermentation can lead to unhealthy / stuck fermentation  Off flavors / aromas (Zoecklein, 2003)

 MOG (materials other than grapes) removal & Stem separation  Properly functioning destemmer  Leaves in the fermenter can be a source of herbal character  Sensory differences dramatic between wines made with and without jack stem removal  Post-destemmer sorting tables

 Sort/Cull as much rot as possible.  An incidence level of only 1-3% can negatively influence quality depending on the extent and nature of the rot.  Larger yeast inoculation  High incidences of fungal degradation influence must nitrogen and micronutrients  Test pre-fermentation nutrient levels and adjust accordingly (Zoecklein, 1997)

 Consider whole cluster pressing whites vs crush and drain. Press lightly or segregate.  Cold settle using pectic enzymes and PVPP. The enzymes will help lower the non-soluble solids level.  The PVPP will help to bind some of the harsh, low molecular weight phenols which have been extracted due to the rot. Use up to 4 pounds/1000 gal PVPP (Zoecklein, 1997)

 Consider Hyper-oxygenation (Hyper-Ox)  Add ~15ppm Free SO2 (Reserves some O2 for Healthy Fermentation)  “Rake” Pan as Juice is Pressed Out ▪ or  Bubble air into receiving tank

 Consider Hyper-oxygenation (Hyper-Ox)  Juice will “Brown Out”  PPO will React with Phenols ▪ Leads to polymerization and Precipitation of Phenolics that contribute to Bitterness  Oxygen is a limiting factor in reaction  Don’t Over do it….Can lead to LOSS of aromatics ▪ 9mg/L O2 per Liter of Juice

….BALANCE Palate Balance Equation Sweet Acid + Phenolics Carbohydrates Organic acids Skin, seed, and stem phenol Polysaccharides Barrel phenol Ethanol Enological tannins Volatile phenols

Lenoir  Very Old Wine Grape Variety  Heritage Unknown  Believed to be a V. aestivalis / V. vinifera hybrid

 By many is considered Inferior to more mainstream European Varieties due to an Atypical Aromatic/Flavor Profile  Influenced by Production Practices?

Issues  Color stability  “Odd” or “Off” flavor  “Animal” or Vinyl Phenol Aromas  Poor structure

Based On:  Years of Winemaker’s Experience  Anecdotal Evidence  Numerous Sensory Trials

Aroma / Flavor Trait Appears to be Affected By:  Fermentation Temperature  pH  Yeast and as Well Malolactic Bacteria Strains  Presence of Other Grape Varieties  Some Suspicion That Vinylphenols Involved

 Controlled Environment  Lab Fermentation Trials--Common Red Winemaking Protocols  Find Correlations  Sensory Evaluation and Analysis  Recommendations

 Warm Lots Fermented  90-95ºF  Cool Lots Fermented  75-80ºF

 COLOR

 pH

VARIETAL CHARACTER / ATYPICAL AROMA

Vinylphenols Are Produced By   Hydroxycinnamate decarboxylase (HCDC)   Decarboxylation of p-coumeric acid   (others too)   Many Yeast and Bacteria Have Varying Degrees of HCDC Activity

 HCDC Activity Increases as Temperature Increases  Incidentally as pH Increases

  Vinylphenols React With Anthocyanins   (mainly malvidin-3-O-glucoside)   In Vitis vinifera   Results in Vinylphenolic Pyranoanthocyanin   VERY Stable Color   Non-Aromatic Product

  Many Anthocyanins Unique to Black Spanish   Lower Occurrence of Malvidin-3-O-Glucoside Than European Varieties

  Vinylphenols React With Anthocyanins   (mainly malvidin-3-O-glucoside)   In Vitis vinifera   Results in Vinylphenolic Pyranoanthocyanin   VERY Stable Color   Non-Aromatic Product

 Options:  Prevent / Inhibit Vinylphenol formation  Increase Anthocyanins in fermentation to form non-aromatic aducts

Options:   Prevent / Inhibit Vinylphenol formation   “Cinn- Free”( cinnamoyl esterase negative) Yeast and ML bugs   Some yeasts:   T73, V1116/K1, BM4X4, ICV Opale, CSM, Steinberger/DGI 288   Some ML bacteria:   CH11, CH16, CH35 and Oenos 2.0   Cinnamoyl esterase negative Enzymes Too!

