A growing number of brewers are looking at alternatives to isinglass as a clearing or ‘fining’ agent in their beers, the 2017 Good Beer Guide (GBG), published by the Campaign for Real Ale, CAMRA, reports. Isinglass is made from the swim bladders of fish – and as more and more drinkers today are vegetarians and vegans, brewers are looking at alternative ways to serve crystal clear pints.
Isinglass is added to casks of beer before they leave the brewery. A natural chemical reaction attracts yeast and protein and drags them to the bottom of the cask, leaving clear beer above.
Good Beer Guide editor Roger Protz says: “Isinglass is odourless and tasteless and doesn’t impact on the pint in your glass. But as it’s derived from fish, many drinkers are unhappy with its use in the brewing process.”
As a result, a number of brewers are either producing unfined beer that is slightly cloudy or are using alternative clearing agents. The Marble Brewery in Manchester uses silica and Irish Moss as clearing agents: Irish Moss is also known as carrageen and is a type of seaweed. It is widely used by brewers to clarify beer after hops have been boiled with malt and brewers are investigating whether it is suitable as a fining agent in casks of finished beer.
Experts at the Centre for Bio-energy and Brewing Science at the University of Nottingham are analysing a new role for the hop plant as a clearing agent. The department is chaired by Katherine Smart, who has been seconded from international brewer SABMiller, with MSc courses run by Professor David Quain and Dr David Cook. There is a fully operational micro brewery where students and young brewers can make beer and the course scientists are looking at using a blend of “spent” or used hops and fresh hops to attract yeast in cask and enable beer to “drop bright”.
Roger Protz says: “The easiest solution is not to use any clearing agents. I have seen at first-hand how brewer Justin Hawke produces his ales at Moor Beer in Bristol. Justin is an American from California who fell in love with cloudy wheat beers in Germany when he was stationed there doing military service.
“He moved to Britain and bought Moor Beer where he doesn’t use isinglass as he believes it strips some of the flavour from beer. As a result, his IPAs and other beers are served naturally cloudy in pubs and he says there has been no consumer resistance.
“Not only are drinkers happy – but so are fish!”