Figuring out quantities for a large group can seem overwhelming, but a few calculations will simplify the task. Start by estimating the individual portion sizes in ounces, based on the demographics of your group. For example, if you're feeding kids, you probably need less than 4 ounces of meat per serving, or 1/4 pound. If you're feeding a bunch of linebackers, you might need to triple that amount. Most groups fall somewhere in between these two extremes. Once you've figured out individual serving sizes, multiply that amount by 50 to get a fairly accurate idea of how much you'll need. Remember, though, that it's always better to have a bit too much food than not enough, so err on the side of generous portions.
In general, you'll need between 1/3 and 1/2 pound of meat for each guest, or 15 to 25 pounds of meat. Hamburgers, hot dogs and brats are the simplest to calculate because these meats come pre-counted and packaged. Buy enough for each person to have one, plus an additional 20 to 30 percent for seconds. If you're making pulled pork sandwiches, plan on between 15 and 20 pounds of pork. The pork stretches farther because it's shredded, but if it contains a lot of fat, it will shrink during cooking. If you're doing chicken breasts, plan on 25 pounds, or one breast per person.
When it comes to planning side dishes, plan on about 6 ounces total per person, which comes to 300 ounces for a group of 50. This breaks downs to almost 3 gallons or just under 20 pounds of food. An ideal configuration would be 1 gallon of potato or pasta salad, 1 gallon of fruit salad and 1 gallon of lettuce salad. Add 1 ounce of potato chips per person, or 50 ounces total, and you should have plenty of food.
Don't forget the drinks, especially if it's a hot day. You'll need about 32 ounces of lemonade, water or soda for each guest, or 1,600 ounces total. If the barbecue's an informal affair, fill one large cooler with lemonade or soft drinks and one with water, and you'll have enough to drink. You can also fill large buckets with ice and buy individual bottles and cans of soda, juice and water. If you opt to go this route, you'll need at least 30 bottles of water and 50 cans of soda. If you're serving beer, plan on one or two per person. Again, estimate more or less based on what you know about your guests' drinking habits. Pick up at least 35 to 40 pounds of ice to cool the drinks and keep food chilled.
Figuring out the toppings trays can be tricky. If you're making hamburgers, plan on at least five onions, three heads of lettuce and 10 tomatoes for the condiment trays. You'll probably need 1 1/2 pounds of sliced cheese, as well as 1 to 2 quarts each of salad dressing, ketchup and mustard.
A party's not a party without dessert. Brownies, cookies and cookie bars are probably the simplest dessert for a barbecue, because you can portion them out ahead of time. Plan on 75 to 100 cookies or bars. You'll need at least two gallons of ice cream, or two large sheet cakes.
One of the most challenging aspects of hosting a barbecue is keeping the food safe. Refrigerate cold foods until immediately before serving at 40 degrees Fahrenheit, and serve these foods on ice, if possible. Use chafing dishes and steam tables to keep hot foods at at least 140 F. If the weather's hot, the food should probably be discarded at the end of the barbecue because hot temperatures increase the likelihood of bacterial growth. Food should sit out for no more than one hour when temperatures are at 90 F, according to the U.S. Food and Drug Administration. In cooler weather, you can safely refrigerate the food and reuse it within two hours of serving. Bring disposable aluminum pans, plastic bags and other containers to store leftovers.
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