Post #529247 by Chip and Andy on Mon, May 10, 2010 4:14 PM

On 2010-05-10 14:22, congawa wrote:
By the way, I have heard of people adding a little rum/vodka/etc to syrup to make it preserve longer. However, how much alcohol can you add to, say, 2 cups of simple syrup before it stops becoming a syrup and instead becomes a failed liqueur?

Brent

I have to give you a vague kind of answer and it involves some math....

To get your syrups up to a shelf-stable proof you have to add enough alcohol to get to at least 10% ABV, or 20 proof. Your best target is 15%ABV and with most home-brew you can get up to three months on the bar or up to nine months in the fridge. Every home-brew is different, some ingredients are just not compatible with storage while others will last longer than you.

For your two cups of syrup you should add 3 3/4 ounces of vodka. Make it easy and add 4 ounces and you should be OK.

And shelf stabilizing Sugar Syrup will NOT keep it from crystalizing. It will only keep it from growing. Well, it will slow down anything that may grow in there. Following Swanky's recipe for making Invert Sugar will last longest without crystalizing, every other method it is just a matter of time before your sugar syrup becomes sugar crystals again.