Walk along Neiderdorf from Stadelhofen towards the Church..there is a whisky shop on the left called Liquid Perl, he sells a lot of good whisky and allows you to try before you buy.
There is another great shop further up nearer past the church on the right hand side...its off the main road but they have a sign on the street pointing the way, they sell whisky in vats and allow you to take as much away with you as you can afford.

Edit...also the Rapperswil brewery makes a nice whisky.