Glossary of Winemaking Terms - P

P

Pad filitration

A technique of filtering wine that involves running the wine through a series of pads made of asbestos, cellulose or thin paper sheet.

Passito

A method of straw wine production that involves drying bunches of grapes in a special room in order to dehydrate them and concentrate flavors. In some circumstances the grapes maybe left on the vine to dry out in a method similar to the French technique of passerillage.

Pasteurization

An umbrella term for various methods of sterilization and stabilization of the grape must.

Pectic enzyme

An enzyme added to fruit to increase juice yield. Also used as a clarifying agent in fruit wines when added to wine or must to eliminate pectin hazes.

Perlant

French term for a very lightly sparkling wine with less effervescence than a crémant or pétillant

Perlite

A fine, powder-like substance of volcanic origins that is sometimes used for ceramic filtration. It has many of the same filtering properties as diatomaceous earth.

pH

A measure of the acidity. The lower the pH, the higher the acidity. The term comes from the French Pouvoir Hydrogéne meaning "hydrogen power". pH is a shorthand for its mathematical approximation: in chemistry a small p is used in place of writing log10 and the H here represents, the concentration of hydrogen ions.

Phenolic compounds

Compounds found in the seeds, skins and stalks of grapes that contribute vital characteristics to the color, texture and flavor of wine. Two of the most notable phenols in wine include anthocyanins which impart color and tannins which add texture and aging potential.

Pipe

A Portuguese oak barrel with the capacity of 145 gallons (550 liters).

Polishing

An ultrafine means of filtration usually done with kieselguhr or perlite that leaves a wine with exceptionally bright clarity – giving the impression that it has been polished. Premium wines will often decline polishing because ultra fine precision can also remove flavor and phenolic compounds that may diminish the quality and aging potential of the wine.

Pneumatage

A relatively new word, coined in 1999 by American winemaker Berle W Figgins, Jr, applied to a method of cap management involving the use of dried and sterile-filtered compressed air to completely submerge the buoyant cap of solids in red wine musts. In contrast to pigeage and remontage, pneumatage employs sequential pulses of pneumatic energy to effect a zero-shear condition in homogenising red musts, resulting in minimised tannin extraction in tandem with enhanced colour extraction and optimised respiration during fermentation. Pneumatage is a registered trade name for the winemaking application of the mixing technology developed by Pulsair Systems of Bellevue, Washington, USA. As the technology becomes adopted, pneumatage is in increased usage as a generic term for the action of pneumatically submerging the buoyant cap of solids in red winemaking.

Polyvinylpolypyrrolidone

A fining agent, more commonly abbreviated as PVPP, used in white wine production to remove compounds that can contribute to premature browning of the wine.

Pomace

The skins, stalks, and pips (seeds) that remain after making wine. Also called marc.

Post-disgorgement aging

The time a sparkling wine spend aging in the bottle between when it has been disgorged to when the bottle is opened for consumption.

Potassium sorbate

A wine stabilizer and preservative.

Pre-fermentation maceration

The time prior to fermentation that the grape must spends in contact with it skins. This technique may enhance some of the varietal characteristics of the wine and leech important phenolic compounds out from the skin. This process can be done either cold (also known as a "cold soak") or at warmer temperatures.

Proof

Refers to the alcohol content of a beverage. In the United States, proof represents twice the alcohol content as a percentage of volume. Thus, a 100 proof beverage is 50% alcohol by volume and a 150 proof beverage is 75% alcohol. In the Imperial system, proof, (or 100% proof), equals 57.06% ethanol by volume, or 48.24% by weight. Absolute or pure ethanol is 75.25 over proof, or 175.25 proof.

Protein haze

A condition in wines with an excessive amount of protein particles. These particles react with tannins to create a cloudy, hazy appearance in the wine. This condition is rectify with the use of a fining agent, such as bentonite, to remove the proteins.

Puncheon

An oak wine barrel with the capacity of 119 gallons (450 liters)

Pyrazines

A group of aromatic compounds in grapes that contribute to some of the green herbaceous notes in wine from the green bell pepper notes in some Cabernet Sauvignon to the grassy notes of some Sauvignon blanc. In red wines, the abundance of pyrazines can be a sign that the grapes came from vines with vigorous leaf canopy that impeded the ripening process of the grapes.