In an ideal world there would be no need for clearing agents, all beers would drop clear of their own accord. Unfortunately there are substances that have an influence on beer clarity. These substances generally need some assistance in vacating the brew.
There are three main haze-forming substances in beer; starch, protein and yeast. Providing the mash has been allowed to progress past 'starch end point' the former should not pose a problem. Starch haze should certainly not be present in an extract beer.
Protein haze is usually the result of inefficient boiling or excessive chilling of the beer. During the boil, proteins coagulate to form flocks which precipitate out on cooling, Brupaks Irish Moss and Protafloc assist this process. Proteins are positively or negatively charged depending on their structure. At the normal wort pH of 5.5 - 6.0 proteins are generally positively charged. Irish Moss and Protafloc are negatively charged which enables them to attract the haze forming proteins which will subsequently precipitate.
Yeast will form a haze if it is present in the finished beer at too high a concentration. Although given sufficient time the excess yeast should sediment naturally, in practice it is usual to employ a fining agent. The two main fining agents are isinglass and gelatine. Isinglass is produced from the swim bladder of the sturgeon and gelatine from pork. Isinglass is some three times more effective at clearing yeast than gelatine. Although ready-for-use isinglass is often seen for sale, it is only really effective for one month from date of manufacture (although some products have best before dates very much longer). Brupaks Dried Isinglass is available from all good home brew retailers. This product will last a considerable time in its dried state and for about 4 weeks when mixed. Dried isinglass is mixed with water, preferably in a blender or food processor, although a hand whisk will suffice. Finings should be prepared at least 24 hours before it is required. Also available is a new product, Brupaks Isinglass Paste. This paste must be mixed with citric acid and water before use.
FINING AND CLARIFYING PRODUCTS
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Brupaks supplies the following top quality finings and clarifiers.
Coarse Ground Irish Moss. The highest quality copper finings available. Recommended dosage 1 teaspoon per 25 litres (10g per hectolitre) of wort
Protafloc Copper Finings. An alternative to Irish Moss. Experimentation will determine which product works best for you.
Brupaks Dried Isinglass . Highly effective in the removal of excess yeast. Requires an electric blender for mixing. Recommended dosage 1 teaspoon in 500ml cold water (sufficient to clear 50 litres of beer).
Brupaks Isinglass Paste. Although not so easily stored as dried isinglass, this paste will keep for many months at room temperature. Dissolves more readily than dried isinglass but a blender is still recommended.
Brupaks Auxiliary Finings. The use of Brupaks Auxiliary Finings gives an overall improved beer fining performance. Advantages may include: a reduction in the amount of isinglass finings required; accelerated fining action; Improved polish on the final beer; reduced susceptibility to non-biological chill hazes.