Last night I made bangers and mash. I thought it would be a great idea to make a guinness and onion gravy to go with it. Unfortunately my gravy came out tasting more like gasoline than food. It was inedible and unsalvagable. I hope that by posting my recipe and process someone can help me figure out what went wrong? And this is not a problem I've encountered once, sometimes my gravy comes out bitter and I can't figure out why. 1. I sweated some onions in sausage drippings in a stainless steel pan. I cooked them slowly for about 10-15 minutes until they began to caramlize. 2. I add a pinch of dried thyme, a tsp of chicken Better Than Boullion, a pat of butter and a spoonful of flour and let that cook for about a minute. 3. I add a touch of water and a whole can of Guinness. Also a shake of Worstcheshire sauce. 4. I reduced it slowly for about 15min. Then I tasted it to adjust the seasoning and was horrified by the bitterness. I added a little sugar. it helped but the bitterness was still there. Then I added a little dijon and some cream. Still bitter. Then a squirt of lemon. Still bitter. Finally I decided it was hopeless. Where did I go wrong? I have used Guinness very successfully in poaching corned beef and braising beef stew. Why did it come out bitter?