Making white wine
How hard can it be?
Whites:
sugar (ºBrix) range 19.5 – 24 pH 3.2-3.5 TA 7 to 8.5 grapes pressed before fermentation minimal skin contact juice prone to oxidation fermented cool
Temperature is critical
pick early keep grapes cool 50ppm may retard ML
Why skin contact? Pro: varietal character, tannin Con: astringency 2 to 24 hours keep cool 18 F is harmful stir daily
Yeast Nutrients
Why yeast nutrients?
nutrients often growth-limiting H2S, VA and stuck fermentations Fermaid K (Scott), Nutriferm Advance (Enartis) 1 g/gal @ ⅓ sugar depletion, or ½ at first bubbles and ½ @ ⅓ sugar do not add later
Other nutrients:
Booster Blanc, ICV Noblesse Use with DAP or Fermaid K
Photo:Wikipedia
Fermentation
keep temp below 60F stir daily: suspend yeast, aerate, release volatile sulfur cmpds. monitor for off-aromas can add oak cubes, chips, or ferment in barrel oak improves structure, mouthfeel
End of fermentation:
clarification hydrometer: 0 ºBrix still sugar dry: 0.2 to 0.3 ºBrix rack if wine will not be aged sur-lie check for off-aromas measure pH and TA add SO2 or add ML
Malolactic ‘fermentation’
reduce acidity typically chardonnay avoid SO2 after primary Enoferm Alpha will work at temperatures >55º F and tolerate up to 50 ppm (total) of SO2 Enartis: ML One, ML Silver Lysozyme: prevent or stop ML
innoculate with ML hydrate freeze-dried bacteria in water add a nutrient: ActiML or Nutriferm ML stir weekly
Aging sur-lie:
aroma, structure, protects from oxidation and imparts yeasty aroma lees must smell OK option: Surli ® (Enartis) products to substitute for lees 2 to 8 weeks stir 3-4 times a week (first month) stir 1-2 times/week thereafter
smell and taste at each stirring rack−off-aromas, desired character achieved maintain SO2 unless wine is undergoing ML rack 2 to 3 times top barrels purge with inert gas
Aging (élévage)
most whites 6 – 8 months stirring monitoring SO2 tasting, smelling topping clarification (racking) temperature
Ageing: options tannins fine: haze, browning, reduction, bitterness, astringency, heat stability polysaccharides (Enartis: Surli Elevage) − more stable cold stabilize wine (>40F for 4-5 days) filtering
Structuring tannins:
improve structure antioxidant fruit and aroma, softness unstable proteins examples: Enartis: Tanenol Fruitan, Elegance
Why filtering:
stability: minimize deposits remove yeast and spoilage bacteria taste, cleaner more focused appearance−polish stripping?
Sulfite levels:
top barrels, containers minimal head-space purge with inert gas avoid SO2 during MLF, add when complete test monthly: - 30-35 ppm most whites - 45 ppm above 3.5
Fining:
reduced aroma: CuSO2 bitterness: Bentonite and casein (Bentolact S), casein, PVPP, isinglass Herbaceous: isinglass, Colle perle (Scott) astringency (tannins): gelatins heat stability (proteins): Bentonite cloudiness: Sparkaloid or isinglass thin mouth feel: gum arabic
Cold stability
Expose to cold temp for 3 to 4 days Gum arabic Enartis: Citrogum
Final adjustment:
acid sugar sorbate .1 to .2 g/liter (19 to 38 g/5 gal.) SO2 Lysozyme gum arabic
wine stability mouthfeel− softness reduces bitterness sense of sweetness tartrate stability
Corks: natural or synthetic