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Brass Castle is a vegan and vegetarian friendly brewery.  We don't use any animal-derived products in brewing our beers.

In simple ingredient terms, this principally means no honey or lactose.

Crucially however, we do not use isinglass finings in our cask beers.  Mostly because we think that the addition of icky gloop created from the swim bladder of fish is disgusting, but also because it's unnecesssary.  What is isinglass?  Well - the manufacturers describe it thus:

- COMPOSITION An acidified aqueous suspension of collagen derived from the swim bladder of certain fish; and sodium metabisulphite

- APPEARANCE A translucent homogeneous viscous liquid

- ODOUR Marine odour and Sulphur dioxide

Essentially, it is a process aid that allows brewers to create crystal clear beer more swiftly than would otherwise be possible, thereby cheapening the brew cycle.  In the manufacturer's words: "Very large savings in both cooling energy costs and capital investment in tankage may be made as a result of shorter conditioning time that can be gained by treatment with isinglass".

Some people talk about 'fish gut' additions to beer and isinglass is what they are referring to, but we've never seen a brewer actually add a handful of fish guts!  Industrially-prepared isinglass looks more like semen.

Other reasons why we don't use isinglass:

1.  It artificially hastens beer clarification, meaning that the brewer does not need to concentrate so much on recipe formulation, yeast selection/health and fermentation profile etc in order to guarantee clear beer.  In removing haze particles, there is evidence to suggest that isinglass additions also remove flavour-active proteins and so strip flavour.  Brewers therefore use it to ensure that the beer LOOKS good, often at the expense of TASTING good.

2.  The addition of up to 1.5L of isinglass to a cask fiddles the publican (and therefore the drinker) out of 1.5L of beer.  Isinglass is cheaper than beer.  The publican has to raise the price of a pint to cover the lost quantity of beer in the cask - i.e. for two identically-priced casks of beer, the non-isinglassed cask will yield more beer. In addition, breweries pay duty based on the amount of "beer" in the cask - so at Brass Castle we pay duty to the public purse on a full 72 pints in a cask, (after exhaustive ullage surveys on the volume of beer regularly remaining in one of our casks), whereas most others pay duty on closer to 69 pints!

3.  Isinglass goes off.  Also, the "acidified aqueous suspension of collagen derived from the swim bladder of certain fish; and sodium metabisulphite" addition in a sealed cask of beer raises sulphite levels, reduces yeast activity, foreshortens secondary fermentation and can lead to a beer staling through yeast autolysis.


To achieve certified gluten-free status for Hoptical Illusion and our cans of Bad Kitty/Sunshine/Helles Lager/Hoptical Illusion, we use a Murphy & Son enzyme product called 'Brewers Clarex' - added in a tiny amount during fermentation.  Marvellously, it contains an enzyme isolated from a self-cloned strain of the mould Aspergillus niger.  Some breweries use it to reduce protein haze; but a lovely side-effect is a reduction in dissolved gluten.  Our certified gluten-free beers are tested through Brewlab, Sunderland, using the competitive ELISA testing protocol.

From December 2017 we began to produce all our beers to a gluten-free recipe.  Until we manage to generate our own laboratory testing regimes in-house, it is still prohibitively expensive to test each individual 'gyle' or batch of keg and cask beer.  Therefore, although all beers are brewed to a gluten-free recipe; only our canned beers and cask/keg Hoptical Illusion are certified gluten-free.