In short, because it can taste better.
A spirit-forward cocktail is one where the spirit is the hero and the citrus, the sugar and the vermouth play behind it. That is a question of balance, not of what keeps. What lets a drink be bottled ahead is having no fresh ingredients in it, and plenty of spirit-forward drinks qualify. Mixing and bottling them in advance makes them quicker to move and quicker to serve. That is convenience. It is not ageing.
Citric juices like lemon and lime can be pretty faithfully recreated from their constituent parts: malic acid, citric acid, tartaric acid and so on. That allows cocktail makers to use those flavours in a stable way.
Egg white, fresh fruit juice, and champagne, not so much. Not yet anyway. In fact, if someone tells you that they have a canned Piña Colada for you, ask yourself where the cream of coconut and the fresh pineapple juice came from. It is good to know what is possible before you imbibe.
Cocktail bars will often batch popular cocktails to their own recipes, to speed up service. In 2005 Tony Conigliaro, the much celebrated London bartender, started to investigate this further. He noticed that drinks containing vermouth or sherry would oxidise, rounding out the flavours and creating a smokiness and a subtlety that were not there in the freshly mixed drink. The aged Negroni and the aged Manhattan were born.
Jeffrey Morgenthaler in Portland took it a step further, ageing large batches of premixed cocktails in oak whiskey barrels. The results were remarkable, and the cocktail world came alive with experiments in ageing.
At Myatt's Fields we age most of the core range. We have spent years on it: ratios, cutting vermouths and sherries, testing them against different spirits, working out which adjacent ingredients will hold and which will not. It is slow, and it is the reason the drinks taste the way they do.
Ageing a cocktail is part art and part chemistry, and it is one of the better things to have happened to drinking in the last twenty years. We are glad to be able to hand it to you in a bottle.
