Fining and Priming
Beer FiningsThis is the act of removing yeast and some other stuff from the fully fermented beer. Finings are usually added to the cask after the beer has been matured for a while, particularly if auxiliary finings have been used beforehand. It has to be said that most beers brewed with a good yeast will clear down without fining, given time. The main reason for fining is to speed up the clearing process or to deal with a difficult yeast. It is not normal to fine beers destined for bottling because the yeast needs to pack down firmly on the bottom of the bottle, whereas fined bottled beers tend to have loose, fluffy bottoms which makes the beer difficult to pour without disturbing the yeast and clouding the beer. Isinglass or gelatine can be used as a fining agent. Isinglass is the superior product, when fresh, and is the stuff that commercial breweries use. Unfortunately isinglass is not stable and has a poor shelf life, making it difficult for home brewers to use effectively.
Isinglass FiningsAnd so on to the vexing subject of isinglass. Many things have improved within the home brewing hobby during the twenty-five years or so that I have been writing about the subject, but regretfully Isinglass finings is not one of them. Many home brewers have problems with Isinglass; the ready-for-use liquid stuff is often in bad condition when purchased, and there is no way that the powder and floc forms of isinglass will dissolve properly using the instructions usually given with them. This is due, in part, to the appalling lack of technical brewing knowledge endemic in the home-brewing industry coupled with the persistent desire to make things appear to be easier than they really are. It seems that the vendors of some products have never tried using them as per their own instructions; alternatively they are knowingly "pulling a fast one". This makes it difficult to trust the quality of isinglass supplied by the trade, particularly liquid isinglass, and outright folly to trust the instructions accompanying some isinglass fining products.
Isinglass is made from the gas bladder of certain tropical fish, often of the sturgeon variety, although several species are suitable. The gas bladder, sometimes known as the swim bladder, is basically its adjustable buoyancy tank. Isinglass is added during maturation in cask to assist in dragging yeast out of suspension thereby improving clarity. Isinglass is another charge-based fining system, only this time it has a positive charge which attracts negatively charged particles, mostly yeast. It is the only stuff that commercial brewers use. However, in home-brewing the use of isinglass is complicated by various issues; the major being poor shelf life and highly optimistic instructions almost to the point of witchcraft.
Ready-for-use isinglass; that is the liquid stuff, has a shelf life of only four to eight weeks, and only then if the temperature has been maintained below 15°C. At temperatures above 20°C it rapidly denatures becoming ineffective as a result. It takes a considerable act of faith to trust the ready-for-use finings from the home-brewing supply chain, because there is no guarantee that the stringent storage (and transport) conditions have been met. Indeed I have seen isinglass stacked on open shelves at ambient temperature. It is a sad fact that many home brewers have attempted to fine with isinglass that is denatured and therefore knackered. Isinglass in good condition is an extremely effective fining agent, but due to the uncertainties surrounding ready-for-use liquid isinglass it is becoming increasingly common for home brewers to make up their own finings from powders or paste. However, even this is not necessarily a trivial task.
Isinglass FlocIsinglass is available as powders and flocs which are intended to be made up into ready-for-use finings. Flocs appear as large flakes and are available on the home-brewing marketplace. Generally speaking, however, these are not as easy to get into solution as the instructions indicate; they take a lot more time than professed and require either a food processor or hand-held stick blender. The time it takes to get this stuff into solution is directly proportional to the efficiency, or sheer strength, of the blender. Instructions tend to ignore the importance of standing periods. Standing periods are just as important to get the flocs hydrolysed as the mechanical blending action itself. A variable-speed food processor has the advantage that it can be left chugging away at low speed unattended. A stick blender, of the type that has a bell-shaped business end, has the disadvantage that you need to be with it to hold the button down, at least with mine I do, but it is a much more efficient style of mixer than the others. Whisk-type mixers are not very efficient at this sort of thing, but better than nothing.
Flocs are usually mixed at 6 grammes per litre with low alkalinity water. Deionised water or low alkalinity bottled water can be used. However, you can prepare your own low alkalinity water by boiling tap water for twenty minutes in a saucepan and racking the water off the chalk precipitate when cool. Chill the water to about 12°C in the fridge. The whole solution should be between 12°C and 16°C when mixing. It is probably best to make up this type of finings five or more days in advance; in fact start to make it up while the beer it is intended for is fermenting.
