This you don't understand and you're wondering if
she's making it up, so you ask how this is possible.
" It's actually a bit technical but you DID ask.
The pot is made of cast iron and iron is a porous metal and
absorbs flavors. When I bake a new cake in it a tiny amount
of the flavor from every Guinness cake I ever made goes back
into this one. Therefore making it taste better, but of course
I wash it thoroughly every time."