The cardboard draws moisture out of the mayonnaise. Any paper product draws moisture from anything moist close to it.
By Rosario (Guest Post)
08/01/2006
It works because the cardboard holds bacteria and moisture that speed up the mildewing of the mayonaise. I always remove the cardboard from inside the top.
By
08/01/2006
I agree. Cardboard is a porous material and with the moisture too, it could encourage the growth of micro-organisms or mould.
By
07/31/2006
My guess is that the cardboard/paper would attract the moisture in the jar and that would encourage mold to grow on it. Pam in RI
By thrifty (Guest Post)
07/31/2006
I remember hearing this once, but cannot remember if there was a reason given. Perhaps the cardboard isn't "acid-free" or "antibacterial"?