60 ml Bourbon, 8 leaves Mint, 15 ml Simple syrup, 1 Mint sprig
The julep cup
Silver or pewter, with the ice piled above the rim and a frost on the outside.
Where it comes from
A julep cup is a metal beaker - silver, pewter or something plated - with crushed ice heaped above the rim and a sprig of mint on top. The Kentucky Derby's association with the drink is long, but its official julep glass dates only to 1938: the race has not always handed out silver cups, and the Mint Julep was not invented for it.
What metal does is plain physics. It takes the cold of the crushed ice quickly, so the outside of a full cup frosts within minutes and the drink inside it stays cold while it is being drunk. The same property means the cold leaves as fast as it arrived, so a julep is a drink to make when you are ready to drink it. Silver is the classic because of how it looks when it frosts, not because it holds anything better than pewter does.
What to look for
Heavy, with a good foot, and no lining to flake. A pewter cup does everything a silver one does for a fraction of the money.