It's Open Farm Weekend[/url:2xiafsbv] in 't North this weekend. Armagh Cider is open[/url:2xiafsbv] Saturday and Sunday -- it's a really interesting tour, and they also have a super state-of-the-art shiny bottling machine, for those interested in such things.
I see also that Hillstown Farm in Randalstown is on the list[/url:2xiafsbv] for Saturday. It doesn't mention that their new brewery is part of the day's offering, but somebody might be willing to show you round if you rock up and ask nicely.