Isinglass Finings are used to improve the clarity of your brew. It also removes unwanted compounds, improving flavour. Isinglass is a form of gelatine obtained from the air bladder of the sturgeon and certain other fish such as Cod. 100ml will treat 25 litres of beer. Available 1 litre bottles. Ingredients: Isinglass, Preservative (223), Malic Acid.