Recently, we asked our friend, Chaad Thomas, the Wine Director at Paesano's, how to estimate the quantities of wine needed for an event, say a wedding. Chaad responded with the extremely helpful info below, and was kind enough to let us pass it along on the site.

As far as forecasting wine consumption for a wedding goes, there are a few basic precepts that I should mention. First is that a wedding is an important party, and that folks go to them to have a good time, so drinking is in order, unless there are known teatotalers in attendance. So basically, plan on heavy consumption and get more than you think you'll need, because you don't want to run out, particularly in a place where you can't make a quick dash to the store if needed.

That said, you can either estimate in terms of glasses or volume (i.e. ounces). I prefer ounces, because there is an amount between one glass and two glasses, and ounces express that most accurately.

The first part of the equation is determining whether or not other drinks will be offered, and whether or not wine will be offered for the entire event or only with, say, the main course. If wine is available from the get-go, folks will drink more. If it is offered in conjunction with beer and mixed drinks, they'll drink less than if wine were offered alone.

Remember that some folks will drink heavily, some not at all, most moderately.

So, numbers-wise, let's assume that you've got a passel of bon-vivants on the way for the festivities, that wine will be offered for the entire reception, and that a full bar is also available. For the purposes of the example, assume that 6oz = 1 glass of wine, 25oz = 1 750ml bottle, and there are 70 guests.

I'd calculate that everyone will drink at least 15oz (or, 2.5 glasses) in total. In order to meet that need, you'd want 42 bottles of wine (70 guests x 15oz / 25oz).

Since you'll probably serve both red and white, the 42 bottles will need to be split between the two, keeping in mind that a) most people drink red wine, and b) white wine drinkers tend to drink less. So I'd do a 60/40 red-to-white split in the summer, 70/30 in the winter, because I do see some seasonal drink habit shifts. I'd say that something like 2 cases (24 btls) of red and 1.5 cases of white (18 bottles) would serve 70 people without problem.

I hope the above info helps; the only major considerations are the number of guests and whether there's an open bar, in the absence of which I'd only move the per person ounces up to 18 (three glasses). If I had a case of Bruno Giacosa Barolo, I'd bet that either of these two valuations will result in having more wine that necessary, but again, you don't want to run out.