mould in a kitchen unit

[thomas14]

I have a problem with mould growing in a kitchen base and wall cupboard.
It is only on the back board of both units and not on the wall it's self or on the sides of the units .
I have used a damp meeter and I seem to have no damp in the wall or floor. The Kitchen is all new with floating timber floors and all newly decorated with no other sign of damp or mould.
the unit at the top is a glass front with glass shelves sitting on granite and the bottom unit is a standard base. They both have a small gap behind and are not directly against the out side wall.
When you wipe off the mould the timber back board is in no way deteriorating so is this purely down to ventilation ?

Thanks

 

[JohnD]

how far is it to the nearest sink, waterpipe, drainpipe, washing-machine, kettle, dryer or other water-containing or steam-producing thing?

does anyone drape wet washing around the house?

how and when is the kitchen ventilated?