Juice Analyses

Express Juice Chemistry Panel

  • Purpose: Snapshot of juice chemistry: brix, pH, titratable acidity, volatile acidity, alpha-amino nitrogen, ammonia, tartaric acid, malic acid, and gluconic acid.
  • Technique: FTIR
  • Price- NY*: $30;  Non NY: $70

Advanced Juice Chemistry Panel

  • Purpose: In depth juice chemistry: brix, pH, titratable acidity, volatile acidity, alpha-amino nitrogen, ammonia, tartaric acid, malic acid, gluconic acid, and yeast assimilable nitrogen (YAN, enzymatic analysis).
  • Technique: HPLC, FTIR, Enzymatic Analysis
  • Price- NY*: $65;  Non NY: $200

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- NY*: No charge; Price- non NY: $10

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

  • Purpose: A measure of the primary acids found in wine.
  • Technique: Foss OenoFoss (FTIR)
    • Price- NY*: $20; Price- non NY: $30
  • Technique: HPLC 
    • Price- NY*: $35; Price- non NY: $55
  • 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- NY*: $12; Price- non NY: $20

Consultation

  • Purpose: Troubleshooting or production planning beyond that related to service analyses
  • Analysis notes: Enology extension faculty and staff are available for consultation.
  • Price- NY*: No charge; Price- non NY: $150/hr

Sugars: Soluble Solids (Brix)

  • Purpose: This measurement of the dissolved compounds in grape juice yields the approximate sugar concentration.
  • Technique: refractometry
  • Price- NY*: No charge; Price- non NY: $10

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- NY*: $20; Price- non NY: $30

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- NY*: $25 per element; Non NY: $40 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- NY*: $15; Price- non NY: $25

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.  Note: Outside harvest season (late August-early November), minimum of 5 samples required.
  • Price- NY*: $35; Price- non NY: $55

 

* Analyses are offered at a discount to all New York bonded wineries, home winemakers, and craft distilleries because a portion of testing costs (approximately 33%) are subsidized by the New York Wine and Grape Foundation (NYWGF). We are unable to offer this discount to wine distributors or out-of-state wineries because of the nature of NYWGF funding.