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Avoiding the need to fine white wines
-Tailor skin contact time and temperature to grape-In high terpene varietals glycosidic enzymes can contribute to course texture-High alcohols exacerbate harsh phenolics-Use a high polysaccharide-producing yeast-Judicious use of barrels and enological tannins -Lees management – Lees fine, use of glucanase, delay racking to maximize mannoproteins, polysaccharides-Too much acid can negatively affect texture-Oxidation management-Delay heat and cold stability for max lees benefit
Red Wine Management
-Pick at low catechin levels-0 to 100% berry crush – usually at least 50% for most Paso Robles fruit-Press early for tannic varietals-Seed removal during pumpover-Judicious use of oak alternatives and enological tannins-Aerative rack to barrels-Splash into receiving tank from the press-Periodic racking to soften tannins-Treat sulfides during or immediately after fermentation
White Skin
Influence
FINING FOR BALANCE
Maximum fruit expression
Well-textured but not coarse
Compounds T – 0 hours (17oC)
T- 5 hours (17oC)
T- 22 hrs (17oC)
Sig LSDs
Methanol 34a 42a 58b *** 9.67
1-Hexanol (herbaceious/woody) 1.49a 1.64b 1.65b ** 0.092
2-phenyl-ethanol 16.77a 20.64b 19.75b *** 1.23
Ethyl acetate (sweet, solvent) 31a 40b 48c *** 7.90
Isoamyl acetate (banana, pear) 0.772a 0.543b 19.75b *** 1.23
2-phenyl ethyl acetate 0.083a 0.116a 0.026b ** 0.048
Ethyl butyrate (fruity, orange) 0.335a 0.765b 0.491c *** 0.148
Ethyl octanoate 1.08a 1.24ab 1.37b * 0.223
Ethyl decanoate 0.124a 0.030b 0.137a ** 0.071
Ethyl lactate (creamy) 33.57a 21.27b 24.25c *** 1.10
Isobutyric acid 0.550a 1.25b 1.08b *** 0.205
Butyric acid (goat, sheep, bison milk)
2.04a 2.78ab 3.64b ** 0.908
Hexanoic acid 6.25a 7.02b 8.34c *** 0.300
Octanoic acid 7.05a 7.45a 8.75b *** 0.446
Skin Contact - Treixadura – Portugal - Falque and Fernandez, 1996
Fruity flavor increase of Spanish Airén white wines made by brief fermentation skin contact.
The wines fermented with skins contained higher concentrations of methanol, proline, ethyl acetate, glycerol and ashes than did those fermented without skins.
The sensory profile method showed a considerable improvement in the fruity flavor as a result of mild maceration with the skins during the first 48 hours of fermentation of Airén wines.
Garcia-Romero et al, Universidad Castilla-La Mancha, 1999
Chardonnay wines with 0, 5.3, 10.7 & 16 hours pomace contact at 55oF. Phenolics, expressed as total, flavonoid or nonflavonoid, increased linearly (p < 0.001).The "total" aroma increased significantly (p < 0.001) with skin contact time, the 16-hour sample being rated the highest. The "fruity" aroma increased as well, but was lowest in the 5.3-hour treatment. No significant differences in bitterness or astringency were found among the four contact times.Arnold & Noble 1979
Chardonnay pomace contact (0, 6, 12 & 24 hrs at 59oF) showed no significant differences for fruit intensity, bitterness or acidity (N blanket during SC)Test, Noble et al 1986
Pomace contact (4 hrs at 59oF) showed increased aroma intensity for Chardonnay but not Grenache blancCheynier et al 1989
Whole Cluster or Crush?
Chardonnay – Whole Cluster or de-stem/crush/cold depending on stylePinot Gris – probably de-stem/crush/cold – Fining TrialsSauvignon Blanc – De-stem/crush/cold - Fining TrialsGewurztraminer – De-stem/crush/cold - Fining Trials (try gelatin)Viognier – Whole ClusterAlbarino – probably de-stem/crush/cold – Fining TrialsVermentino - probably de-stem/crush/cold – Fining TrialsGrenache Blanc - Whole cluster
Research needed
Optimal skin contact time by varietal for whites – focusing also on the question of crush or whole cluster
Then develop: Predictive modeling based on things we can measure like Brix at flavor peak, terpenes, flavor precursors, catechins/tannin assay
Frequently Used Fining Agents:
Isinglass/Silica GelBentonite – sine qua non for the presentCopper sulfateCaseinGelatinLees/Yeast PVPP Albumin
Frequently Used Fining Agents:
Isinglass/Silica GelBentonite – sine qua non for the presentCopper sulfateCaseinGelatinLees/Yeast PVPP Albumin
Useful Publication from Jim Harbertson at WSU:
‘A Guide to the Fining of Wine’
Thank youSigne Zoller
Zoller Wine [email protected]
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