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Juice Analyses

Note: New York Wine & Grape Foundation is able to subsidize the costs of analyses for New York bonded wineries and cideries that hold a winery license.  This subsidy will be based on your membership status with NYWGF, and your invoice will come directly from them.  The current member subsidy is 50% and non-member subsidy is 25%.

 

IR Juice Scan- Only for 100% grape juice 

  • Purpose: Snapshot of juice chemistry: brix, pH, titratable acidity, volatile acidity, alpha-amino nitrogen, ammonia, tartaric acid, and malic acid.
  • Technique: FTIR
    • Price- $30

Acidity: pH

  • Purpose: A measure of hydrogen ion concentration, pH affects microbial stability, concentration of molecular SO2, tartrate stability, and the perception of wine structure. 
  • Technique: pH meter
  • Analysis notes: Due to the buffering capacity of wine, pH is not always directly correlated with wine TA. Juice pH generally ranges from pH2.8 to pH4.
    • Price- $7.50

Acidity: Organic Acid Panel (tartaric, malic, acetic)

  • Purpose: A measure of the primary acids found in wine.
  • Technique: HPLC (tartaric, malic, lactic, acetic)
    • Price- $90
  • Technique: OenoFoss (FTIR) (100% grape juice only-malic, lactic, acetic)
    • Price- $30
  • Analysis notes: Malic and tartaric are the primary acids found in grape juice, with lesser amounts of citric acid.  Juice and wines produced from other fruits will be dominated by malic (apple) or citric (berries) acids.

Acidity: Titratable Acidity (TA)

  • Purpose: A measure of the acids in wine that can be neutralized with a base.
  • Technique: Autotitration (to pH 8.2) and pH meter
  • Analysis notes: Titratable acidity most closely corresponds to the sensory perception of acid strength; it should not to be confused with total acidity. Expressed in g/L tartaric acid equivalents.
    • Price- $15

Sugars: Soluble Solids (Brix)

  • Purpose: This measurement of the dissolved compounds in grape juice yields the approximate sugar concentration.
  • Technique: refractometry
    • Price- $7.50

Sulfur: Free and Total Sulfur Dioxide (SO2)

  • Purpose: Sulfur dioxide is used as an antimicrobial and antioxidant in wine production.
  • Technique: Foss FiaStar (segmented flow analysis)
  • Analysis notes: The legal limit is 350 mg/L, and concentrations above 10 mg/L (ppm) require the label to include the warning "contains sulfites." TTB CFR 4.22(b)(1)
    • Price- $35

Trace Elements: Copper, Potassium, Calcium, and Iron

  • Purpose: The concentration of dissolved analytes can affect wine stability. Excess calcium and potassium can promote tartrate precipitation, and copper and iron favor oxidation.
  • Technique: Atomic absorbance
  • Analysis notes: Turn around on this analysis is about one week.
    The amount of residual copper in wine cannot exceed 0.5 ppm.   TTB CFR 24.246
    • Price- $45 per element

Turbidity

  • Purpose: Turbidity is a measurement of juice clarity, which is reduced by the presence of suspended solids.
  • Technique: Nephlometer
  • Analysis notes: For sound grapes, a range of 100-250 NTU is generally considered optimum for a healthy fermentation.
    • Price- $15

Yeast Assimilable Nitrogen (YAN): Ammonia (NH3) and α-Amino Nitrogen (NOPA)

  • Purpose: Quantification of the total nitrogen available to yeast for fermentation.
  • Technique:  Enzymatic analysis
  • Analysis notes: Insufficient YAN can lead to slow or stuck fermentations and excessive hydrogen sulfide production.
    • Price- $55

Yeast Assimilable Nitrogen (YAN): α-Amino Nitrogen (NOPA) ONLY

  • Purpose: Quantification of the total nitrogen available to yeast for fermentation.
  • Technique:  Enzymatic analysis
  • Analysis notes: Apple juice generally has no ammonia, so only the α-Amino Nitrogen assay is required.
    • Price- $40

Consultation

  • Purpose: Troubleshooting or production planning beyond that related to service analyses
  • Analysis notes: Enology extension faculty and staff are available for consultation, but please note that we are not able to provide general product development assistance.
    • Price- $150/hr

* New York Wine & Grape Foundation is able to subsidize the costs of analyses for New York bonded wineries and cideries that hold a winery license.  This subsidy will be based on your membership status with NYWGF, and your invoice will come directly from them.  The current member subsidy is 50% and non-member subsidy is 25%.