If it's been in the fermenter 4 weeks already, fermentation should be virtually done and what's happening now is just conditioning. So a minor change in temperature for a week isn't going to hurt anything. But I'd like to know how much cooler you are talking about. Are we talking a few degrees C, or more like 20°C to 5°C?
Read my brewing blog here! Last of the Zyme Lords
BOUSIRIS BOUERY - Home of the Zyme Lord
The cans of Leinenkugel's had masking tape on them with JOHN'S printed in ink. Amy looked around me and said, "John is protective about his beer, isn't he?"
"I put that label on there. When company comes I want them to know the Leinie's is his, not mine." - David Wong
Anna Livia Irish Stout
Melancholy Bill's Infinitely Sad Pumpkin Ale
Lucian's Landing Ginger Metheglin