What is pH? pH or “pouvoir Hydrogène” in French, means hydrogen power and is related to the real acidity of must or wine. This publication goes through the steps to measure pH levels in wine. pH measures the strength and the concentration of acids able to dissociate into protons (H+ ) and negative ions (A- ).
View PDFGrape sampling is a way of monitoring the progress in the vineyard. The question of whether it is time to pick can’t be answered by sampling once, but by looking at multiple factors as they change over time. Typical measurements include Total Soluble Solids (TSS) measured as °Brix, pH, and titratable acidity, and should be supplemented by sensory analysis.
View PDFAn accurate predictive model for estimating the timing of seasonal phenological stages of grape ( Vitis L.) would be a valuable tool for crop management. Currently the most used index for predicting the phenological timing of fruit crops is growing degree days (GDD), but the predictive accuracy of the GDD index varies from season-to-season and is considered unsatisfactory for grapevines grown in the midwestern United States.
View PDFLike most winery operations, the main goal of proper cleaning and sanitation is to promote wine quality, and to keep quality consistently high. Consistent quality, in turn, contributes to the winery’s positive reputation and promotes sales. Improper sanitation can lead to unwanted sensory characteristics from spoilage yeast and spoilage bacteria, as well as unwanted fermentations, which may cause fizziness, haze, pushing corks, and even shattered bottles.
View PDFRefermentation by Saccharomyces cerevisiae or spoilage yeasts occurs when there is available sugar in the wine and insufficient inhibition for the yeast. It can result in perceptible effervescence or fizz caused by carbon dioxide (CO2) in the wine, microbial or fermentative off aromas and flavors, a drop in residual sugar (RS), visible haze or sediment, pushing corks, or shattered bottles.
View PDFProtein instability or protein haze is a visual defect which is particularly noticeable in white wines. It can make the wine appear murky, cloudy, or turbid, or can even result in an unattractive precipitate at the bottom of the bottle.Protein stability is also sometimes called heat stability, because heating a wine can cause proteins to become unstable faster. To achieve protein stability in wines, various treatments and fining agents may be used.
View PDF