If you look carefully you can see the discoloured brown at the bottom of the post, it is bit mushy too, with a 60 year old kitchen with no ventilation, it's not good. It smells and causes allergy symptoms. It must have been the 3 days of hot weather we just had that trigger it, deep mould in the wood. That and changing the insulation from a to b with still some a, the 2" of foam board.
This little openings are working well for air flow and are practical as access the storage area. I can put some shutters or doors to close sometimes. But i think i have to cut the hole above the kitchen aswell is where the problem is starting, even with the hood vent used there will some be excess of humidity. Means some venting into the bedroom above. The problem being noise or smells passing through, the house is a small bungalow only meant for 1-2 people it will be okay.