If you want to drink some good beer and you’re in Milan here some reccomendation, tried and tasted directly 
I’ll update this post as soon as possible with other brewery/pub
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Birrificio Lambrate
This brewery has two different sales point, the first one here, since 1996, small but fashinating
and another here since 2011, more a restaurant pub
Both pub are in the upper west (Lambrate) area of Milan
link to the official site: Brewpub - Birrificio Lambrate -
Birrificio la Ribalta
Here you can taste some good beers and eat really good plates
This brewery with the related pub is in the nothern area (Dergano) of Milan
link to the official site: https://www.birrificiolaribalta.com/ -
The wall
This brewery/pub is in the northern area (Isola) of Milan
Here you can taste beers and some plates like sandwiches
link to the official site: http://www.thewallbeer.com/