Batching and scaling

Recipes are written one drink at a time, which is right for learning them and wrong for having people over. Batching is how you make the same drink twenty times without standing at a shaker all evening.

• Batch the shelf-stable parts. Spirits, liqueurs, syrups, bitters, vermouth. These keep, and a stirred drink batches almost perfectly.
• Do not batch citrus more than a few hours ahead. It dulls and browns. If a drink has fresh juice in it, batch everything else and add the juice on the night.
• Never batch anything carbonated. Add soda, tonic or sparkling wine at the moment of pouring.
• Never batch egg or dairy. They need the shake, and they won't keep.

A batched drink poured straight from the bottle over ice hasn't been shaken or stirred, so it has never been diluted. It will be noticeably stronger and harsher than the same drink made properly, and the usual reaction is to blame the recipe.

Add the water to the batch. A stirred drink finishes around 20–25% water by volume, and a shaken one a little more. So for a stirred batch, add water equal to roughly a fifth of the spirit and chill the whole thing in the fridge or freezer. Then it pours straight over ice and tastes right.

Scale by ingredient rather than by drink: work out one drink in millilitres, multiply every line by the number of servings, then add the dilution at the end. Label the bottle with what's in it and the date, because in a week you won't remember.