How much is inside a keg? Any college sophomore can tell you it is 15½ gallons, but how many servings is that, and how many gallons should you plan for each guest? On Saturday night, we decided to find out.

Besides the "half barrel" 15½ gallon domestic, the keg family also includes a 13.2 gallon import keg (on the right), the 7.75 gallon "pony" or "quarter barrel" keg (left), and the 5-gallon "sixth barrel" keg (center).

Unfortunately, they only sell kegs with beer in them, and that much beer was certain to have a deleterious effect on our study. We decided to do the same thing that NASA does: Invite a hell of a lot more scientists to help out. I printed off some fliers and handed them out at a nearby petrochemical engineering convention.

Buying beer in a keg is different than buying it in cans. For one thing, you have to provide your own drinking vessels. Regular folks use these red cups, sophisticated socialites use glass pint glasses, and movie stars and royalty prefer footwear. Thanks to a generous contribution by Z. Birkenbuel, I was able to buy a fresh, cold keg of Michelob from my local Beverages, & More. The keg was $87, plus a deposit.

The two keys to serving a keg of beer are keep it cold, and don't shake it up These can both be tricky. First of all, a keg won't fit into your refrigerator. Well, it might, but you will have to tear out all the racks and the vegetable-drawers. You are much better off putting the keg into an empty garbage can and packing the surrounding space with ice. My thanks to Greg Ward and Coffeeworks for supplying a truckload of ice for this keg. Shaking the keg creates unwanted foam. This is most likely to happen when you are wrestling the keg out of your car and dragging it into the house. One hundred and thirty-six pounds of beer can take you by surprise. Do not roll the keg into the house.

Instead the old style pull-tab, the top of every modern keg is equipped with a theft-proof pressure-activated combination lock-style valve. To circumvent this system, beer retailers will rent you a "black bag" of burglar-tools, including a tap, stethoscope and waterproof bib. I, of course, had to try it the hard way and immediately set off the alarm.

Finally the beer was tapped and ready, so I went over some last minute party preparations: Dusting off my collection of polka records, clearing all the opiates out of the medicine cabinet and vomit-proofing the furniture. At around 9:40pm, the first guests arrived: Jane, Rob Berry from RetroCRUSH and his friend Steve. In order to keep track of the number of beers that the keg dispensed, I decided to take a photo of each cupful in its owner's hand. This scheme meant standing by the keg the whole night, but it turned out that the keg was an epicenter of party action, so I was never lonely. Here is a photo of Summer filling her first beer.

Although beer was the star of the party, there were also the makings for some other beverages in the kitchen. Not all people enjoy the bitter taste of beer, so it is a good idea to have some delicious vodka or bourbon as a taste alternative. As more and more people arrived, an array of full red cups continued to flow from the keg. I could hardly believe how THIRSTY everyone was!

At around 11pm, the party was in full swing. People started talking to strangers, non-smokers began smoking and lousy jokes were pronounced brilliant... the beer was working perfectly!

Sometimes guests had to wait in line a few minutes for a new cupful of beer. The maximum flow was about six (red) cups per minute. I knew that the beer would come out faster if we could increase the internal pressure. We tried heating the keg inside the oven, but we couldn't get it to fit inside without removing the racks and the vegetable drawers.

The alcohol had different effects on different people. Some people slowed down, some people became more animated. For example: Cheryl tried on my boxing gloves and Tony challenged her to punch him in the stomach.

The first cup of beer was spilled at 11:30pm. At about this time, I had taken about 80 photos, and my battery died. Thankfully, Intel engineer Christopher Loental had brought his own camera, and he graciously loaned me his battery.

At exactly 12:30am, three hours after being opened, the keg ran dry. Some guests silently made a switch to hard alcohol and others banded together, forming small but effective beer search parties. Paradoxically, people who had the strongest desire for additional beer were least able to make the voyage. Some of the search parties returned in triumph! Others returned in jaguar. Here, from left to right are Kizzy, Ambur, Uli and Ichiro, representing the crossover from keg cups to cocktails and beer bottles.

The active ingredient of Michelob is ethyl alcohol, or C 2 H 5 OH. Michelob contains 4.9% alcohol, so a keg contains 97 ounces of alcohol. This is enough alcohol to bring 41 men over the legal driving limit in California. A little more and you could probably get them to sing and dance. In our experiment, two guests passed out and two guests threw up. Whenever you are serving this much beer, it is a good idea to have either snack-foods on hand or paramedics on duty.

As 2am turned to 4am, guests filtered out and made their way home, lingering on the front porch.

The house was almost empty, except for the contest Mike, Wes and Summer were having in the kitchen. The party was a big success, and the house had survived without anything getting broken. It wasn't until later that I found out about Leila's car window.

Here are photos of the 141 beers filled by the keg, in order. I asked people to indicate what number beer they were enjoying with a show of fingers. Only 26% of the beer was consumed by women, so they are underrepresented in this set of photos. Some women avoid beer because of the calories, and at 25,810 calories per keg, who can blame them?

Our keg had served 141 cups of beer at a cost of 62¢ each. 141 cups is enough for an awesome 7-story byramid!

A similar quantity of beer in cans requires 6½ cases, or 165 cans of beer. Beer sold in cans is about 50% more expensive, but those cans are a hellovalot easier to sneak into traffic school.