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HOW TO MANAGE PH AND ACID AFTER HEAT WAVE

Due to the recent heat wave, many of our clients have reported an unusual acid profile in grapes, juice and must characterized by high levels of malic acid associated with low levels of tartaric acid.

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Due to the recent heat wave, many of our clients have reported an unusual acid profile in grapes, juice and must characterized by high levels of malic acid associated with low levels of tartaric acid.
This unusual situation makes pH and Acid Management more difficult, as the traditional formulas for the calculation for acid and pH adjustments cannot be used.

Why is it Important to Manage Acid and pH?
Impacting mouthfeel, microbial stability, oxidative stability and efficiency of most of winemaking treatments, acid and pH management is a key factor in winemaking.                                              

Why do Acid Additions at Juice Stages?
Pre-fermentation acid additions are perceived as better integrated, while post-fermentation acid additions are sometimes perceived as being “hot” and not as harmonious. Pre-fermentation acid additions also lower the pH of juice/must helping to control spontaneous bacterial growth that can result in serious spoilage. It is suggested that lower pH’s in the must phase can lead to larger proportions of stable, polymeric color.

How to Decide the Acid Addition Rate
Winemakers have often relied on formulas and history with particular vineyards for acid addition rates. Due to juices’ unique buffering capacity, each juice’s pH will be affected differently due to changes in acid concentrations throughout fermentation. Vinquiry Laboratories by Enartis USA offers a systematic and scientifically predictive test to perform “on target” acid and pH adjustments at juice stage.

What Services does Vinquiry Laboratories offer to Help Manage pH and Acidity?

  • Juice Panel provides a complete snapshot of fruit maturity, fruit quality, acid balance and yeast nutritional needs. Panel includes °Brix by refractometer, ammonia, assimilable amino nitrogen, YAN calculation, pH, titratable acidity, potassium, organic acid profile and gluconic acid.
  • Organic Acid Profile (includes the four major wine acids): Malic Acid levels give a baseline for malolactic (ML) fermentation, Lactic Acid indicates the status of ML fermentation, Acetic Acid indicates the presence of spoilage, and Tartaric Acid is the main component that contributes to TA.
  • Potassium levels impact juice and wine pH, juice/wine buffer capacity and wine stability (microbial and colloidal).
  • Buffer Capacity plays a key role in acid additions by measuring the resistance of juice to changes in pH.
  • Predictive Guide for Acid Adjustment in Juice: To help winemakers take the guesswork out of pre-fermentation acid additions, Vinquiry Laboratories offer a Predictive Guide for Acid Adjustment in Juice which evaluates the impact of acid additions on the final pH of wines post malolactic fermentation (MLF). pH, TA (titratable acidity) and °Brix are needed to perform this panel. Panel includes organic acid profile, potassium, juice buffer capacity, initial pH and TA of the juice, predictive pHs and TAs after alcoholic and malolactic fermentation with various amount of tartaric acid additions, and juice/must pH and TA after tartaric acid addition.

For more information, please call (707) 838-6312.

 
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