My lump of Cheesepaste & breadpaste has been going for years now it's been in and out of the freezer for as long as I can remember.
I just add some newly kneeded cheese & bread paste to the ball as the ball gets smaller each time I use it (which isn't as often as it used to be).
It's particularly good when; even on a hot day; it starts to sweat and feels cold to the touch, it's probably the aminos breaking down that makes it feel like that and makes it so atractive to the fish.
I like adding raw liquidised onion with no lumps in it.
The winter Chub on the Kennet really love it and the Roach on my local estate lake go mental for it in the early spring.
I have caught Barbel on it but not as often as the Chub and Roach so it isn't my first choice when I am after the Beards.
The smellier it is the better.