Cella that is Refrigerated will stay white and not go bad, I just cut off a piece as needed to press into my bowl. I'm on my 4th kilo and never had any turn or go bad. Same with a Kilo of Vito's.
have you noticed from those 4 kilos, that the lather generated can vary greatly based merely upon the brush used? I started my current tub with a badger, it was good enough lather.. but using my nos surrey boar, the lather is so much better.
I prefer a Boar or a Horse Hair Cacjurro brush. Once broken in on most, the tips are soft but the backbone stays firm. For me, Badger brushes feel too soft or floppy. But come to think of it, when I do use a Badger brush Cella does seem less adequate.