GB2028340A - Finings for beer - Google Patents

Abstract

Finings for beer comprise gelatin and/or fish-glue fixed to a carrier material in a manner such that it or they will not dissolve in the beer. The carrier may be albumen, cellulose or diatomite, and the gelatin and/or fish-glue may be adsorbed or covalently bonded to the carrier.

Description

SPECIFICATION Finings for beer The invention relates to finings for beer using gelatin and/or fish glue.

In the production of beer, an important operating process is its storage after completed main fermen tation until it is bottled. It is during this stage that various processes are to take place in the beer. The residual extract that remains unfermented during the main fermentation is to be fermented as far as is possible. The beer is to be enriched with carbon dioxide gas. Ataste maturing process is to take place. The influence of the cold during storage is to render albumen tannin compounds which are instable to cold insoluble and separate them out. Substances causing clouding and micro-organisms in the beer are to separate from the beer so that a substantially preclarified beer is subsequently subjected to filtration.

According to recent discoveries, the three firstmentioned reactions are not necessarily bound to the storage cellar. In many breweries it is conventional to bring about final fermentation of the beer for example already in the fermentation cellar. Taste maturing is anticipated with more or less success for example by selecting the fermentation temperature.

Enrichment with carbon dioxide may be postponed until just before filtration or bottling of the beer in that the carbon dioxide obtained during the fermentation process is returned to the beer.

This leaves albumen stabilization through the influence of cold and clarification of the beer as the most important function during the storage phase.

Albumen stabilization itself can be achieved by adsorption agents which are brought into contact with the beer during final filtration, for example in the form of finely pulverulent silica gel products. Of course the effectiveness of such adsorption agents and in fact the entire stabilization process can be carried out more economically and to last longer if a certain amount of prestabilization has already taken place in the storage cellar, e.g. under the influence of cold. However, where this is not so, one can compensate by an increase in adsorption agents or other chemicals which improve the stability of the beer.

Accordingly, the most important remaining object of the storage process is the natural clarification of the beer.

The natural clarification of the beer in the storage cellar is particularly important to a brewer because it determines the smooth sequence of the filtration process on the one hand and the costs to be expended for this purpose on the other hand. In modern considerably rationalized breweries, it is important that each of the various method steps in beer production should take place smoothly and with the same output with which brewing is initially started. For this reason a brewery experiences considerable difficulties if for some reason the expected output of filtration is not achieved.Further, with poorly clarified beers the filtration costs can rise very markedly, namely through an increased consumption of filtering aids, through higher labour costs and finally also through the possible need for having additional filters or separators available for emergencies.

Modern brewing technology by no means meets this need for clarifying the beer. On the contrary, it produces problems. On the one hand, the cause is the reduced storage periods which of course no longer permit substantial clarification through natural sedimentation of the clouding materials.

However, on the other hand depositing of these materials causing turbidity is made more difficult in fermentation vessels of large volume, primarily in upright cylindroconical tanks up to 20 m in height.

Good preclarification of the beer is of particular importance in the Federal Republic of Germany and other countries which only permit the use of adsorption agents for the stabilization of beer. This is because the most common adsorption agents for the adsorption of albumen from the beer are very fine powders which, because of their small particle size alone, already reduce the filtering throughput of the diatomite filter. If, in addition, poorly clarified beer is subjected to filtration, very severe difficulties are produced by a reduced filtering throughput with possibly incomplete stabilization effect.

This problem has been observed frequently in recent years and has led to grave operating disruptions in many breweries. Malts were used resulting in green beer which is unstable to cold and clarifies poorly. Having regard to the stability to refrigeration expected by the customer, one was forced to increase the use of adsorption agents during final filtration. This still further reduced the throughput of filtration which was already lower because of poor beer clarification.

The problem of natural clarification of the beer in the storage cellar has been known for a long time.

Means are also known for accelerating this clarification (Weinfurtner F: 'Die Bierbrauerei', Volume III, 'Die Technologie der Gärung', Das fertige Bier', 1963, published byVerlag Enke, Stuttgart, page 228; De Clerck J.: 'Lehrbuch derBrauerei',Volume 1,1964, published by Versuchs- und Lehranstalt für Brauerei in Berlin, page 664). Glue-like finings are conventional which may be of animal or vegetable origin.

