
Kirschwasser is a clear cherry brandy — an eau-de-vie — distilled from whole fermented cherries, stones and all, and bottled without sugar or wood.
Where kirsch is an accent — a barspoon floated on a drink, a dash for aroma — another unsweetened stone-fruit eau-de-vie will stand in and simply change the fruit: plum, mirabelle, apricot. Where the drink is built on it, as the Rose is, nothing else will do. What never works is reaching for a sweet cherry bottle instead: the sugar alone pushes a balanced drink into syrup.
Maraschino / sweet cherry liqueur
Both take their almond note from cherry stones: maraschino is distilled from marasca cherries infused with their stems and leaves, kirsch from whatever cherry the distiller has, crushed stones and all. The difference is what happens afterwards — maraschino is sweetened into a liqueur at around 32%, kirsch is bottled dry at 40–45%. Replacing maraschino with kirsch removes the sugar and raises the strength, so the sugar has to be added back with syrup: half a barspoon at a time, tasting as you go.
The cherries go into the ferment crushed, stones included, and it is the stones that give the glass its bitter-almond edge rather than the fruit itself. Nothing goes into wood: kirsch rests in glass or steel, because oak would smother a cherry aroma this delicate. The drink it belongs to is the Rose — dry vermouth and kirsch, poured at the Chatham Bar in Paris around 1919, two parts to one with a dash of raspberry syrup, redcurrant in many later versions. David Embury, whose 1948 Fine Art of Mixing Drinks remains an opinionated foundational text, argued for the reverse proportions: three or four parts kirsch to one of vermouth, which gives a drier and far more aromatic drink.
With no sugar and no wood in it, an open bottle changes very slowly, and the freezer does it no harm. The one thing worth doing is decanting the last third into a smaller bottle: what eventually flattens the fruit is the air standing above the spirit, not the passing of time.