For one I have read that if after the yeast is settled and the yeast is stirred up (for whatever reason) then gelatin will not help dropping the yeast out while isinglass will. Also I've read the complete opposite. Which one is true? Of course as I've read both I'd expect a good source for the claim.
Are there other differences between them? More than ethic/religious aspect of sourcing the collagen (I assume that pig gelatin is not kosher for example).
Looking around on the internet it seems that both do the same. Both products contain collagen, which bind to yeast and proteins.
The main difference is that for using gelatin the beer must be cold. For isinglass this is not necessary, but using isinglass is more difficult: the pH of the isinglass mix needs to be adjusted, and the isinglass mix needs also to be put in the fridge for a couple of days before adding it to the beer.
Culinary uses of gelatin: According to this, isinglass used to be a source of gelatin.
