Mildew Protocols and Processes

White Grapes

• Vigorous sorting either in vineyard or crush deck
• Minimize crushing/destemming if possible
• 50-100 mg/L SO2 on fruit
  • Vary dosage rate depending on degree of fruit break down and juice pH
  • SO2 will not inactivate laccase, but will help minimize unwanted microbial populations
• 50-100 mg/L Gallic tannin (Galalcool/Gallovin) during press loading
  • Reinforces antioxidant potential of SO2
  • Binds with enzymes and proteins present in infected fruit/juice
• Low pressure pressing
  • Clarification or beta glucanase enzymes during pressing to help with quick extraction off skins
• Press fractioning
  • The first couple hundred litres can have highest concentrations of laccase/glucans and unwanted microbes. Keep separate from remaining press fraction.
  • Heavy pressing can be treated with the first couple hundred litres to reincorporate the infected juice to the main press fractions, or fermented and kept separately if infection is widespread.
• Limit O2 contact at all stages to minimize oxidative enzyme activity
  • Purging lines and tanks with CO2
  • CO2 cover in sitting bins, press trays, tank ullage
  • Limit movements of cold must/wine
  • Fix leaking hoses and pumps to minimize O2 ingress
• Fine juice, settle and remove off lees quickly
  • Clarification enzymes to aid in cleaning juice (Lafazym CL and Endozym Muscat are both amazing and rapid)
  • Beta-glucanase enzymes effectively break down glucan chains (Extralyse at 1-3g/hL, Endozym Antibotrytis or Glucapec 2-4g/hL)

Oxidation prevention products are useful after enzyme treatments to prepare the juice for a healthy fermentation. Be aware that products containing bentonite will inactivate enzyme activity so should be added after any enzyme treatments are made.

• Combinations of PVPP, Casein, Bentonite, and Isinglass will effectively fine the juice to enable racking off the infected lees, prevent/treat oxidation, and remove unwanted proteins and laccase. (500-1000mg/L)
  • Polymust Press: PVPP, Vegetal Protein, Bentonite
  • Polylact: PVPP & Potassium Caseinate
  • Microcel: Potassium Caseinate, Bentonite, Cellulose
  • Casei Plus: Potassium, Bentonite
  • Catalasi AF Plus: Bentonite, PVPP, Silica gel, Isinglass

In addition, these products can also be used during fermentation to further extend oxidation protection

• Avoid indigenous fermentation
  • High populations of spoilage microorganisms are present in the infected fruit and juice
  • Fast and effective management of unwanted yeast and bacteria through SO2 additions and cold juice temperatures will minimize spoilage potential
  • Initiate Alcoholic fermentation quickly and provide nutrition
  • Select strains with short lag phase, minimal nutrient requirements, and moderate to fast fermentation kinetics
  • Higher inoculation rates (40-60g/HL) are shown to speed fermentation and compensate for the high SO2 concentrations
  • Mold infections tend to lower yeast available nutrients due to microbial metabolism
  • Ensure YAN’s are checked, and a combination of complex nutrients and DAP are utilised to ensure healthy and complete fermentation
    • Rehydration nutrients (Fermoplus Energy Glu, Superstart)
    • Complex nutrients (Integrateur, Nutristart)
    • DAP (Thiazote, Enovit)
• Remove wine from lees immediately after alcoholic fermentation has finished
• Perform tests for glucans post fermentation prior to filtration
  • If glucans are present, beta glucan enzymes can be added to degrade rot derived glucans and decrease clogging index prior to filtration (Extralyse at 1-3g/hL, Endozym Antibotrytis or Glucapec 2-4g/hL)

White Grapes

Same concepts as white winemaking with red wine specific suggestions below.

• Keep pre-fermentation stage as short at possible
  • Cold soak will allow increased spoilage microorganism populations
  • Shorter pre-fermentation stage will limit air contact/oxygen pick up
• Sacrificial tannin additions 200-500mg/L
  • Tannin VR Supra or Fermotan used at the crusher or immediately after to inhibit oxidation enzymes and bind proteins derived from spoilage microorganisms
• Extraction enzymes during early fermentation, beta-glucanase at mid fermentation
  • Short maceration times are recommended to limit laccase and polyphenol oxidase effects
  • Laccase can oxidize anthocyanins making colour stability an issue in reds
  • Extracting as much from the skins during fermentation will increase colour intensity and stability (LafazymFruit or Endozym Pellicular)
• Assess cap management techniques
  • Limiting pump overs/punch downs will reduce oxygen introduction and mechanical break down of mouldy skins
• Avoid removing lees from tank when digging out/pressing off
  • Glucans and unwanted enzymes/proteins will settle in the lees and should not be reintroduced into the wine
• Press while CO2 is still actively being producedoCO2 will limit ingress of O2 into wine
  • Active yeast will scavenge any oxygen that is dissolved and limit the oxygen available for laccase spoilage
  • Fine heavy pressings with beta glucanase enzymes (Extralyse at 1-3g/hL, Endozym Antibotrytis 2-4g/h
• Drain to tank not barrel
  • Drain/pump red wine to tank and allow lees to settle prior to barrel filling
  • Further racking can limit laccase activity by reducing contaminated lees
  • Test for laccase activity prior to going to barrel and treat with Tannins or Endozym Antibotrytis if laccase is present
• Beta glucan enzyme treatment can aid in filtration/clarification
  • (Extralyse at 1-3g/hL, Endozym Antibotrytis or Glucapec 2-4g/hL)

These are guidelines only and to be applied based on the extent of infection and condition of fruit. All necessary viticultural prevention should be taken to prevent/minimize fungal infection.

Trials are always recommended when assessing dosage rates and product impacts on juice and wine.

Contact your local representative for product information and availability.

Andy Shillington • [email protected] • 1-250-878-595