I am making Ina's beef bourguignon and my Cognac wouldn't ignite after many attempts. Why? After it failed to do so, I drained out the juices ( saved of course) as I thought maybe too many other juices. That didn't help. Next I warmed the Cognac with the vegetables, thinking it need to be warm and make the fumes rise. That didn't work either. The Cognac I used Chabanneau brand. I finally just simmered the cognac for awhile before putting in oven. Help!