Michael Sipowicz Texas Custom Wine Works [email protected]

Michael SipowiczTexas Custom Wine [email protected]

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 QualityE. Dreyer, Charles Sims, Russell Rouseff, Dennis Gray, and Michael

SipowiczAm. 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



• Seventeen different wines

• 100% Blanc du Bois

• Vintages 2006, 2007 & 2008



• Wine Quality Evaluation• Florida State Fair 21st Annual Wine and Grape Juice Competition in

2009.• 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 rosenegatively 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 ofsugars and carbohydrates by heat (Maillardreactions).

*Consider not barrel aging or adding oak

Maximize:Fruity AromaticsOverripe Honey

Minimize:Stemmy & Green OakyPhenolicRubberBitter

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)


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)


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. 2000)


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 .4 -.8 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. 2000)


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. 2000)

Perception of Acidity

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


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 CrushProtocols

Length of Contact With Skins Equal Opportunity Extraction Transport ,Fermentation &

Maceration SubjectiveSugar, Polysaccharides, Body,

Color, Aromasvs.

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



Sweet<-->

Acid + Phenolics

Carbohydrates

Organic acids


Polysaccharides

Barrel phenol


Volatile phenols

Proper pre-fermentation nutrient Proper pre-fermentation nutrient additionsadditions



MOG (materials other than grapes) MOG (materials other than grapes) removal & Stem separationremoval & 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


Sweet<-->

Acid + Phenolics

Carbohydrates

Organic acids


Polysaccharides

Barrel phenol


Volatile phenols

Lenoir

Very Old Wine Grape Variety

Heritage Unknown

Believed to be a V. aestivalis / V. viniferahybrid

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 AromasPoor 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

COOL FERM (C ) WARM FERM (H)

SKINS NO SKINS SKINS NO SKINS

ML 3 REPS 3 REPS 3 REPS 3 REPS

NO ML 3 REPS 3 REPS 3 REPS 3 REPS

Warm Lots Fermented 90-95ºF

Cool Lots Fermented 75-80ºF

COLOR

pH

VARIETAL CHARACTER / ATYPICAL AROMA

Vinylphenols Are Produced ByHydroxycinnamate 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 FermentationsAvoid ML Fermentation or use

cinnamoyl esterase negative selectionsKeep pH LowerOn SkinsPromote active oxygen species in

fermentation Addition of ellagitannin can enhance

formation of stable wine pigments (vitisinA)


• Potassium Content of Fruit

• K+ will exchange one-to-one with H+

pH

Length of Contact With SkinspH / K+ RelationshipFermentation & MacerationSubjective++Bitterness, Drying, Tannins & Tannin Intensity- - Sugar, Polysaccharides, Body

Malolactic Fermentation ML

0.1-0.3units 0.01-

0.03g/L

pH TA

Volatile Acidity a.k.a. VAAcetic Acid- <400mg/L normal in New Wine (Dry)++ Vineyard Yeasts ---Rapid Processing +++ Acetobacter aceti

---Needs O2 ---Not a fan of SO2

U.S. legal limits: Red Table Wine 1.2 g/LWhite Table Wine 1.1 g/L

Adjustments

Acid AdditionsDeacidification

Carbonates Ion Exchange Other-Specialized Yeast, Carbonic

Maceration, etc.


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



Sweet<-->

Acid + Phenolics

Carbohydrates

Organic acids


Polysaccharides

Barrel phenol


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 wall1/3 inside Middle

Malic 2.13 g/L 1.93 g/L 0.13 g/L

Lactic 0.23 g/L 0 0

Ethanol 0.13 % 1.93 % 4.97%

Brix 23.1 21.6 19.2

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§ 24.177 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


Sweet<-->

Acid + Phenolics

Carbohydrates

Organic acids


Polysaccharides

Barrel phenol


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 - MOGMethoxypyrazine, 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 - MOGMethoxypyrazine, IBMP

IBMP are VERY easily liberated into the juice


WHITES-Atypical Phenolic Profile

Astringency, Bitterness, Drying

NZ “Kiwi” Style Sauvignon Blanc --Likely NOT Possible Utilizing Current Transport CrushProtocols

Length of Contact With Skins Equal Opportunity Extraction Transport ,Fermentation &

Maceration SubjectiveSugar, Polysaccharides, Body,

Color, Aromasvs.

Bitterness, Drying, Tannins

AdjustmentsExtended Maceration vs. Short-VattingOak Barrel Aging and Oak AdditivesEnological TanninsProteinaceous Fining-

Egg White, Isinglass, Casein Long Chain-Astringency

Gelatine, PVPP Short Chain-BitterR.S. or PolysaccharidesDeacidification?


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



Sweet<-->

Acid + Phenolics

Carbohydrates

Organic acids


Polysaccharides

Barrel phenol


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

Pyrazines, such as IBMP, are found in stems (53%), seeds (31%),seeds (31%), skins (15%), and flesh (1%)

Reds- Reds- saignée or “bleeding”Increases ratio of skins to juice within tankConcentrates and increases red wine varietal characterConcentrates and increases red wine body, structural depth and color potentialYields 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 Proper pre-fermentation nutrient additionsadditions



MOG (materials other than grapes) MOG (materials other than grapes) removal & Stem separationremoval & 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 managementCap managementGentle practices, minimize excessive

extractions Short Vatting- selective extraction Délestage Seed deportation it must be gentle, and extremely gentle

beyond mid-fermentation

Cap managementCap managementShort 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 managementCap management

Délestage Délestage, with or without seed

deportation, allows for fairly rapid diffusion without over-extraction.

Cap managementCap managementDélestage

(DELTEIL 2003)

0

1

2

3

4

ICV

Scal

e

1. Foremouth volume 2. Acidity 3. Tannic Intensity4. Astringency 5. Dryness 6. Bitterness

0

1

2

3

4

ICV

Scal

e

1. Foremouth volume 2. Acidity 3. Tannic Intensity4. Astringency 5. Dryness 6. Bitterness

Only pumping over, 15 days maceration

Only pumping over, 15 days maceration

7 Délestages during a 15 days maceration

7 Délestages during a 15 days maceration

Oxygenation: Barrel aging, Oxygenation: Barrel aging, rack-splash operations, rack-splash operations, MicrooxidationMicrooxidation

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


Sweet<-->

Acid + Phenolics

Carbohydrates

Organic acids


Polysaccharides

Barrel phenol


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!Have A Grape Day!

QUESTIONS?QUESTIONS?

Documents

Michael Sipowicz Texas Custom Wine Works [email protected]