Hi Marco,
I can delete the post if you wish? From the title it sounds like you were wondering what the yellow honey-coloured liquid in the bags was. Here’s a photo of something similar in the bag on the right:
The liquid is nothing to worry about it – it’s just waste metabolites that the mycelium produces as a byproduct whilst growing across the substrate. You can wash it away with water when you cut open the bags to fruit if you wish.
Hope this helps.
Best wishes,
Adam