The confusion comes because there are different types of particles that cause different types of hazes and different types of finings are used to remove them.
- Copper finings originate from seaweed (irish moss), have a negative charge and are added in the copper (kettle) to help remove protein.
- Auxiliary finings can also originate from seaweed or can be silicate based. They have a negative charge and are added to the fermenter, conditioning tank or cask to help remove protein.
- Isinglass finings originate from the swim bladders of some tropical fish. They have a positive charge and are added in the conditioning tank or cask to help remove yeast.
A large reason for the action of the finings is due to the charge they have. Opposite charges attract so negatively charge finings attract proteins (which are positively charged), and positively charged finings attract yeast (which is negatively charged). This is why finings cannot be used interchangeably and finings made from seaweed will not help remove yeast. Neither will PVPP so don't start on that. Or silica gels either. If you're after more information I recently posted at great length about hazes caused by non-microbiological particles, and part two on microbiological hazes is in the latest issue of the SIBA journal and will be posted here in due course.