....
> So .. the question is .. can I add Elderberry flowers or something similar
> to get a flavor similar to that of the german Rieslings?
>
> If so .. how much do I use?
....

Charlie -
You sure can add some Elder flowers. They do add some aromatic,
floral flavors, which seem to work well with this style of white wine.
They won't turn your California Riesling into a German Riesling, but
they should bring it a bit closer. The WinExpert Piesporter kits
include packets of Elder flowers - I'd say something like a couple of
tablespoons for a 6-gallon batch. That ought to be enough to make a
noticeable difference in the flavor, and not enough to cause a problem.
If you decide you really like the effect, you can increase the
proportions in future batches.

Personally, I'm not normally a big fan of sweet German whites, but
everybody that's tried the Piesporter kits has loved them. Even the
4-week (Vintner's Reserve) kits get rave reviews. I've read that this
kit is one of WinExpert's most popular kits; based on the number I've
done (and how few bottles I have left to show for them), I can well
believe it.

Doug