I used to want my particles as fresh as possible, preferably still warm as I was catapulting them in.
Then I fished a water with hemp I'd prepared Friday, by Sunday it seemed to get better and better as it got sticky and slimy.
Pigeon conditioner is another one that as it smells a bit fermented is better.
Even so, I had some that went beyond that, that I thought was off, with mould appearing on the top, so I poured it in the margins for the swans, and within a few minutes carp were on it.
I simply don't take particles home, either poured on the bank to keep the swans and geese happy or prebaited.
If I don't go, I end up with a bucket of bait in the freezer. In fact I've just pulled a bucket of hemp out today for use tomorrow. I've got some ice cream containers full of particles that I'll leave in until the morning for the day after.