Terminology used by
Acetic acid is formed if conditions exist for the formation of vinegar. There is no cure, just prevention, which is to have a proper TA (total acid) and
brix in the juice or TA and alcohol in the wine, the use of metabisulfite and the minimization of oxygen,
Amelioration is the addition of water.
Aroma: smell, odors.
Balling: brix with presence of some alcohol.
Brix, degrees brix: % of sugar in fresh grape juice.
Browning: oxidation, an undesirable brown, amber, dark yellow color change in wine resulting from
oxidation. Contributes to an off flavor and is more noticeable in
whites than reds. It can be a stepping stone to sherry and
Cap: grape solids that separate from the juice of crushed grape must.
They float and compact on the surface.
Chaptilization is the addition of sugar usually before fermentation.
Cold stabilization is the removal of excess potassium bitartrate, which prevents it from crystallizing on the cork
and/or precipitating in the bottle of finished wines stored under cold conditions. This process reduces acid in a finished wine.
Crusher is a machine for breaking grape berry skins to permit juice extraction.
Crusher de-stemmer breaks the skins and removes the stems.
De-acidification is the reduction of the TA (total acidity) in the juice, must or wine.
Dry is an absence of fermentable sugar. The finish taste is not
sweet. There may still be fermentable sugar present and the taste may
still be ‘dry’.
Ethanol, ethyl alcohol is a product of grape sugar fermentation.
Fermentation is the conversion of grape sugar by yeast to ethanol and carbon dioxide.
Fermentation trap or airlock is a device that allows the escape of carbon dioxide gas and prevents the entrance of
Fermenter is a vessel, bucket, pail, or carboy, used to conduct fermentation.
Fining agents are various materials that remove certain wine constituents for improved wine quality and clarity or
Free run is the juice that separated freely from grape solids without the use of mechanical pressure.
Free SO2 is the sulfur dioxide ions in a solution that are not chemically bound but are free or available to react
with such substances such as dissolved oxygen, etc.
Fructose is one of two simple fermentable sugars present in grapes.
Glucose is one of two simple fermentable sugars present in grapes.
Hydrometer is an instrument used for measuring dissolved solids such as sugar in grapes or wine.
Hot stabilization is fining for protein stability with use of Bentonite or LQ Superkleer or other fining agents. If
you are taking wine to Arizona or Florida, fine first.
Lactic acid is produced from malic acid by malolactic bacteria, such as in a malolactic fermentation.
Lees is the residue of wine fermentation that settles to the bottom of the fermenter during fermentation.
Malic acid is one of several organic acids present in grapes.
Malolactic fermentation is the conversion of malic acid in wine into lactic acid and carbon dioxide by lactic acid
Lactic acid is much softer on the palate and its presence gives wine an enhanced mouth feel.
It is a tradition finish for many reds and white wines.
Metabisulfite, potassium or sodium is a solid form of sulfur dioxide. It is an anti-bacterial and an anti-oxidant
agent widely used in winemaking (for centuries) at a rate of 40-50 ppm. When used in solution with citric acid, it
is a powerful cleaning agent.
CALCULATING SO2 ADDITIONS (POTASSIUM METABISULFITE) 576% (0.576) OF POTASSIUM METABISULFITE IS
Example: to add 50 ppm to 100 L
Desired addition (g/L)* volume (L)/0.576=grams of Meta to add
50 ppm = 50 mg/L = 0.050g/L
0.050*100 (liters)/0.576=8.6 grams of meta to add to 100L for 50ppm
100 Liters is 26.42 gallons
Must is a slurry of crushed grapes.
Oxidation is a process whereby grapes, juices or wine react with oxygen resulting in undesirable odor and taste and
pH denotes the hydrogen ion activity in an aqueous solution. There are safe and desirable parameters for wines and
Pomace is the remaining grape sins, seeds and pulp after pressing. It is usually spread back into the vineyard and
may be used for making a “second wine”.
Pressing uses pressure to extract the juice or wine from the grape must such as a wine press, basket press, bladder
Punching down is pushing the floating cap back into the juice to facilitate color and flavor extraction during
fermentation of the grape as must.
Racking is the transfer of clear juice or wine from the lees via siphoning.
Racking wand is a rigid, usually acrylic (clear) rod to aid in siphoning or racking.
Residual sugar (RS) is remaining un-fermented sugars in wine after fermentation. It may have a taste of sweetness
if the percentage is high enough.
Stemmer separates the grape stems from the berries.
Stuck fermentation is the premature cessation of fermentation and may be desired or un-desired.
Sulfur Dioxide (SO2) as metabisulfite, potassium or sodium is a solid form of sulfur dioxide. It is an
anti-bacterial and an anti-oxidant agent widely used in winemaking (for centuries). When used in solution with
citric acid, it is a powerful cleaning agent.
Tannins are a phenolic compound occurring naturally in grapes and wines giving astringency and or bitter flavors in
wine. Tannins are highly present in the stems, which is the reason for de-stemming. We like to leave about 10% of
Tartaric acid is the principal organic acid of most grapes.
Thief is a straw like tool to steal some wine for a
sample. Some are glass straws and the plastic. Fermtech wine thief can double as a hydrometer jar.
Titratable acidity is the concentration of organic acids in juice or wine determined by titration acid test using
sodium hydroxide. The acid is expressed as total acid (TA) as grams tartaric acid per liter. There are desired
parameters for initial and finish TA in winemaking.
Topping up is the process of keeping carboys of wine filled to the top or desired level by the addition of
Total SO2 is the total of free SO2 and bound or combined SO2.
Remember there is always more than meets the eye.