Harvest Information for Wine Grapes

Before you pick any grapes:  Wine grapes should be between 21-24 brix optimally, pH 3.5-3.7 for red grapes or 3.2-3.4 for white grapes or rosé style reds.  Birds and other critters will start eating your grapes at least 2-3 weeks before you should harvest!  Invest in some good netting, bee netting is preferred.  Just because your grapes turned red does NOT mean they are ready to harvest – sugar and acid levels are optimal around 6-8 weeks after color change (veraison) starts.

Red Wine Making checklist for processing 100 pounds of grapes

  • Grapes should be at brix 21-24, pH 3.5-3.7 for red grapes or 3.2-3.4 for white grapes or rosé style reds
    Day 1:
  • Crush and destem grapes from 100 lbs grapes
  • Add 1/4 tsp Potassium metabisulfite (KMS) to must
  • Check brix/SG; TA and/or pH: take out sample, pulse in food processor, strain out solids before testing
  • Add pectin enzyme or Lallzyme EX-V (one or the other), and Opti-Red (in addition, optional)
  • Let sit overnight with dry ice – 5 pounds per 100 pounds of grapes or frozen jug(s) of water to keep cold, ~50-60° F
    Day 2:
  • Activate 5 grams yeast in 50 mls of warm (104° F) filtered water for 15 – 30 minutes with 6.25 g Go-Ferm Protect
  • Add ½ cup grape juice and stir; let sit for 10 minutes
  • Stir into must
    Day 3:
  • Check brix
  • Punch down cap 2-3 times
  • Option 1 for malolactic fermentation (MLF): add malolactic bacteria (MLB) [coinoculation; option 2 is to add after
    fermentation finished and wine pressed, see below]; no additional nutrients necessary if adding MLB now
    Day 4:
  • Check brix
  • Punch down cap 2-3 times
    Day 5:
  • Check brix; if brix down 2/3 from start (~10 brix), add Fermaid K
  • Punch down cap 2-3 times
    → continue until brix = 0. Keep must covered with plastic wrap and purge airspace on top with CO2 if available until
    ready to press
    Press Wine
  • Can press wine if 5 brix or less, fermentation will finish in carboy after pressing; add rice hulls to improve yield or if
    volume not enough to fill press
  • Press into buckets or Brute food grade cans, cover top with plastic wrap directly on top of wine; let settle overnight
    Day after press:
  • Rack into a clean carboy, off of gross lees; if coinoculated MLF, test malic acid levels now
  • Top carboy close to base of neck, but leave some space for volume expansion and stirring with paddle during MLF
  • *Option 2 MLF (if did not coinoculate):
    o Rehydrate malolactic bacteria (MLB) if powdered form; not required for White Labs MLB
    o Rehydrate Opti-malo plus nutrient separately
    o Stir in
  • Stir gently once a week to encourage MLF
    → after ~3 weeks of MLF check lactic and malic acid levels
    MLF is complete when malic acid is gone – using quick tests, color will be white, not purple
    Continue stirring every week until MLF is complete
    → when MLF is complete, check pH and/or TA, and free SO2 levels and taste; adjust variables as necessary to taste
  • Rack into another clean carboy
  • Adjust SO2 to 30-50 ppm
  • Add oak if desired
    → Test, taste, and rack wine every 6 – 8 weeks
  • Test: free SO2; TA and/or pH
  • Add ¼ tsp KMS per 5-6 gallons wine at each rack to keep free SO2 25-50 ppm
  • If adjusting acids, do bench trials with small samples and taste first before adjusting entire batch
  • Rack off of oak after desired oak flavor is achieved
    → After 6-12 months, prepare to bottle
  • Check if fining/clarifying agents need to be added from clarity, taste
  • Adjust final pH and/or TA to taste
  • Adjust SO2 for bottling 30-50 ppm

White Wine Making checklist for processing 100 pounds of grapes
Day 1:

  • Crush and destem grapes then press, or press whole clusters; bladder press 25-30 psi, will need to press twice; add
    rice hulls to improve yield or if volume not enough to fill press
  • Add 1/4 tsp Potassium metabisulfite (KMS) and dissolve in small volume water; stir into must
  • Check brix/SG, TA and/or pH
  • Add pectin enzyme or Lallzyme EX-V (one or the other), and Opti-White (in addition, optional)
  • Let sit overnight with dry ice (~5 lbs per 6 gallons) or frozen jug(s) of water to keep cold, around 55-70° F to settle out
    Day 2:
  • Siphon or pump clear juice off of gross lees into fresh container for fermentation
  • Activate 5 grams yeast in 50 mls of warm (104° F) filtered water for 15 – 30 minutes with 6.25 g Go-Ferm Protect
  • Add ½ cup grape juice and stir; let sit for 10 minutes
  • Stir into juice
    Day 3: * Option 1 for malolactic fermentation (MLF): add malolactic bacteria [coinoculation; option 2 is to add after
    fermentation finished and wine pressed, see below]; no additional nutrients necessary if adding now – MLF is optional for
    white wines, not typically done
    → check brix daily until brix = 0
  • Rack again into a clean carboy, off of fine lees; if coinoculated MLF, test malic acid levels now
  • Top carboy close to base of neck, but leave some space for volume expansion and stirring with paddle if doing MLF
  • *Malolactic fermentation (MLF) option 2 (if did not coinoculate) – MLF is optional for white wines, not typically done:
    o Rehydrate malolactic bacteria (MLB) if powdered form; not required for White Labs MLB
    o Rehydrate Opti-malo plus nutrient separately
    o Stir in
  • Stir gently once a week to encourage MLF
    → after ~3 weeks of MLF check lactic and malic acid levels
    MLF is complete when malic acid is gone– using quick tests, color will be white, not purple
    Continue stirring every week until MLF is complete
    → when MLF is complete or if not doing MLF, add ¼ tsp potassium metabisulfite (KMS), check pH and/or TA and
    taste; adjust all variables as necessary.
    → Clarify wine: add 2 tsp bentonite directly to wine and leave in 2-6 weeks, rack off when wine mostly if not
    completely clear.
    Add oak if desired for 6-8 weeks. Rack off of oak after desired oak flavor is achieved.
    → Cold stabilize wine: Hold wine as close to freezing as possible (32° F; 40° F acceptable) for at least 2 weeks to
    encourage precipitation of tartrate crystals.
    → Test, taste, and rack wine every 6 – 8 weeks
  • Test: free SO2; TA and/or pH
  • Add ¼ tsp KMS per 5-6 gallons wine at each rack to keep free SO2 25-50 ppm
  • If adjusting acids, do bench trials with small samples and taste first before adjusting entire batch
    → After 4-6 months, prepare to bottle
  • Check if additional fining/clarifying agents need to be added from clarity, taste
  • Adjust final pH and/or TA to taste
  • Adjust SO2 for bottling