Presentation on theme: "Introduction to Winemaking Part 6: White Wines"— Presentation transcript:
1 Introduction to Winemaking Part 6: White Wines Dr. James HarbertsonExtension EnologistWashington State University
2 White Winemaking Techniques Cool FermentationProtection from oxidationMinimization of skin and seed contact timeDirect to pressEnzyme additionBarrel FermentationTank FermentationSecondary FermentationDry or SweetBlending
3 Cool FermentationMost whites are fermented at low temperatures (13 to 21C)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 reactionsBrowning 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 exposureAdd SO2 to inhibit enzyme activityKeep temperature low to slow reactions
5 Barrel FermentationTemperature is fairly low- small volume allows good heat dissipationExtraction 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 FermentationLower temperature to 5 CCentrifugeSterile Filtration (0.45 micron pore filter)Late Harvest grapesMoldy grapesBlend with concentrate
7 Botrytis Botrytis cinera is a mold that attacks grapes (noble rot) Under right conditions (high humidity, cracked grapes) the spores will germinateGrapes lose water without gaining raisin flavorAcidity does not change a lotYields grapes with high brix (30 and above)Concentrates grapes flavors, mold characterHigh production costs for artificial innoculation
8 Blending Keeping lots separate gives greater options The same or different varieties can be blendedWhere 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 exposureTemperature can be dropped to arrest fermentation for sweet winesNo oak componentsBetter control of MLSteel barrels can also be used
10 White Wine Styles Dry White Wines High Acid Generally Cool Climate Full-Bodied, Wood Aged White WineBarrel FermentedAromatic White WineCan be sweet
11 France as ExampleFrance will be used as a model to demonstrate different wine styles and winemaking techniquesDifferent regions of France will be discussedDetails of legal system will be omittedBurgundy 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 characterChaptalizationHigh AcidBarrel Fermented/wMLOak AgedSur Lies Aging
14 Chablis Cool Climate with “best vineyards” chalk and clay soil. ChardonnayDry White apple, pineapple with “mineral character” flavorsUse 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 MLProtected from oxidationStored in old oak tanks or steel tanksBlended to taste
17 Sauternes Sauvignon blanc and Semillon (mostly Semillon) Botrytis infected sweet winesSeasonal: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.