You'll have remembered from Robin's blog back at the turn of the year that we've been experimenting with omitting isinglass from cask beer. We've been using a vegan friendly alternative in a few of our more recently casked beers which appears to perform at least as well as isinglass. One of the problems we have with isinglass is that, because it is an animal based product, it is relatively short dated. We try very hard not to let green beer (beer that is not quite ready) go out which means that, if a cask sits in a cellar for longer that usual, it runs the risk of the isinglass denaturing (going off).
In an ideal world, all beer would be drunk in it's optimum condition, pale and hoppy beer fresh, darker ones with a bit of aging on it. In reality, we don't live in an ideal world and there is anecdotal evidence that well kept cask beer actually improves with some age on it. So it makes sense, then, not to use a fining agent that has a six to eight week date on it.
Moreover, we are being asked on a weekly if not daily basis which of our casks beers are vegan friendly. All our keg and can beers have always been unfined and our dark cask beers have been unfined but we've used isinglass in the pales, ambers and reds. We feel this is confusing and we wanted to adopt a consistent process.
So, tomorrow we'll be racking gyle number 272 of Skylarking without the assistance of isinglass. It's what we said we'd do at the beginning of the year and, now we've had time to test it properly, we're putting it into action.