The best known is isinglass, also termed fish-glue, the effectiveness of which according to De Clerck is based on its content of gelatin of about 77%. However, gelatins or glues of vegetable origin have also been employed as agents for accelerating the clarification of beer.

Of the known glue-like finings, only isinglass may be used in the Federal Republic of Germany, and even then only for top fermentation beer. For bottom fermentation beer, which constitutes the principal amount of beer output in the Federal Republic of Germany and in which preclarification is of particular importance for the aforementioned reasons, none of the known glue-like finings may be employed.

Even if the known glue-like finings were permiss ible for bottom fermentation beer, they wou Id only enable a good filtering throughput to be achieved and thereby give the brewer more scope when using pulverulent adsorption agent during settling filtra tion. They would not be suitable for simultaneous albumen stabilization.

It has also already been suggested to conduct the albumen stabilization of beer, which is usually car ried out with pulverulent adsorption agents during the final settling filtration, in two stabilization phases by already adding some of the adsorption agent in the storage cellar. Here the adsorption agent has sufficient time to take effect and can separate out again through sedimentation on the base of the tank dur ing storage. However, this method is not successful in all cases because the pulverulent adsorption agents are not always capable of binding the very finest turbid particles of the beer and drag them along to the base of the tank.

Consequently, one achieves a certain amount of stabilization but no marked improvement in the clarity and the filtering throughput. It has even been observed that for beers in a particular form the sedimentation is retarded, especially sedimentation of the very finest particles of adsorption agent. This then leads to such a beer being even more difficult to filter than an untreated beer. It has not yet been possible to acquire reliable knowledge about the reasons for the stated observations.

In relation to the state of the art, therefore, it remained to solve the problem of finding finings which accelerate the natural clarification of the beer, improve its filtering behaviour and also unreservedly fulfil the purity regulations, namely have an adsorbing effect, impart no soluble substances to the beer and change neither the taste nor the smell of the beer.

The solution of the stated problem in finings for beer using gelatin and/or fish-glue resides according to the invention in that the gelatin and/or the fishglue is so fixed on a carrier material that they or it are or is insoluble in beer. In addition to solving the stated problem, the finings according to the invention have the advantage that they also increase the albumen stability of the beer at the same time and are substantially free from water-soluble substances, i.e. they meet the regulations of the purity laws.

It is surprising that the adsorption agents conventional for the albumen stabilization of beer are capable of quantitatively adsorbing gelatin and/or fishglue if the limits of saturation have not been exceeded, and to retain them irreversibly so that none of the adsorbed gelatin and/or the adsorbed fish-glue is imparted to the beer, whereby the new findings meet the regulations of the purity laws. It is even more surprising that the glue-like finings, gelatin and/or fish-glue, bonded to an adsorption agent improve the clarity and filtering properties of the beer even in this bonded condition. In the prior art, the clarifying effect of these agents resides in their swelling and solution in water.However, it was also unpredictablethatthe adsorption agents used as carriers retain their albumen stabilizing effect despite being partially charged with gelatin and/or fish-glue.

The beerfinings according to the invention thus solve the aforementioned problem in the brewing industry, namely ensuring that clarification, improvement of the filtering properties and albumen stabilization of the beer are simultaneously obtained by means of one and the same substance which conforms with the purity regulations. The finings according to the invention are preferably used in the storage tank. However, they can also be used at the filter.

Agents known for the albumen stabilization of beer are suitable as adsorption agents in the sense of the invention, e.g. finely pulverulent silicic acid xerogels, finely puverulent silicic acid hydrogels, finely pulverulent precipitated silicic acids in a moist or dried condition, bentonite, acid-activated fuller's earth in a moist or dried condition, other natural or synthetic silicates having adsorption properties, as well as activated carbons and of course mixtures of the stated substances.

The gelatin used as finings according to the invention must of course have a purity meeting the requirements based on edible gelatin. One may use gelatin of the so-called B type, i.e. basically pretreated. However, better results are generally achieved with gelatin of the so-called A type, i.e. acid pretreated gelatin. The gelatin content offinings according to the invention naturally primarily depends on the adsorption capacity of the available adsorption agent for the gelatin in question. Advantageously, it should not be above 10%, preferably below 5%, of the dry substance of the adsorption agent.

Isinglass or fish-glue is employed in a manner analogous to gelatin. Again, the content should not be above 10% related to the dry substance of the adsorption agent.

