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47 Cards in this Set
- Front
- Back
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Potassium and pH |
High means higher pH, low means lower pH/higher TA |
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Thiamin |
-20% Juices deficient -Should add 50mg/L addition -Adding excess has no effect |
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Acidity changes during crystallization |
-TA goes down -pH change depends on buffer capacity |
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Freeze Test |
Hold at -2C for 1 day, thaw and look for KHT crystals |
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KHT cold test |
hold at 2C for 4-6 weeks, look for crystals |
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KHT Rate of Crystallization test |
-Set up ideal crystallization conditions and let it crystallize -Monitor changes to conductivity -Filter and get pH/TA to get final values |
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KHT Concentration product approach |
-Ignores pigmentation and complexing effects -Independent of age |
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Fast Heat test for protein stability |
90C for 1-2 hours or 80C for 4 hours |
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Slow heat test for protein stability |
50C for 2 days |
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Wine proteins |
-pI from 3-8.5 -Most are (+) at wine pH -MW of 20-0 kDaltons -33% are anionic |
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3 ways to remove metals |
-Metal Chelators like alginate and pectates -Metal depleting resins like Chelex -Yeast
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Polysaccharides |
-Mannoproteins -Alginates will break haze due to protective colloids |
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Activated carbon (3) |
-Adsorbs aroma, solutes -Non-selective -Removes color in young wines |
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Bentonite replacements |
-Regenerable bed of Macroprep (weak cation exchanger) -Hydroxyapitate support |
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Clays like Bentonite |
-Uses cation exchange capacity -Na form adsorbs more |
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Pectic enzymes |
-Require time/temperature for reaction -Earlier color extraction in reds -Possible Polysaccharide effects later |
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Deacidification, Single salt method |
-Direct addition -Increases Ca++ -CaTa stability later |
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Deacidification, Double salt method |
-Fractional addition -no Ca++ increases -has CaTa and some CaMa salts |
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Insoluble Synthetic Polymers |
-PVPP/Nylon -Can use column and regenerate -Removes anthocyanins, colored dimers -Reduces browning potential of flavanoids |
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Protective Colliods |
-Charged macromolecules that form complexes with metal cations -Measured in gold numbers |
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Fining Proteins (Casein, Albumin, Isinglass, Gelatin) |
-Deplete tannin and polymeric pigment -mimimal solubility ar wine pH due to pI |
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Initial Dissolve Oxygen |
-Essential for sterol synthesis in membranes -Need 4-8mg/L -Low makes for long lag phase -Affects cell viability at end of fermentation -Most important at high sugar, low temperature |
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Adsorption Sensory effects |
-Small capacity, easily saturated -Can have significant effects even with a small amount depleted |
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Freundlich |
-Large number of sites -Linear -Proteins, PVPP, Carbon |
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Langmuir |
-Fixed number of sites -Exponential -Bentonite, enzymes, Ion Exchange |
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Cork Closure Costs: Fine, Granulated, Synthetic, Synthetic Plugs |
-Fine: 50c -Granulated: 20c -Synthetics: 20c -Sunthetic Plugs: 70c |
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Diffusion |
-Independent of pressure -Temperature plays tiny role |
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Permeation |
-Due to pressure difference -Independent of concentration -Headspace pressure exponential with temperature |
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Aeration Oxidation |
-Reproducible but bad measure of free SO2 -Some bound SO2 appears in free measure |
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SO2 additions |
-50mg/L to juice to inhibit PPO -0.4-0.8mg/L molecular after fermentation -0.4mg/L molecular through aging -0.4-0.8mg/L molecular at bottling -25% added shows up as free |
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Thiols |
-Onion/Garlic aroma -Easily oxidized -Could be defect in bottle after 6 months |
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Alkyl Thio-acetates |
-Associated with elemental Sulfur in fermentation -Low volatility -Releases RSH -Could be bottle defect after 6 months |
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Dimethyl Sulfide |
-Canned corn aroma -Usually in red wine after age -Doesn't get Oxidized or precipitate with Cu++ -Thought to be present in grapes naturally |
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Removal methods: H2S RSH RSSR RSAc DMS |
H2S: CuSO4 RSH: CuSO4 RSSR: SO2, 6+ months later CuSO4 RSAc: Wait 12 months, CuSO4 DMS: None |
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Copigmentation definition |
-When anthocyanins stack -Enhances anthocyanin color via momomeric phenols (cofacotors) -4-10 times more colored when copigmented |
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Types of Cofactors |
-Cinnamates -Flavanols -Flavones |
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Copigmentation Significance |
-30-50% of color in young red wines -Involved with tartrate stability in young reds |
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Color Loss |
-Reds lose around half their color with age -Usually 20-40% after 6 months -Lose purple color with formation of polymeric pigment -Tartrate loss and cofactor oxidation causes loss of copigmented color |
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Forms of Oxygen |
-Dioxygen O2 -Superoxide Ion O2- -Hydroperoxyl Radical HOO -Hydrogen Peroxide HOOH -Hydroxyl Radical HO |
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Danilewicz Model |
Mechanism of autoxidation of polyphenols and participation of sulfite in wine |
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Acetaldehyde Formation |
Formation of acetaldehyde from peroxide and ethanol |
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SO2 at Bottling |
-Not for microbial protection -Free SO2 to bind up acetaldehyde formed after first few years aginig -SO2 will be lost via permiation, H2O2 reaction -Determines shelf life of wine along with closure -Slows browning in whites -Lowers redox potential at high levels |
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Proteins fine for |
-Tannin depletion -Preference for polymers |
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PVPP removes |
-Monomeric phenols -Anthocyanins -Reduces browning potential of flavanoids |
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Bentonite removes |
-Protein haze -Some off aromas |
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Activated Carbons remove |
-Phenols -Color -Tannins -Used for color removal in young wines |
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Alginate used for |
Breaks haze due to protective colloids |
