
Lime cordial is a sweetened lime concentrate made from lime juice, sugar and water, used to add both sweetness and lime flavor in one go.
It is sweetened, preserved lime rather than fresh lime, and that difference is the whole point of a Gimlet. Figure 8–15 ml, and it brings its own sugar, so the recipe usually drops the syrup. The cordial gives a rounder, slightly cooked citrus with the sugar built in; the same drink made with fresh lime and syrup is a sharper one. Gin is the traditional base — cordial and gin is a Gimlet — and vodka works the same way. Measure it as a sweetener, because that is most of what it is.
The usual stand-in is fresh lime juice with 2:1 sugar syrup in equal parts. To start, use 5 ml of each for every 20 ml of cordial; the drink comes out a little shorter. Then taste, since cordials vary a lot in sugar and acid. The drink tastes fresher and sharper than one made with the bottle.
Fresh lime juice
Sour and unsweetened: without syrup it leaves the drink sharp.
Lime syrup
A lime-flavored sugar syrup; in place of cordial, add fresh lime juice to taste to bring back the sourness.
Sealed at room temperature for months, refrigerated once open. It is a preserved product and does not go off quickly, but the aroma flattens with time and an old bottle tastes mostly of sugar.
Southern / Louisiana-style whisky liqueur, Triple sec