Histamines, found in the skins of grapes, seem to give some people headaches if they are sensitive to histamines. Red wine will affect a histamine sensitive wine drinker more than white wine because red wine has spent more time in contact with grape skins.

The calories in a 4 ounce glass of wine ranges from about 80 to 100 calories. Lighter wines tend to have fewer calories than heavier wines. Some wines are higher in carbohydrates than others due to their residual sugars. For example, a dry white wine may have 1 gram of carbohydrate where as a very sweet dessert wine could have up to 13 grams. Wine is fat free and contains no cholesterol.

A dessert wine is usually a sweet wine drunk at or for dessert. Due to its sweetness it is drunk in smaller quantities than table wine. In the U.S., the classification of dessert wine is that of wines which are fortified (the addition of brandy or other spirits to raise the level of alcohol in the wine) whether they are sweet or dry.

Although wines from different regions will vary in style, quality wines are produced all over the world. Each wine region may produce many types of wine, but most likely specialize and excel in a few due to weather and growing conditions.

White wines are generally made with grapes with yellow or green skins. White wines can also be made from black-skinned grapes if the juice is separated from the grape skins early enough i.e., before fermentation. Red wines get their color from being fermented in contact with the skins of dark grapes. Rosé gets its pink color by either a short contact time with the skins of dark-colored grapes before fermentation or by mixing finished red wine with finished white wine.

Cork is used to stop wine bottles because its structure renders it light, elastic, and impermeable to most liquids and gases. Corks are produced using the bark of cork trees grown in the western Mediterranean.

The characteristics of a particular vintage are determined by the quality of that years grape crop. Improvements in wine making over the years have made vintage year less central to choosing a wine produced in most wine regions. Vintages are more important when collecting more expensive wines, especially those designed to be aged, and in growing regions where a less than satisfactory growing season is not compensated for using innovative wine making technology or practices.

Sulfite is a term used to describe sulfur dioxide and other sulfur derivatives. Sulfites are found in all wines as they are a natural product of fermentation. Sulfur dioxide is used in wine making to prevent oxidation, kill bacteria and wild yeasts, and encourage quick and clean fermentation. The U.S. government requires wine labels to include Contains Sulfites to alert those who may be allergic to sulfites. Approximately 1% of the population is allergic to sulfites.

The vintage year on a wine label is the harvest year of the grapes from which the wine was made. The characteristics of a particular vintage year are determined by the weather conditions and resulting grape crop for that year. A California wine with a vintage date must be made from at least 95 percent of grapes harvested in the designated year.

The purpose of a wine rating is to quantify a wines quality separate from those factors that influence price. Rating systems vary. Some rating systems are based on a 50 to 100-point scale, others on a 5-point scale, etc. Keep in mind when looking at ratings, that the evaluation of wine is subjective. Factors like bottle variability, tasting conditions, and the judges likes and dislikes will influence a rating. You are the best judge of wine when it comes to what you enjoy drinking. Ratings can be used as a helpful guideline for choosing a wine once you are familiar with the raters preferred style (if an individual) or the preferred style of those judges whose opinions contribute to a rating.

The following is a synopsis of the basic steps taken to make wine:

Grapes are crushed to release the sugar in their juice. The juice naturally ferments when yeast comes in contact with the sugar in the grape juice. The result is alcohol and carbon dioxide.

Red wine is made with dark-skinned grapes and fermented with the grape skins. White wines are made with white grapes, or if made with some dark-skinned grapes the grape skins are removed prior to fermentation. Rosé wines have contact with the skins of dark-skinned grapes just long enough to impart a pink color.

The fermented wine is then separated from the grape solids and transferred into a vat or casks where it is clarified, stabilized, and may be taken though optional processes. Finally, the wine is bottled.

A wine is kosher if it is made using strict rabbinical production techniques. A kosher wine cannot include any chemical additives, gelatin, lactose, glycerin, corn products or nonwine yeasts. In addition, the entire wine making process must be conducted by Sabbath-observing Jews under rabbinical supervision. Kosher wines are produced by wineries all over the world.

A natural process during which beneficial bacteria convert the malic (very tart) acid in a wine to lactic (softer tasting) acid. Malolactic fermentation can take place on its own or be prompted by the winemaker.

Corks are produced from the bark of a tree grown in the western Mediterranean. It is unique in that it can be peeled from the tree without hurting the tree.

Botrytized wines are those that have become sweet, aromatic, and what is sometimes called "honeyed" due to grapes that have been infected with a mold known as botrytis cinerea.