I do this! After the first year's tea turned the beer too bitter for my liking. Tincture all the way! Everyone liked year 2 over year 1 at Christmas Eve! I used roughly 4oz of my extract.My only fear with this would be the introduction of some kind of infection. I am doing an experiment this year. I have always followed the original recipe guidelines for adding spice. This year I made 11 gallons, which I will split between two kegs. In one keg I will add spices in a tea. In the other keg, I will add a tincture of all the spices I have been steeping in vodka for a few weeks. Like a spice extract. I am interested to see if there is any difference.