The Role of Enzymes in Wine Making - an

overviewGlenn Curtis

Widmer Wine Cellars

32nd Annual NY Wine Industry WorkshopApril 2nd, 2003

Glenn Curtis is currently the Senior Winemaker and Winemaking Operations Manager at Widmer Wine Cellars. He has been with the winery since 1979 and has worked as Laboratory and Quality Manager, Assistant Winemaker and Winemaker. He has directed the growth in winemaking volumes at the winery from 200,000 cases in 1986 to 4,000,0000 cases in 2003. He oversees all winemaking operations, conducts research trials and produces the Brickstone brand of premium wines.

Enzyme: Definition

• “A Complex protein produced by living cells that promotes a specific biochemical reaction by acting as a catalyst”

• “It has become quite a common proverb that in wine there is truth” ….. Pliny the Elder, 1st C., A.D.

• “A tool that helps the wine maker bring out the truth of the grape in his/her wine”.

Enzymes: What are they?

• Most commercial enzymes are a mixture of different enzymes which can contain pectin esterase, polygalacturonase, pectin lyase, hemicellulase and cellulase

• Most enzyme preparations can also contain side activities

Enzymes: Side Activities

• Low in cinnamyl esterase: reduces chance of creating cinnamic acid from phenolic precursors which can be converted to vinyl-4-phenol

• Beta-glucosidase activity: cleaves bound terpenols from sugar. Terpenols are non-volatile precursors of aromatic compounds found in varieties like Riesling, Tramintte, Gewürztraminer and others.

Enzymes: Side Activities

• Protease activity: break down cell walls to extract anthocyanins, polymeric phenols and tannins to enhance color and structure

• Beta-glucanase activity: reduce beta-glucans from botrytised grapes to increase clarity and filterability. Made from Trichoderma, available in the E.U. but not the U.S.

Enzymes: Why use them?• Increase juice yield> Very effective in labrusca varieties (3-5% increase)

> Some what effective in hybrid varieties (+2-3%)

> Less effective in vinifera varieties (less than +2%)

• Increase clarification

• Increase filterability or reduces need to filter

• Increase color extraction and stability

• Increase complexity and mouthfeel

Enzymes: Points to consider for general use

• If using strictly for depectinization, buy on cost and learn variety characteristics: (Niagara at 12-14 Brix use 2oz/ton, over 14 Brix use 3oz/ton. Seyval 1oz/ton regardless of ripeness)

• Try to compare activity levels ( AJDU, FDU, etc)• Timing of additions: must, juice, wine• SO2 can inhibit activity• Low temp. and Alcohol can inhibit activity• Bentonite can inactivate enzymes

Enzymes: Points to consider for using “macerating enzymes’

• Usage rate depends on grape cell wall maturity which varies by variety and vintage.

• Taste grapes and look at skin and seed maturity. Higher doses with immature seeds can cause problems

• Try lower dosages on varieties with a high ratio of seed tannins ( Pinot Noir )

Enzymes: Points to consider for using “macerating enzymes’

• Take into consideration cap management program:

> If using gentle system like “punch down”, may be able to use lower dosage and increase skin contact time.

> If using more extractive system of “pump over”, may use higher dosage and shorten skin contact time, press off before completion of alcoholic fermentation

Enzymes: Points to consider for using “macerating enzymes’

• Enzymes only enhance compounds already there, if grapes lacking in anthocyanins or tannins, color extraction will be minimal.

• Look at using tannin additions in conjunction with enzyme additions, Right combination at the right time can have synergistic benefit's.

Enzymes: Points to consider for using “macerating enzymes’

• Consider “style” of wine you want to produce: is it an early release wine, popular priced, oak additions or is it a premium priced, long barrel aging, needs time to develop wine?

• Take into consideration yeast strain(s) being used, some are more extractive than others

• Do multiple enzyme, variety, vintage testing to develop a base line for what works for you!

Enzymes: Points to consider for testing enzyme preparations

• Always have a control, either no enzyme or your “standard” enzyme you use all the time

• Only change 1 parameter in each test lot

• Use as homogenous a fruit selection as possible, same vineyard block, harvest date.

• Use a single, selected yeast strain, no “natural selection” fermentation's

Enzymes: Points to consider for testing enzyme preparations

• Use consistent wine making practices, same fermentation temperature, cap management, pressing, racking, SO2 additions, ML inoculations.

• Bottle up enough samples after fermentation and taste and analyze over a set period of time

• If want to see barrel aging effect, use same oak, cooper, age of barrel and replicate (minimum of 4 barrels)

2000 Pinot Noir Color (520+420um)

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No EnzymeECT (30g/t)EVG (30g/t)

2000 Pinot Noir Tasting Panel(preference score 1-3 with “3” highest)

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2001 Pinot Noir Color (520+420um)

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2001 Pinot Noir Tasting Panel(preference score 1-3 with “3” highest)

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2002 Pinot Noir Color (520+420um)

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No EnzymeEVG (15g/t)EVG (30g/t)

2002 Pinot Noir Tasting Panel(preference score 1-3 with “3” highest)

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No EnzymeEVG (15g/t)EVG (30g/t)

Q & A