I have read about gruits (beers made with no hops, using other herbs in their stead). Apparently, this was a commonly used technique before hops became so prevalent. Mugwort seems to be one of the most common herbs used in gruits.
How does mugwort differ from hops, in terms of usage (how much to add, and when) and in the final product (taste, head retention, shelf life, etc).
Have you used any other herbs? How do they compare to hops?
I'm afraid I can't comment from experience, but if you're interested in "weird beers," I highly recommend Randy Mosher's "Radical Brewing." He has a 6-page list of herbs and spices for brewing, and an updated and safe (2 of the 3 traditional gruit herbs are dangerous - bog myrtle is the safe one) gruit recipe. He lists mugwort as a bitter herb, but doesn't give any sort of bitterness rating. He also doesn't list any taste qualities, which suggests to me that any taste contribution is overshadowed by the bitterness. He does suggest adding low-alpha hops to gruits purely for their preservative qualities, so using mugwort instead of hops would definitely shorten your shelf-life.
