From RondaSnow.blogspot.com:
There is two basic differences between the stuff on your spice shelf and the stuff on an herbalist’s supply shelf: amount and preparation.
To get a “therapeutic effect”, in other words, for an herb or spice to help fix something that’s wrong, it takes a good bit more of the stuff than you would use in cooking. The helpful stuff needs to be used in big quantities…like in capsules or pills, or concentrated through “decoction” which is more like a sauce reduction than a tea….read more
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