However, the limit of the amount of gelatin and/or fish-glue employed is generally very simply obtained by the adsorption capacity of the adsorption agent used as carrier material. If one employs more than the albumen stabilizing adsorption agent can adsorb, then it will not be able to adsorb the entire amount. One then obtains an adsorption agent which does not meet purity requirements because the excess gelatin and/or fish-glue remains soluble in water and thus also in been In a further development of the invention, the gelatin and/or the fish-glue is chemically cross-linked on the adsorption agent. This further development of the invention also permits not only adsorption agents but also other inert carrier materials, e.g. cellulose or diatomite to be employed as a carrier material for the gelatin and/or the fish glue. The chemical cross-linking also ensures under unusual conditions of use that the gelatin and/or the fish-glue when coming into contact with the beer cannot be dissolved off the carrier material, preferably the adsorption agent, again.

However, the subject of the invention is also finings for beer using gelatin and/or fish-glue as a commercial product which is characterised in that it consists of a finely pulverulent mixture of gelatin and/or fish-glue and an albumen stabilizing adsoprtion agent known per se on which the gelatin and/or fish-glue is fixable. The beer finings according to the invention are made and marketed in this form. Fixing of the gelatin and/or fish-glue on the adsorption agent is only carried out in the brewery by suspend ing the mixture in water.

The production of finings according to the invention for beer is simple. The following methods are suitable.

In a first embodiment, the method of making finings for beer using gelatin and/or fish-glue is characterised in that a suspension of a pulverulent albumen stabilizing adsorption agent is brought in contact with a solution of gelatin and/or fish-glue and left to stand for some time with occasional stirring.

During the course of a maximum of 1/4 hour, the gelatin and/or fish-glue is quantitatively and irreversibly bonded to the adsorption agent if it was not added in excess.

To check whether this was actually the case, the following test is employed. After the contacting period, the suspension is centrifuged. 1 ml of 50 /O sulphuric acid as well as 1 ml of a solution of 50 g sodium molybdate in 100 ml H2O are added to 10 ml of clear product of centrifuging. The presence of gelatin and/or fish-glue to an excess amount results in clouding. The detection limit of this test is at 2 mg gelatin in 100 ml water.

Another variation resides in mixing finely pulverulent gelatin and/or finely pulverulent fish-glue with finely pulverulent adsorption agent and possible again subjecting the mixture to very fine grinding for additional homogenization.

In a second embodiment of the invention, the method of making finings for beer using gelatin and/or fish-glue is characterised in that the gelatin and/or fish-glue is worked into the albumen stabilizing adsorption agent during production of the latter.

Thus, the gelatin and/or fish-glue in the form of a concentrated solution or also as a powder can be worked into silicic acid hydrogel or acid activated washed and not yet dried fuller's earth, preferably by a kneader and the mixed product then subjected to drying and grinding.

Finally, in certain cases, namely if the selected albumen stabilizing adsorption agent does not irreversibly bind the selected gelatin and/or fishglue, it may become necessary to cross-link the gelatin and/or fish-glue on the carrier material chemically. Naturally, other known methods of hardening gelatin may be employed within the scope of this inventive concept.

The following examples demonstrates the production, use and function of the finings according to the invention, gelatin having been used as the glue-like finings. When employing fish-glue, the procedure is analogous to these examples.

Example 1 Determining the maximum amount of gelatin. 10 g of finely ground silicic acid xerogel are dispensed into each of several 100 ml vibratory cylinders. One adds about 50 ml water and suspends the silica gel therein. Increasing amounts of a 2% gelatin solution in water are then added so that 50, 100, 200, 300, 400, 600, 800 mg of gelatin are added to the 10 g of silica gel that was weighed in. Water is added to arrive at 100 ml of liquid, vibration is performed and leaves the product to stand for hour with occasional stirring. About 30 ml of the suspension are then centrifuged and the clear product of centrifuging is tested for unadsorbed silica gel by means of the previously described test.

Result: 10 g silica gel + 0 mg gelatin negative 10 g silica gel + 100 mg gelatin negative 10 g silica gel + 200 mg gelatin negative 10 g silica gel + 300 mg gelatin negative 10 g silica gel + 400 mg gelatin negative 10 g silica gel + 600 mg gelatin positive 10 g silica gel + 800 mg gelatin positive The test shows that the silica gel adsorbs up to 4% gelatin irreversibly.

