Thanks. I realized the humidity measuring was built in the digital thermometer and not the attached probe, so it measured outside humidity. So I placed the thermometer inside the box and it shows 83% RH.

I stick with PF tek since I don't have a pressure cooker (the large ones cost a small fortune), have plenty of BRF and also not needing high yields - it's just for starters. Then maybe I will order All American PC as the ones sold in Europe are either too small, don't have a gauge or don't provide enough pressure.