Mark, do you know of any biology behind why weisse/wit strains tend to pump out a lot of sulfur compared to other S. cerevisiae strains? To me, they're worse than many lager strains with the H2S production.
The jury is still out on whether or not strains such as W-68 (Wyeast 3068) are truly S. cerevisiae or if they belong to their own Saccharomyces species. On one hand, W-68 top crops like a domesticated yeast, and shares many genetic markers with S. cerevisiae. On the other hand, it produces flavors and aroma compounds that are more common with non-S. cerevisiae yeast strains. This weirdness is not without precedence. If you view the graph on page 1617 of the following publication: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2556262/pdf/1610.pdf
, you will see that the Duvel strain that Wyeast sells (GSY161 in the paper) groups with NCYC 361, which is a Saccharomyces diastaticus strain.