What is the  relationship between fruit color and wine color concentration? A strong, positive relationship exists between  anthocyanin (i.e. color)  concentration in grape and in wine (source). However, all anthocyanins accumulated in the skin are not completely extracted into the wine. For that reason, even if a relationship exists, the total amount of anthocyanins  extracted […]

In this blog we discuss why adapting harvest date to a warming environment is challenging …and why you may not have to trade off sugar concentration to get high color concentration. Higher sugar concentrations at harvest are often associated with an increase in temperature. This is observed empirically and scientifically in the […]

The Cool Night Index The Cool Night Index was created to study nocturnal conditions of grapes ripening according to the different wine-making regions (Tonietto, 1999 ; Tonietto et Carbonneau, 2004). By convention, this index is also called nycthermal index and is equivalent in the North Hemisphere to the minimum temperature […]

This discussion is a follow up with our last blog on the 2017 maturation What is the situation end of september? A general disorder in sugar accumulation is observed in northern California. The trend is widespread and shows sluggish sugar accumulation rate across many different vineyards. The extend of the phenomenon indicates […]

Harvest decision 2017: A ripe Cabernet Sauvignon in Napa “should be worth the wait!” We discuss a preliminary analysis of the 2017 vintage effect on berry ripening dynamics. Our main conclusions are synthesized in this short summary below. If you are interested in the rationales and discussion points, please scroll down after the […]

One of the main challenges for a winegrower before harvest is : “where is it best to sample?” and “how many locations do I need to sample to get a reliable estimate?” In this blog we discuss how to design a sampling scheme to best capture vineyard spatial variability. The plant […]

Phenolics within the grape play an important role in a wine’s sensorial properties, such as color, astringency, mouthfeel, and bitterness. For example, increasing the size of tannin molecules will increase astringency, or a higher level of epicatechin-3-O-gallate (ECG) will lead to more chalky dryness and a lower coarseness.  Thus, vineyard […]