How do "dormant" yeast interact with the beer?

Those who wish to understand the mechanisms by which diacetyl is formed in brewing may wish to consult Takashi Inoue's (Dr. Diacetyl) "Diacetyl in Fermented Foods and Beverages"
avaialble from the ASBC or Amazon: http://www.amazon.com/dp/1881696154/?tag=skimlinks_replacement-20

I just remembered something that may be of practical value to readers WRT diacetyl. Since it is formed non-enzymatically in the beer, not in the yeast, there is a simple test you can do to tell you when you can take the beer off the yeast. It involves heating a sample of the beer which speeds the decomposition of alpha acetolactate into diacetyl. In a nutshell, if heating a sample of the beer increases the diacetyl aroma then there is residual AAL in the beer and you should leave the beer on the yeast until all AAL is converted to diacetyl and the yeast have absorbed (and reduced) that diacetyl.

This was first brought to my attention years ago by George de Piro - former pharmaceutical chemist, homebrewer and now head brewer at C. H. Evans in Albany, NY who posted it to HBD way back when. So I did a search on de Piro and diacetyl and found this website http://www.professorbeer.com/articles/diacetyl.html where he describes the simple (no lab gear) procedure in some detail and gives instructions on how to interpret the results.

PS: Just tried this with the Kölsch I have in the fermenter right now and was planning to transfer tomorrow. I passed with flying colors so I'm ready to roll!