Eastern buckwheat is know for the barnyard character, and if you compare a sample of Eastern and Western buckwheat side by side, you can tell the difference. Some people like both. I think the Western has more versatility, and it can be used with some melomels - I have a cyser aging now with 100% Apple juice and nothing but buckwheat honey and it still has a lot of aging to do, but the early results look quite good. That molasses/nutty character can be really good.
It can also do great things in a braggot, and in blends with other honey. I'm not sure I'd like a dry traditional with buckwheat, and generally speaking, I agree with those who think lighter honey makes better mead, but YMMV. A semisweet buckwheat traditional might be tasty.
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