Ernest and Julio Gallo learned how to make wine from a pamphlet they found in the local library, and they did all right.
Most wine is made from grapes, but it may also be made from other types of fruit.
The science of wine and winemaking is known as oenology.
The biggest factor that determines the quality of wine is the grapes, and grape quality is affected by variety as well as other factors including weather, soil minerals and acidity, time of harvest, and pruning method.
The most common species of wine grape is Vitis vinifera, which is what most wine from Europe is made from.