My experence is also very limited but I am familiar with both of these through several meads made by local folks. When judging meads I seem to more easily pick out the Narbonne 71B character in Trad/Show category.
Commonly you see the following yeast selections:
D47, 71B for Sweet/Semi-Sweet Traditional and Show Meads
K1V, RC212 for Dry Traditional Meads
71B for berry melomels
71B will usually create a mead that is a bit "softer" and more "fruity" than D47. Both produce fruity esters when they ferment, but D47 develops more phenolics that will produce a "spicier" or slightly "peppery" character in the mead. That phenolic contribution is enhanced when D47 is used and "sur lie" is incorporated in the aging of the mead, since more of the phenolics are released as the yeast cells break down. D47 also contributes additional soluble polysaccharides that way, which will increase mouthfeel and provide a suggestion of additional sweetness.
I have often noted this peppery quality (D47) in mead flights. Aging on the yeast (sur lie) is still a bit beyond my skill level. Does anyone here attempt this?
My research indicates a lot more goes into yeast selection as meadmakers gain more experience. The true pro's integrate yeast selection into sytle/balance targets and honey/adjunct characters so that it all becomes a single concept. Schramm discussed this preconceptualizing the final result but I think it went over most of our heads at the time.
LOTS of Patience! Want a good Cider start by planting apple trees. Want a good mead start by creating your own strain of bees. (I have been reading Brother Adam's Bee keeping at Buckfast Abbey There was a patient mead maker.
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