In the early days in Philadelphia, he claimed he would open and close the bar. I suppose you could estimate if he drank throughout the day what that might be approximately. While he wrote Post Office, I believe he said he would drink two six packs and a pint of Cutty Sark. During his later years, a typical writing session would be two bottles (sometimes three) of good German white wine (references to Bernkastel start to appear in the letters) What isn't clear to me is what the weekly intake was during various periods. Perhaps someone else would know here. John Thomas says they took dexaml, LSD, Dexadrine as well as DMT (the alkaloid in ayahuasca or yage (the powerful hallucinogenic plant from the Amazonian rainforest which William Burroughs was fond of). Vodka and Seven-Up.
There's an interesting passage on beer in a 1971 interview:
"Miller's is the easiest on my system but each new batch of Miller's seems to taste a bit worse. Something is going on there I don't like. I seem to be gradually going over to Schlitz. And I prefer beer in the bottle. Beer in the can definitely gives off a metallic taste. Cans are for the convenience of storekeepers and breweries. Whenever I see a man drinking out of a can I think, now there is a damn fool. Also, bottled beer should be in a brown bottle. Miller again errs in putting the stuff into a white bottle. Beer should be protected both from metal and from light.
Of course, if you have the money it's best to go up the scale and get the more expensive beers, imported or better-made American . Instead of a dollar 35 [SIC] you have to go a dollar 75 or 2 and a quarter and up. The taste is immediately noticeable. And you can drink more with less hangover. Most ordinary American beer is almost poison, especially the stuff that comes out of the spigots at racetracks. This beer actually stinks, I mean to the nose. If you must buy beer at the racetrack it is best to let it sit for 5 minutes before drinking it. There is something about the oxygen getting in there that removes some of the stink. The stuff is simply green.
Beer was much better before world war 2. It had tang and was filled with sharp little bubbles. It's wash now, strictly flat. You just do the best you can with it.
Beer is better to write with and talk with than whiskey. You can go longer and make more sense. But beer is fattening, plenty, and it lessens the sex drive. I mean both the day you are drinking it and the day after. Heavy drinking and heavy loving seldom go hand in hand after the age of 35. I'd say a good chilled wine is the best way out and it should be drunken (drank) slowly after a meal, with just perhaps a small glass before eating.
Heavy drinking is a substitute for companionship and it's a substitute for suicide. It's a secondary way of life. I dislike drunks but I do suppose I take a little drink now and then myself. Amen."