How can I tell when simply syrup has the right consistency and sweetness for drinks? My bartender friend gave me this recipe: boil 1c. water w/1.5 c. sugar for about 5 minutes, til barely thickened; add 3-4 sprigs of rosemary, let cool, and strain (for champagne cocktail). I did all that (I thought). However, when I put it in fridge, the bottom half crystalized. The liquid on top smells great (like rosemary), but I'm afraid I might have reduced it too long and it might be too sweet. If I experiment the day before guests come, I'll ruin my good sparkling because it will go flat by next day. How can I tell when simple syrup is at the right consistency and sweetness?