Options:   Increase Anthocyanins in fermentation to form non-aromatic aducts   Co-Fermentation / Addition of Concentrates

 Cooler Fermentations  Avoid ML Fermentation or use cinnamoyl esterase negative selections  Keep pH Lower  On Skins  Promote active oxygen species in fermentation  Addition of ellagitannin can enhance formation of stable wine pigments (vitisinA)

 Speed of Processing  Skin Contact Potassium Content of Fruit K+ will exchange one-to- one with H+ pH

Length of Contact With Skins  pH / K+ Relationship  Fermentation & Maceration  Subjective ++Bitterness, Drying, Tannins & Tannin Intensity - - Sugar, Polysaccharides, Body

Malolactic Fermentation ML units g/L pH TA

Volatile Acidity a.k.a. VA Acetic Acid- <400mg/L normal in New Wine (Dry) ++ Vineyard Yeasts ---Rapid Processing +++ Acetobacter aceti ---Needs O 2 ---Not a fan of SO 2 U.S. legal limits: Red Table Wine 1.2 g/L White Table Wine 1.1 g/L

Adjustments  Acid Additions  Deacidification  Carbonates  Ion Exchange  Other-Specialized Yeast, Carbonic Maceration, etc.

Perception of Acidity - SUGAR + TANNINS + HERBACIOUSNESS, MP’s - POLYSACCHARIDES + INTENSITY OF TANNINS + BITTER / DRYING / ASTRINGENT

Perception of Acidity Palate Balance Equation Sweet Acid + Phenolics Carbohydrates Organic acids Skin, seed, and stem phenol Polysaccharides Barrel phenol Ethanol Enological tannins Volatile phenols

Harvest Timing  Warm Climate Grape Growing Hang Time USUALLY NO PROBLEM “SUGARING UP” Sugar

Speed of Processing -- Grape Berry Microflora Yeasts, Molds and Bacteria 95-98% of Total are Bacteria and Molds Directly Compete with Desirable Yeast Pitch for Nutrients and Carbon Source

Speed of Processing Inside wall 1/3 insideMiddle Malic2.13 g/L1.93 g/L0.13 g/L Lactic0.23 g/L00 Ethanol0.13 %1.93 %4.97% Brix Analysis of Machine Harvested Grapes Samples were taken after transport. Table shows the change in malic acid, lactic acid, ethanol and brix after transport. Based on these and other data there is considerable fermentation occurring during transport. --Cobb, 2007

Adjustments --Chaptalization 27 CFR PART 24--Subpart F--Production of Wine § Chaptalization (Brix adjustment). “…sugar, or concentrated juice of the same kind of fruit may be added before or during fermentation to develop alcohol. The quantity of sugar or concentrated juice added may not raise the original density of the juice above 25 degrees Brix.”

Adjustments --Chaptalization Cane Sugar --- Gets the Job Done --- “Donut Hole” Wine Grape Concentrate --- Varietal grape Concentrates, MegaPurple, Ultra Red, etc…

Perception of Sweetness - TANNINS - HERBACIOUSNESS, MP’s + POLYSACCHARIDES, OTHER SUGARS - INTENSITY OF TANNINS - BITTER / DRYING / ASTRINGENT + ETHANOL - VOLATILE SULFUR COMPOUNDS - ACIDS

Perception of Sweetness Palate Balance Equation Sweet Acid + Phenolics Carbohydrates Organic acids Skin, seed, and stem phenol Polysaccharides Barrel phenol Ethanol Enological tannins Volatile phenols

Phenolics, Skin, Seed, and Stem Phenol, Barrel Phenol, Enological tannins, Volatile phenols, Tannin Intensity, Astringency, Bitterness, Drying, Green Herbaciousness, MP’s PHENOLS

Harvest Timing Ripe vs. “Mature” “Fruit at the Desirable Brix” vs. Stems and Seeds Brown with Developed Aromatics

Speed of Processing - MOG  Methoxypyrazine, IBMP  (2-methoxy-3-isobutylpyrazine), imparts a vegetal aroma at relatively low concentrations in the fruit, ranging from zero to 35 ng/L.  Present in green plant tissues, including grapes.  Perceptible at 1 ng/L (1 part per billion)

Speed of Processing - MOG  Methoxypyrazine, IBMP  IBMP are VERY easily liberated into the juice

 Speed of Processing  Skin Contact WHITES- Atypical Phenolic Profile Astringency, Bitterness, Drying NZ “Kiwi” Style Sauvignon Blanc --Likely NOT Possible Utilizing Current Transport  Crush Protocols

 Length of Contact With Skins  Equal Opportunity Extraction  Transport,Fermentation & Maceration  Subjective Sugar, Polysaccharides, Body, Color, Aromas vs. Bitterness, Drying, Tannins

Adjustments  Extended Maceration vs. Short-Vatting  Oak Barrel Aging and Oak Additives  Enological Tannins  Proteinaceous Fining-  Egg White, Isinglass, Casein  Long Chain- Astringency  Gelatine, PVPP  Short Chain-Bitter  R.S. or Polysaccharides  Deacidification?

