I'm going to be visiting the brewery this summer and am trying to figure out if there is a tasting room or other place to hang out and drink for a few hours there, or if I should just expect to have my one beer that is included with my tour ticket, buy some bottles and move on. Any info would be appreciated.
Oh, you can definitely hang out there. They offer additional pours/bottles for on-premise consumption. There's a little seating/"bar" area right next to where the self-guided tour begins.
This is why you could hang out there a LONG time - the Cantillon glass pours are cheap - the best bargain in Brussels, if not Europe (not exaggerating) at 2 euros a glass. Here's a photo of the price list taken at the tasting room last month. Makes me weep. This is a partial view of what the tasting room sitting area looks like -
Menu changes every now and then depending on releases, sometimes other things are included. Most importantly, Cantillon is just a magical place that is worth spending some time at!