Greyhound

Two likely culprits. Pith gets into the juice when you lean hard on a squeezer, and that bitterness is harsh rather than pleasant. The other is time. Grapefruit juice goes dull and faintly sulfurous within a few hours of squeezing, much faster than lemon or lime.

A rim, not a pinch. Run a cut grapefruit around the outside of the glass, roll it through kosher salt, and salt only half the rim so you can drink from either side. The salt suppresses bitterness on contact, which is why a Salty Dog tastes sweeter than the same drink without it.

It arguably works better. Juniper and grapefruit share aromatic compounds, so the two lock together rather than sitting side by side, and the drink tastes of one thing instead of two. Use a London dry. Modern floral gins get lost. Blanco tequila turns it faintly savory.

It does, and it is not a myth. Grapefruit blocks a gut enzyme that clears a long list of drugs, including some statins and blood pressure medication, and the effect lasts most of a day. If someone is on medication, pour them a Cape Codder instead.

A classic Greyhound calls for 45 ml (1.5 oz) Vodka, 120 ml (4 oz) Grapefruit juice. That single-serve spec scales cleanly — the recipe above converts it to oz and multiplies it for 2–4 drinks.

A standard Greyhound is roughly 11% ABV once mixed (before ice melt softens it further). That makes it a relatively light, sessionable drink — similar in strength to a beer.

A Greyhound is stirred, not shaken. It contains no citrus juice, so stirring keeps it crystal clear and silky instead of cloudy and aerated.