The location (what country the wine is being made in) obviously plays a key role, as does the location of the vines themselves (are they grown on high ground or low, facing the sun or not).

Other factors include the climate, the local weather during the growing season, the soil type, whether the vineyard is using local wine making customs or modern methods and, of course, the skill of the winemaker himself. But, most important is the wine variety.

Each month, Mary and Barry Sapsford will be taking a look at a popular wine variety. They will touch on the different flavours the same variety can offer depending on its country of origin and will also suggest what foods go best with each one.

THIS MONTH - SAUVIGNON BLANC.

Sauvignon Blanc is now made in most wine producing parts of the globe, but is thought to have originated from France's Bordeaux region.

It is just the job for summer drinking - a dry, zingy, refreshing white wine with its own definite character.

Pour a glass and hold it against a white surface or a piece of paper and you'll find it is a very light straw colour. Take a sniff and you will begin to get to know the character of Sauvignon Blanc. What does it remind you of? Gooseberries, grass, blackcurrant leaves?

Now taste it. A medium bodied white wine whose main charm is its cool, dry lightness and freshness. What better for an aperitif on a warm Summer evening?

Perhaps the best known Sauvignon Blanc wines are Sancerre and Pouilly Fumé from the sedimentary soils of the Loire Valley in France. Close by are the areas of Quincy, Menetou Salon and Reuilly, which all produce very similar wines. These are all very dry and possess an almost flinty quality - very appealing.

To the south west, the more gravelly soils of Bordeaux also suit this grape, but it is blended with Semillon and occasionally other varieties to product dry white Bordeaux wines.

Because of the blending, some of the Sauvignon Blanc characteristics are rounded and softened and the product is perhaps less austere than in the Loire Valley.

Also, in this region the grapes are picked very late, when they are full of sugar and again blended with Semillon to produce the a sweet, dessert wine Sauterne. There are other dessert wines nearby using this combination of grape types.