i think it would be cool to see how creative people would get ... get a headcount on how many people want to participate and have everyone do a 5 gallon batch have 8 or so different malts, some hops and give people the chance at 3 different yeasts and let people go to town - would be interesting to see what people showed up with. Keep the malts fairly simple/standard. As example:
10 pounds 2 row
1 pound light crystal
1 pound dark crystal
1 pound flaked
1 pound rye
.5 pound roasted barley
.5 pound chocolate
...and maybe another couple go-to grains
We could have 2-4 hops to use ... preferably varieties that people are unfamiliar with ... maybe a couple noble hops and a couple american hops (but keep away from cascade, centennial, and the rest of the usual suspects). Or another option for hops we could have 5 different hops and people need to draw 2 from a hat and use those.
yeasts could be an american (US-05), british (S-04) & even lager maybe? Instead of lager could do nottingham or another and have people draw the yeast they need to use ... but keep them all fairly similar yeast strains I'd think
People could use whatever grain they want ... if they want to use half the grains and not touch others, it's up to them. No style guidelines involved, people just vote on best of show.