I unfortunately haven’t made an alcohol intermediary method glycerite before! But I think it’s a great idea to experiment and see if you’d be able to tolerate the amount of alcohol left over after extraction. You could also experiment making both an alcohol intermediary method glycerate, as well as a regular glycerate. Glycerites can extract bitter compounds and I have seen herbal glycerites from roots. Some folks will do a strong hot water extraction before adding the glycerin, which you could also try. The other option is to use bitter herbs where we use the aerial parts, like Centaury, Wood betony, Yarrow, Wormwood, Mugwort and Chamomile. These would work totally fine with a regular glycerite.
I will do a little more research and let you know if I find anything else! In the mean time, for regular glycerites:
– Fresh plant extraction – you can use 100% glycerin
– Generally a mixture with 60% or more glycerin to 40% or less water is a safe ratio. You can also do a 75% glycerine to 25% water ratio. (try doing a hot water if you’re using roots)