1. Introduction to Winemaking Part 6: White Wines
Dr. James Harbertson
Extension Enologist
Washington State University

2. White Winemaking Techniques
Cool Fermentation
Protection from oxidation
Minimization of skin and seed contact time
Direct to press
Enzyme addition
Barrel Fermentation
Tank Fermentation
Secondary Fermentation
Dry or Sweet
Blending

3. Cool Fermentation
Most whites are fermented at low temperatures (13 to 21C)
Minimizes loss of volatile flavor compounds that can occur with rapid CO2 generation.
Fermentation is generally longer and slower because of low temperature and lower yeast nutrient (pulp, skins and seeds absent).
Cool temperatures slow oxidative reactions

4. Protection from Oxidation
Oxygen is necessary component for browning reactions
Browning occurs when a grape enzyme reacts with phenolic compounds found in pulp, skin and seed and oxygen to produce brown compounds.
Minimize skin and seed contact, press early or skip crushing and go “direct to press”
Minimize oxygen exposure
Add SO2 to inhibit enzyme activity
Keep temperature low to slow reactions

5. Barrel Fermentation
Temperature is fairly low- small volume allows good heat dissipation
Extraction of barrel components (vanilla and toast characters are desired). (Age of barrel matters)
Undergo ML in barrel and gain buttery and creamy aspect.
Can age on lies longer 6 months to year to gain yeast characters (sur lies aging)

6. Dry or Sweet?
Fermentation to dryness or arrest fermentation to leave residual sugar (RS)
Arrest Fermentation
Lower temperature to 5 C
Centrifuge
Sterile Filtration (0.45 micron pore filter)
Late Harvest grapes
Moldy grapes
Blend with concentrate

7. Botrytis Botrytis cinera is a mold that attacks grapes (noble rot)
Under right conditions (high humidity, cracked grapes) the spores will germinate
Grapes lose water without gaining raisin flavor
Acidity does not change a lot
Yields grapes with high brix (30 and above)
Concentrates grapes flavors, mold character
High production costs for artificial innoculation

8. Blending Keeping lots separate gives greater options
The same or different varieties can be blended
Where science and art intermingle (The whole is often greater than the sum of the parts)
Allows for larger volume of more uniform wine and complex wine.
In practice small scale blends made up and tasted and %’s refined.

9. Tank Fermentation Allows good temperature control
Control of oxygen exposure
Temperature can be dropped to arrest fermentation for sweet wines
No oak components
Better control of ML
Steel barrels can also be used

10. White Wine Styles Dry White Wines High Acid Generally Cool Climate
Full-Bodied, Wood Aged White Wine
Barrel Fermented
Aromatic White Wine
Can be sweet

11. France as Example
France will be used as a model to demonstrate different wine styles and winemaking techniques
Different regions of France will be discussed
Details of legal system will be omitted
Burgundy and Bordeaux will be discussed for whites and Rhone will be added for reds.

13. White Burgundies Cool Climate Chardonnay
Dry White (apple, pear) with oak and ML character
Chaptalization
High Acid
Barrel Fermented/wML
Oak Aged
Sur Lies Aging

14. Chablis Cool Climate with “best vineyards” chalk and clay soil.
Chardonnay
Dry White apple, pineapple with “mineral character” flavors
Use steel jacketed tanks to control fermentation temperature.
Some are aged in old oak vats post ML or only in steel tanks.

15. White Bordeaux Wine Primarily Sauvignon blanc with Semillon
Sauvignon blanc is dry with grassy-vegetal aromas, also fruity.
Semillon is dry with honey and candied fruit aromas.
Semillon is blended with Sauv. blanc to add body and age-ability.

16. White Bordeaux II Fermented in Tank with temperature control
Fermented to dryness No ML
Protected from oxidation
Stored in old oak tanks or steel tanks
Blended to taste

17. Sauternes Sauvignon blanc and Semillon (mostly Semillon)
Botrytis infected sweet wines
Seasonal:High humidity to encourage mold growth followed by dry period for shriveled berries.
EtOH ranges from 12-14% while RS ranges from 5-15%
Golden wines age well with flavors of apricot, peach, pineapple and vanilla.