Tuesday, May 02, 2006
A salt of potassium and tartaric acid which can precipitate out of a wine as crystals under chilled conditions.
One of two compounds which may be used to sanitize winemaking equipment and utensiles (the other being sodium metabisulfite). Potassium metabisulfite is the active ingredient in Campden tablets. Its action, in water, inhibits harmful bacteria through the release of sulfur dioxide, a powerful antiseptic. It can be used for sanitizing equipment and the must from which wine is to be made. For equipment, a 1% solution (10 grams disolved in 1 liter of water) is sufficient for washing and rinsing. After using the solution, the equipment should not again be rinsed. For sanitizing the must, a 10% solution is made (100 grams dissolved in 1 liter of water). Three milliliters of this 10% solution added to a U.S. gallon of must will add approximately 45 ppm of sulfur dioxide (SO2) to the must. One should wait at least 12 hours after sanitizing the must before adding the yeast. Both bottles of solution (1% and 10%) should be clearly labled as to strength and active compound to prevent disasterous mistakes, and both may be stored in a cool place for up to one year without effecting potency.
Also known as "Sorbistat K" and affectionately as "wine stabilizer," potassium sorbate produces sorbic acid when added to wine. It serves two purposes. When active fermentation has ceased and the wine racked the final time after clearing, 1/2 tsp. added to 1 gallon of wine will render any surviving yeast incapable of multiplying. Yeast living at that moment can continue fermenting any residual sugar into CO2 and alcohol, but when they die no new yeast will be present to cause future fermentation. When a wine is sweetened before bottling potassium sorbate is used to prevent refermentation. It should always be used in conjunction with potassium metabisulfite (1/4 teaspoon per 5 gallons of wine or 1 crushed and dissolved Campden tablet per gallon) and the wine will not be stabilized without it. It is primarily used with sweet wines and sparkling wines, but may be added to table wines which exhibit difficulty in maintaining clarity after fining.
The potential amount of alcohol that can be expected from a given must based on its measured specific gravity. See Brix and Specific Gravity.
To use pressure to force juice out of fruit pulp, or a device used to achieve this result.
Source: Jack Keller