Hello! I also love the Lakefront Brewery and when my husband and I were looking for reception locations it was high on our list. But we ruled it out because the interior, when filled with lots of people, is really REALLY loud. The brick walls just bounce sound around. Have you ever been to the Friday Fish Fry? It's almost impossible to talk to the person next to you because it's so loud. We were worried that elderly family members (and probably the rest of us too!) would not be able to enjoy themselves. It's possible that the brewery has come up with a solution or that you and your party won't mind the roar. But I would recommend going to a fish fry just to get the feel of the problem. I hate to take business away from my favorite brewery but I thought I'd just pass on our opinion. I still buy lots of their beer so I don't feel too bad :) Best wishes on your wedding!
Lakefront Brewery is super-awesome. We didn't get married there, but arranged a private tour for our out-of-town guests the day before the wedding. Everyone had such a great time - they can't stop talking about it! We ended up getting married at the Grain Exchange Room downtown. Another place you may want to check out is the Eisner Museum. I'm not sure how many people it can hold, but it's in the 3rd ward and has the brick/loft feel that it sounds like you're looking for...
Try The Iron Horse Hotel - very rustic.
They book FAST, so if you want to go with them, I recommend contacting them as soon as possible, even if you are getting married in 2011. I called them in July about my October 2010 wedding and they said they are already booked through 2010. I agree with pp that it can get loud in there so check out a Friday Fish Fry to get a feel for it.
I don't know much about the lakefront brewery, but if you are looking for rustic in terms of outdoors, the Schlitz Audubon Nature Center has a gorgeous reception hall.
I was also going to suggest the Schiltz Audubon Nature Center. I've seen some beautiful weddings there, and I think they can accommodate up to 225 for dinner.
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