No one thus far has drunk sherry in a Pynchon novel that I have noticed. But sherry’s ghost does linger by a window during the Rathenau séance early in Gravity’s Rainbow. Milton Gloaming is telling Jessica about his statistical analysis of the paranormal investigations; Jessica’s “mad young gentleman” Roger is off in another room with Pirate Prentice:

Being transacted in some distant room, across a crown-and-anchor game with which chance has very little to do, billows of smoke and chatter, Falkman and His Apache Band subdued over the BBC, chunky pints and slender sherry glasses, winter rain at the windows. Time for closeting, gas logs, shawls against the cold night, snug with your young lady or old dutch or, as here at Snoxall’s, in good company. Here’s a shelter—perhaps a real node of tranquillity among several scattered throughout this long wartime, where they’re gathering for purposes not entirely in the martial interest.

Gravity’s Rainbow, p. 32.

Another Pynchonian instance of characters huddled warm in improvised family warding off for a moment Their deathly mechanical fingers. (Only in the UK would a chunky pint fit so neatly into this snug winter scene—I’m betting it’s one of those “dense, warm, unaerated pints” mentioned in Against the Day.)

The sherry I’m drinking is a Pedro Ximenez. Not the most English choice I realise, but it sure nails the cozy wintery brief otherwise. Pedro Ximenez sherry is made from sun-dried grapes, and the concentrated sugars lend it a rich, raisiny liqueur-like sweetness.