Perception of Phenols + ACID + HERBACIOUSNESS, MP’s - POLYSACCHARIDES, OTHER SUGARS + INTENSITY OF TANNINS + BITTER / DRYING / ASTRINGENT - ETHANOL (Up to 14%, + Above 14%) + VOLATILE SULFUR COMPOUNDS

Perception of Phenols Palate Balance Equation Sweet Acid + Phenolics Carbohydrates Organic acids Skin, seed, and stem phenol Polysaccharides Barrel phenol Ethanol Enological tannins Volatile phenols

Targeted aroma & taste characteristics :  Healthy Vines  Optimum Maturity Level  Varying Levels of Maturity Per Variety Example: Cabernet Sauvignon- dark cherry, black berry, black current, etc.

Harvest Timing Ripe vs. “Mature” “Fruit at the Desirable Brix” vs. Stems and Seeds Brown with Developed Aromatics

Harvest Timing- Elevated MP’s  Seed tannins make up over 60% of the total tannin concentration seeds (31%),  Pyrazines, such as IBMP, are found in stems (53%), seeds (31%), skins (15%), and flesh (1%)

Reds- Reds- saignée or “bleeding”  Increases ratio of skins to juice within tank  Concentrates and increases red wine varietal character  Concentrates and increases red wine body, structural depth and color potential  Yields secondary product: Rosé de saignée  Rosé produced from red grapes that undergo a short maceration acquiring some color.  Stylistically “bigger” than rosés de pressurage

Proper pre-fermentation nutrient additions  Too much DAP can lower the production of esters  Nutrient deficiencies during fermentation can lead to unhealthy / stuck fermentation  Off flavors / aromas (Zoecklein, 2003)

 MOG (materials other than grapes) removal & Stem separation  Properly functioning destemmer  Leaves in the fermenter can be a source of herbal character  Sensory differences dramatic between wines made with and without jack stem removal  Post-destemmer sorting tables

 Cap management  Gentle practices, minimize excessive extractions  Short Vatting- selective extraction  Délestage  Seed deportation  it must be gentle, and extremely gentle beyond mid- fermentation

Cap management Short Vatting- Selective extraction by dejuicing prior to dryness Traditional short vatting: Rapid diffusion of desirable pigments, tannins and polysaccharides from the skins and the pulp, and the stabilization of phenols and aromatic compounds (Delteil, 2000).

Cap management Délestage  Délestage, with or without seed deportation, allows for fairly rapid diffusion without over-extraction.

Cap management Délestage

(DELTEIL 2003) Only pumping over, 15 days maceration 7 Délestages during a 15 days maceration

 Oxygenation: Barrel aging, rack-splash operations, Microoxidation  Oxidation of some sulfur-containing compounds may result in the muting of the varietal character of treated wines.  Seems a result of changes in peripheral compounds which enforce sensory perception (Zoecklein, Sullivan 2002)

 Sort/Cull as much rot as possible.  An incidence level of only 1-3% can negatively influence quality depending on the extent and nature of the rot.  Larger yeast inoculation  High incidences of fungal degradation influence must nitrogen and micronutrients  Test pre-fermentation nutrient levels and adjust accordingly (Zoecklein, 1997)

….BALANCE Palate Balance Equation Sweet Acid + Phenolics Carbohydrates Organic acids Skin, seed, and stem phenol Polysaccharides Barrel phenol Ethanol Enological tannins Volatile phenols

 Other considerations:  Run pre-fermentation nutrient analysis!!!  Native yeast/bacteria, fruit rot, poor sanitation, long settlings, and delayed inoculation can deplete must nutrients, and may produce toxins. In such cases, the level of yeast inoculum should be increased, along with the fermentable N supplementation to a level of 250 mg/L N or more. (Zoecklein, 2005)

 Other considerations:  Sulfidic or Sulfur-Like Off-oder Testing  Gusmer has the Kit  DO IT!

Have A Grape Day! QUESTIONS?