Imperial B51 Workhorse - Wyeast 1581 Belgian Stout - Kasteel Yeast

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Feb 19, 2012
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I am post to write about experiences with this yeast.

I found a link a while back regarding the source and equivalent strains from white labs and wyeast (photo attached).

This is reported to be the Kasteel yeast.

I brewed an amber with 99% Local 6-row Vienna malt, 1% midnight wheat, Hersbrucker hops. I aimed my mash for 154, but got stuck at 148. 6-row malt seems to suck more heat, or perhaps these local malts have a higher percentage of moisture. Ended the boil at 1.055. Pitched at 0.75Mil/mL/P. Fermented at 68 (low end for a clean fermentation). Finished it up at 75 to clean up and fully attenuate. Ended at 1.010 for 6.05% ABV, 81% AA. A bit drier than intended, but a factor of the low mash temp.

At the first week it was HEAVY on clove phenolics, but after a week in cold conditioning it rounded out and produced a much maltier beer.

For a yeast advertised as "clean," this had a high amount of clove and other spicy notes. What I had hoped for was almost a bock like Amber with slight Belgian notes. What I got was a heavy-handed, earthy Belgian with malty notes. It's an interesting yeast, but certainly suited for a beer that is meant to be heavy on the Belgian clove flavors. I will perhaps try again on a Belgian Stout (per it's name), or maybe on a strong ale (8%+).

Cheers and happy brewing.