Glossary of Winemaking
Acidification (Tartaric Acid) is the process of adding tartaric acid (naturally occurring in grapes) to increase acidity. It is commonly done in warm regions, such as California, and also after amelioration to readjust acids due to the increased volume of liquid.
Alcohol in wine is primarily ethanol (EtOH) and is reported as %/vol. It is a critical constituent of wine and is produced from sugar during fermentation. The concentration of ethanol in wine can affect taste, microbial activity and the solubility of compounds
Amelioration (H2O), a widely used practice in California to reduce potential alcohol, is done by adding water to the must before fermentation. It is also used to reduced acidic musts when grapes are picked while acids are excessively high.
Botrytis cinerea is a fungus that affects many plant species, although most notably associated with wine grapes. In viticulture, it is commonly known as botrytis bunch rot or, when beneficial like in Sauternes, noble rot.
Diammonium Phosphate (DAP) is the basic nitrogen source added to fermenting wine as an essential yeast nutrient halfway through the primary fermentation.
Filtration (Rough Polish - 2.5µ) is employed to remove solid particles and improve the clarity of a wine. Filtration occurs when wine is pushed through a membrane where particles are trapped on the filter’s surface. Only rough filtration is used before bottling so not to reduce the complexity and character of the wine.
Malic Acid (MA) is one of the major organic acids found naturally in grapes, L-malic acid contributes sharp green flavors (sour apple) to wine. Malic acid concentration is an important component of the calculations necessary to make acid adjustments to must. This test is also useful for monitoring malolactic fermentation during which malic acid is converted enzymatically by lactic acid bacteria to lactic acid.
Microessentials Oenos (Malolactic Nutrients) is a complex nutrient formulated for growth and survival of malolactic bacteria. Bacteria cannot store, nor synthesize all essential amino acids, so complex nutrient supplements are necessary. Newly fermented wine can often be deficient or devoid of nutrients due to yeast utilization.
pH is the measure of a solution’s acidity, or hydrogen ion concentration. Solutions with low pH values (<7) are acidic, while those with high pH values (>7) are basic. Wine pH values typically fall between 3.0 and 4.0 on the pH scale. pH is a critical constituent of wine, affecting microbial activity, tartrate solubility, the interaction of phenolic compounds (color stability), and molecular SO2 levels.
Punch Down is a technique used to break up and re-submerge the cap (skins and seeds that rise and solidify) and control temperature during primary fermentation.
Sulfur Dioxide (SO2) is commonly used at key points during the winemaking process to prevent bacterial spoilage and oxidation. Additions of 2-8g potassium metabisulphite (K2S2O5) per hectoliter are added during destemming/crushing to achieve concentration levels 10 to 40 ppm in order to inhibit bacterial growth and prevent wild yeast strains from starting fermentation.
SO2 is also added just after malolactic fermentation and before bottling to maintain sufficient protection levels (25 to 30 parts per million) throughout the life of the wine. Without SO2, wines would typically oxidize and/or be attacked by microbes.
SuperFood (Yeast Nutrients) contains yeast hulls, inorganic nitrogen (DAP), yeast extracts, complex minerals and vitamins essential for healthy yeast population growth and metabolism.
Total Acidity (TA) in the U.S. is measured assuming that all acid is tartaric. Tartaric acid plays a prominent role in maintaining chemical stability and in influencing taste.
Volatile Acidity (VA), by its name and unlike Malic and Tartaric acid, is volatile and is represented by the presence if acetic acid. At low concentrations, VA can contribute to a wines aroma and taste. However, at high levels it can render a wine sour and vinegar-like.
Vinflora Oenos (Malolactic Bacteria) is a freeze-dried pure culture of Oenococcus oeni. It is has been carefully selected to induce malolactic fermentation after direct inoculation into the wine. It ensures a fast and safe malolactic fermentation.
Yeast (D254) was isolated by the ICV (Institute Coopératif du Vin) from a Syrah fermentation in the Rhone Valley. It was chosen for its ability to tolerate alcohol levels up to 16% of well aerated and cool (less than 82˚F) fermentations. it is also known to accentuate ripe fruit, cedar aromas and spiciness. It also contributes high fore-mouth volume, big mid-palate mouthfeel and intense fruit concentration.