Joanna…
Gouda is one of my most made cheeses and I always wax as soon as they are dry to the touch (usually 3 or 4 days if left at room temp or no more than two days if drying in the cave). I have never had a failure following this procedure.
Hope this helps.

Dave

Dittos to Neil.  As long as you have a good dry rind formation you will be OK to wax.  Or, on the other hand, the cracks may present a problem in waxing.  I had a Jack that had a lot of large open spots on the surface, and instead of waxing I bandaged it.  That way, I was able to fill all the holes (or in your case, cracks) with shortening and not have to worry about tearing up the wheels when I removed the wax.  Mine is still in the cave so I can’t tell you how it turned out - but its something you might want to consider.  I really like the bandaging technique.  I have 3 bandaged cheeses in my cave:  a Gouda, a Colby and the Jack; and they are all standing up quite well.  But they do require extra turning.