To make 500 millilitres of finings from floc: take 200 millilitres of chilled, treated water and add it to your mixing vessel. Keep the remainder of the treated water chilled for later use. Slowly add 3 grammes of floc to the water while the mixer is running. Mix for about ten minutes until the isinglass is uniformly dispersed. Leave to stand at a temperature between 12°C and 16°C for twelve to twenty-four hours for the isinglass to hydrate. After the primary mix and standing period comes the real business of getting the stuff to properly dissolve. This may require some serious mixing (and several days) depending upon how good your mixer is. At this stage you mix for as long as it takes for the mixture to look fully homogenised. If you have a variable-speed food processor, after an initial high-speed blitz, leaving it running at low speed for an hour works well. Modern hand-held blenders are very efficient; short bursts every fifteen minutes or so will suffice. Once your mixture appears to be fully homogenised, top up your solution to 500 millilitres with the chilled water, and give it another blitz to mix thoroughly. Stand for another twenty-four hours. Every twenty-four hours examine the finings and if not properly dissolved, as indicated by flocs forming on the bottom of the vessel, give them another few minutes blending and stand for a further twenty-four hours. Repeat this until you have got as much dissolved as you are likely to. This can take up to three days.
There will inevitably be some bits on the bottom of the mixing vessel, depending upon the purity of the isinglass, but you have gone as far as you can when you appear to be making no progress, or four days have elapsed from starting to make the stuff, whichever is the longer.
Maintaining the mixture between the recommended temperatures of 12°C and 16°C during the mixing operation is a tough one; the fridge is too cold and ambient too warm. However, that is the official recommended range. In practice ensuring that the solution does not exceed 16°C is probably good enough. Many home brewers, including myself, have performed the standing period in the refrigerator, well below 12°C, without observing any detrimental effects. It is quite possible to go and do a days' work without having to worry about the temperature of your finings. During the mixing process, in an emergency, adding a bit of the chilled water to lower the temperature is fine, although be careful not to exceed your final volume. Modern blenders, although very efficient, because of their high sheer strength do generate heat and raise the temperature of the solution, so be careful.
Once your isinglass is mixed, you can store it in the refrigerator, at normal refrigerator temperature, in a sealed container until ready for use. Do not allow it to freeze. When stored under these conditions it will have a shelf life of up to two months.
Isinglass PasteIsinglass paste is another way for the home brewer to make up ready-for-use finings, but it is still quite difficult and requires preparation some time in advance. It also requires a high-speed stick blender or food processor to facilitate mixing. Isinglass paste is used at 36 grammes per litre + 3.6 grammes citric acid per litre. The citric acid is usually supplied with the paste.
To make up half-a-litre of finings take a 500 millilitres of boiled and cooled or deionised water and chill to 12°C. The temperature of the make-up water should be between 12°C and 16°C during the mixing period. Care should be taken to ensure that the temperature does not exceed 16°C. Put 250 millilitres of the chilled water into your mixing vessel, start the mixer and add 18 grammes of isinglass paste. Keep mixing until the paste has dispersed. Add 1.8 grammes of citric acid and continue mixing until the paste has dissolved. This can take anything up to three hours, but with a high-speed food processor or high-shear hand-held blender it will take about fifteen minutes.
When you are sure that the paste has dissolved, top up to the final volume of one litre using the water already prepared, and then mix for a further fifteen minutes. The finings are now ready and should be stored below 16°C until ready for use. Do not freeze. There is no real need to blend continuously for long periods of time, particularly with a hand-held blender with which you have to stand holding the button down, but instead a series of short bursts followed by periods of standing will achieve much the same thing. The standing periods are as much an aid to dissolution as the blending itself.
Pre-Hydrolysed Isinglass PowderIf you have purchased a powdered isinglass and the word "hydrolysed" is written on the packaging somewhere, then you have a relatively easy time ahead of you. This isinglass has been pre-hydrolysed and freeze-dried, and is the closest you will get to instant finings, apart from the ready-for-use liquid. This is usually used at 6 grammes per litre. Use water of low alkalinity to mix with. This can be achieved by boiling the water in a saucepan for fifteen to twenty minutes, then racking off the chalk sediment when cool. Allow sufficient time for all of the chalk to settle out before racking the water off the sediment. Alternatively use deionised water. Cool the water to below 16°C before use.
Add the powder to your water, 3 grammes for 500 millilitres, mix for two minutes with a blender. Allow it to stand for twenty minutes, and then give it another two minutes' blitz with the blender. It is then ready for use. It is probably better to make up the finings a day or two in advance and give it another blitz with the blender after twenty-four hours, although, allegedly, this is not necessary with this type of product.
Harris Beer Brite is a pre-hydrolysed powder, and you can more or less trust the instructions on the packet. Beer Brite contains ingredients other than isinglass, including silica hydrogel which absorbs chill-haze-causing proteins. You will need to use the whole packet for a 23 litre batch of beer.
Copyright (C) Graham Wheeler 2009