1/2 oz St. Louis Kriek Lambic Syrup (*)
1/2 oz Lemon Juice
Shake with ice and strain into a cocktail glass. Top with 2 oz of La Marca Prosecco.
(*) Reduced down with heat, then sugar was added. I did not get the exact amount that it is reduced down. As a starting point, consider Misty Kalkofen's Guinness syrup which reduces 12 oz of beer to 8 oz and then adds 8 oz of sugar (makes 12 oz syrup). Perhaps 12 oz could be reduced in half to 6 oz and add 6 oz of sugar (makes 9 oz syrup).
Two Tuesdays ago, Andrea and I stopped into the Citizen in Boston where Nick Korn and Sabrina Kershaw were bartending. For a drink, I asked Nick for the Queensbury which caught my eye on the menu the last time we were there. When I inquired about the beer syrup, Nick explained that bartender Chad Arnholt used to work at a bar where they had drinks that were topped with Lambics and other beers. As the beers went flat, they thought it was wasteful to dump them and figured out that made good syrups.