I'm in the middle of brewing my first Hefe (started on the weekend), and am really tempted to just pitch onto the yeast cake and repeat the process over again, adding rhubarb to to secondary. My mother has a ton of rhubarb and it'd be great to use some of it before the season's done! Should add a tartness to the beer, much like adding citrus.
Current recipe:
2.25 KG Wheat Malt
1.75KG Pilsner Malt
0.5 oz Tettanger @60mins
0.25 oz Tettanger @15mins
Pitched with wyeast 3068 Weihenstephan Weizen Yeast
Rack to secondary @ 7 days
Add 1 lbs pasteurized fresh rhubarb.
To Pasteurize: Bring water to 160F, submerge rhubarb for 15 mins without boiling. Cool and add to secondary.