How Long Properly Stored Dairy-Based Batch Cocktails Last

Unlike ingredients like syrups or bitters, dairy isn't an ingredient you typically expect to taste in a bar drink. But with awesome recipes like the milk liqueur (vodka sweetened with milk and sugar), or the brandy milk punch, batching milky cocktails for your next party will surely get you some easy "oohs" and "ahs". If you end up with leftovers, though, be extra careful as they come with rather short expiry dates compared to traditional cocktails. The answer depends on how much alcohol you've used.

Milk spoils because bacteria feast on its natural sugars — that's why an open carton lasts just two or three days before it turns sour. Alcohol, though, is bactericidal. It kills microbial growth at the root, which is why high-proof spirits have been humanity's longest-lasting preservatives for centuries. Combine them, and milk gains that same protection. There's just a caveat: Alcohol is only good at its job of keeping bacteria at bay at around 14% ABV. Lower than this, and it wouldn't have much of an effect at all, and your cocktail will still spoil after three or four days in the fridge.

If you've mixed your dairy cocktail particularly strong — above 14% ABV — it can be kept for weeks, sometimes even months. And the good news is that batching doesn't change this timeline. A large batch stored properly will last just as long as a single serving would, so long that you store it correctly.

A refrigerator is non-negotiable for dairy cocktails. The higher alcohol content buys you more time, but it never eliminates the need for cold storage. After the party, if you realize you've got a few glasses of cocktail untouched, move quickly – they may start to taste gross in as little as two hours sitting on the counter. Pour the contents of the glasses into a lidded container (a clean mason jar works well) to keep them sealed and protected from the air, then refrigerate. Whenever you're ready to finish up, just pour or ladle as much as you need — it really is as easy as that.

The convenient bit about dairy cocktails is that, if they run into any problem, you'll usually be able to spot it very fast. Before you take a sip of a boozy creamy slushy, take a close look at it. If you see any discoloration, particles suspended in the liquid, or a sheen that shouldn't be there — toss it. Same goes if it smells sour or off. Your nose and instincts are your best tools here. If they tell you something's off, odds are good that it is.