Last night, I did a bit of consulting for a couple that is having a wedding in October. I showed them a number of different wines at a couple of different price points. As I was doing this, it occured to me that many people can get overwhelmed when planning a party, especially when it comes to the quantity and types of wines to pour. Let me offer just a few tips.
First of all, it's important to figure out how much wine you need to buy. A typical 750 ml bottle of wine has 25.4 oz of liquid. This means that there are about 4 glasses of wine per bottle. If you are thinking in terms of 12-bottle cases, then there are roughly 50 glasses of wine per case. I would suggest buying case-loads, since many retailers will give you a price break if you buy a case or more. Now you have to consider your audience. Are they light or heavy drinkers? Do they mostly drink wine? Will you also be offering beer or liquor? For a "normal" crowd, you can plan on about 2-3 glasses of wine per person. Some groups will drink a lot more, others will drink a lot less, you will have to make the call.
Next, think about the selection. My suggestion for a big party is to have a breakdown of about 10% bubbly wine (especially if you are going to do a toast, there are about 6-8 servings of bubbly in a glass for toasting purposes), 40% white wine, and 50% red wine. When it comes to the types of white wine, don't go too crazy- I would do mainly "crowd pleasers", with a couple of other bottles thrown in for picky people. If you do about half chardonnay, and half pinot grigio, with a couple bottles of riesling thrown in, you will cover most everybody's likes. This also is the same for the reds- go with easy to drink varietals (cab, shiraz, malbec, pinot noir), with a couple bottles of something off the path (spain, bordeaux) for the wine geeks. Trust me, unless you have a crowd of all sommeliers or wine reps, it doesn't matter what you throw out there- people will drink it. I almost always have inexpensive bubbly, and a case of cheap (like around $10) white and red at the house, just for people to drink. If you get something from Italy or Spain, people have no idea what you paid for it, and automatically think it's good.
This leads to my last points- don't spend more than you have to. Most people don't care if it's a $40 syrah that scored 94 points from Parker. They see it as red wine, and it tastes good. That's okay. A large party isn't necessarily the time to teach people everything you know about wine. Instead, just pour them something inexpensive that they will quaff, and have a good time. I usually open something good for myself, and people "in the know", and hide it. Oh, one other thing...don't let people just start pulling stuff out of your rack and opening it. That's a great way to have someone crack open a bottle you were saving for later. I literally keep all of my "trophy" bottles at my office. This way, I have to consciously think about bringing it home to drink, since I'm not going to leave my house and make an hour round trip to grab a bottle while I'm throwing a party. It also keeps us from opening something special at the end of the night, when nobody will be able to taste it anyway.
Today's wine suggestion is a perfect example of a good party wine- try the Bodegas Olivares "Altos de la Hoya". This is a 100% monastrell from Jumilla, Spain. It has a good balance of plum and blackberry fruit, along with old-world rusticity and charm. It should cost you roughly $11 retail.