Hello Spirit
Thanks for your reply!
The funny thing is that it only happens with *fresh pressed* juice that I make myself. When I substitute with a fresh pressed juice (pasteurized) from my health store, then there is no such reaction.
This leads me to think that there is a compound in freshly pressed juice that causes the reaction - but gets degraded soon.
I am hoping that its a cleaning reaction and not that apples are bad for me!