Sugar syrup concentration in cocktails

When a recipe calls for sugar syrup in a cocktail, and it is not further specified, what is the concentration? For example in the IBA recipes.

I assume it’s 1-1 sugar and water, while my friend assumes its 2-1 sugar and water.

It’s both/either. The standard is 1:1. If you prefer sweeter cocktails, it’s 2:1.

I keep several different simple syrups on hand all the time. I use 1:1.

Welcome, @mr_jp. While this question is a reasonable fit for the General Questions category, it’s an even better fit for Cafe Society, our forum for the arts (including cuisine). I’ll move it for you.

I’ve found that 2:1 seems to make more palatable cocktails than 1:1, at least if you’re doing classic cocktails. Those old ones like to just use sweet ingredients and call it good, when to modern palates, they’re super-sour.

Agreed that it can be either 2:1 or 1:1. I prefer 1:1 myself but have made it both ways at different bars/restaurants I used to work in.