A wine grape named Monica

I'm researching wine grape varieties. I'm trying to discover a) how many varieties of grapes are used to make wine in the world today and b) how many and which varieties make up 80% of the wine produced in the world. I'm doing this so I can focus my wine tasting and learning on the top wines, at least to start with.

Using the trusty internet as my research vehicle, I have found that between 600 and over 10,000 varieties of wine grapes exist. I'm going to ball park the figure at about 1,000 because this is the rough count of an actual list I found at something fairly official looking from UC Davis.

In reviewing the various wine grape lists, I couldn't help but notice 1 grape's name: Monica. This is what Wikipedia has to say about the Monica Grape: Monica is a red wine grape that is grown primarily in Sardinia and is one of the few grapes that wine regulations allow to appear on the wine label. The vine originated in Spain but is rarely grown there in recent times. The wine made from these grapes tends to be simple wines made to be consumed young.

Monica di Cagliari is a notable sweet wine made from the grape. Monica di Sardegna is a drier wine.

I'm having difficulty finding a statistic out there listing the $ or gallons of wine consumed today by wine grape, but I'm guessing based on what I read that 80% of the wines produced today are from these most popular wine grapes: Whites -- Riesling, Sauvignon Blanc, Chardonnay, Pinot Gris/Pinot Grigio and Reds -- Cabernet Sauvingnon, Merlot, Pinot Noir, Zinfandel and Syrah/Shiraz.

To start with, we'll try to understand these 8 grapes and the types of wine they make. Then, we can move on to some other types of wines... using these as a springboard. It seems to make sense given that my goal is to try to simplify the process of learning about wines that we should focus on these grapes first!