how long do mixers keep?

I was wondering if anyone knows how long common drink mixers and condiments keep. I was just cleaning my fridge and found the following items:

– 1 bottle of vermouth, 3/4 full, age unknown
– 1 bottle of Tom Collins mix, 1/2 full, at least six months old
– 1 bottle of Angustura bitters, 90% full, a year old
– 1 bottle of grenadine, 1/2 full, a few months old

(The bottles themselves give no info. on how long they keep, and the “sniff test” tells me that all of these items are fine, or at least, not obviously off…but what do I know?) I’ll sometimes buy drink mixers for certain occasions, make a round or two of drinks, and then have almost a full bottle left. Seems wasteful to throw away an almost-full bottle of vermouth away (and I like the idea of having some at hand, just in case a guest wants a martini, etc.), but it also seems risky to serve these aged mixers. Does anyone know how long this stuff lasts? (And if it goes bad pretty quickly, then why don’t they make tiny bottles of this stuff? E.g., to use up all of my bitters in good time, it would probably take 200 people who all wanted a Manhattan on a particular night…)

The vermouth and bitters should be fine just about forever, as long as the tops were on tight. The alcohol will keep the vermouth good; as far as bitters, I’ve had bottles for years and they’re fine.

The grenadine and tom collins mix have the benefit of sugar; basically, they’ll start to mold if they go bad. I’m guessing neither is even close to bad seeing as you kept them in the fridge. I’ve had bottles of grenadine forever - I never use much of it.

Why would you keep these in the fridge anyway? I don’t know about tom collins mix, but the rest are nearly unspoilable.

I asked my original question because I wasn’t sure if these items are spoilable or unspoilable. Guess I didn’t pay much attention in Home Ec. class…why are these items obviously “nearly unspoilable” to you?

Both bitters and vermouth have a fair bit of alcohol in them; alcohol is a preservative. If the container is closed tightly, it will last forever. That’s why you see people drinking bottles of wine that are hundreds of years old. And wine has barely the amount of alcohol that either vermouth or bitters has.

Sugar - which you’ll find in great amounts in the Grenadine and Tom Collins mix - is also a natural preservative. Probably not as effective as alcohol, but add in the refridgeration and you’re good for many years.

Bitters and vermouth contain enough alcohol to prevent bacterial or mold growth.
Grenadine contains about as much sugar as maple syrup. That reduces the water activity to a level where surface mold is about the only thing that might grow on it.

So juices (lime juice, lemon juice), too, should last forever, because they’ve got so much sugar in them? When I was cleaning my fridge, I threw out a can of pineapple juice that had actually turned black.

No. Natural juices run only up to a few tens of percent sugar. That makes them good food for yeasts and bacteria. 60% or more sugar is needed to prevent growth. While the acid in lemon juice will slow down down or eliminate bug growth, it’ll still air-oxidize and develop an off flavor. The same will happen with lime and pineapple juice.

Got it…thanks for helping to keep me from poisoning my guests!