The adsorption capacity of other possible adsorbents is determined in a similar manner.

How much gelatin is necessary for treating a certain beer varies from case to case and can be determined by fining and stabilizing tests (see the later examples). There is a tendency for the fining effect of the combined adsorption agent to improve as more gelatin is employed in relation to the carrier adsorbent. The albumen stabilizing effect of the carrier product will then drop slightly.

Example 2 During testing on a small scale, the use of silicic acid xerogel with 2% gelatin has proved to be an optimum for the clarification and simultaneous albumen stabilization of a particular beer. For the treatment of beer in the brewery, one suspends the required amount of diatomite in water. The amount of gelatin accounting for 2% of the weight of silica gel is dissolved in hot water and this solution is then added to the silica gel suspension. After 1/4 of an hour, the sediment can be employed for the treatment of beer.

Example 3 98 kg of a finely pulverulent dry acid activated fuller's earth according to DOS 2 247 530 are intimately mixed with 2 kg of very finely ground edible gelatin having a particle size below 100 mesh. This mixture can be suspended in water without difficulties. The gelatine is thereby easily dissolved and is immediately adsorbed by the fuller's earth.

Example 4 98 parts by weight of a granular silicic acid xerogel are mixed with 2 parts by weight of coarsely ground gelatin. This mixture is ground to a very fine powder with the aid of a fast pin mill. This very fine powder is likewise suspended in water without difficulties, the gelatin becoming dissolved and immediately adsorptively retained on the silica gel.

Example 5 Use is made of acid activated fuller's earth according to DOS 1 642 767 as obtained from the filter press after washing. In this condition the filtered product contains 33% of dry matter. 300 kg of this filtered product (corresponding to 100 kg of dry matter) are intimately mixed in a kneader with a solution of 2kg edible gelatin in 10 litres of hot water. This is fol lowed by drying and grinding in conventional man ner to form a fine powder.

Example 6 500 g of a silicic acid hydrogel with 40% of dry matter are suspended in 2 litres of water. 5 g of gela tin dissolved in 100 ml of water are added. After leav ing to stand for 15 minutes with occasional stirring, 20 ml of 35% formalin solution are added. The sedi ment is kept in a closed vessel for 16 hours at 800C.

The hydrogel is then sucked off, washed with water, subsequently dried at 100"C and finely ground.

A similar sediment is produced by adding 20 ml of a 25% glutaraldehyde solution instead of the formaldehyde. With the products here stated, the gelatin was cross-linked on the adsorption agent and thereby made additionally insoluble. The amount of gelatin on the silica gel dry substance was here 2.5%.

Example 7 Fining effect of the products according to the invention. Use was made of: a finely pulverulent silicic acid xerogel with 2% gelatin made in accordance with Example4 and, as a comparison, the same xerogel without gelatin. Similarly, a finely pulverulent dry fuller's earth according to DOS 2 247 530 with 2% gelatin is employed when made analogously to Example 4, and also without gelatin.

The fining effect of gelatin alone is also observed. 20 mg per litre of beer are used in the form of a 1% aqueous solution.

Before being used, the adsorbents are stirred with water to form a 10% suspension. Freshly barrelled lager beer from a Munich brewery is filled from the storage cellar into 1 litre beer bottles. 50 g/hl of the adsorption agent according to the invention are added to this beer in the form of an aqueous suspension or 2 ml of the 1% gelatin solution. In the case of t gelatin alone, therefore, twice as much gelatin is used per litre of beer than with the adsorbents according to the invention. The beers are now stored at 0 C. Progressive fining is observed in the turbidity meter. The result is given in the following Table.

Turbidity after days (EBC units) 1 3 5 7 O-beer *15 > 15 o15 > 15 silica gel without gelatin o15 > 15 o15 > 15 silica gel with 2% gelatin > 15 > 15 7.5 6.0 fuller's earth 15 15 o15 > 15 fuller's earth with 2% gelatin o15 > 15 8.1 6.4 gelatin *15 o15 > 15 about 12 It will be seen from the foregoing table that during 7 days of storage of the sample beers, the O-beer became somewhat clearer but after 7 days the tur bidity still amounted to more than 15 EBC units and was not precisely determinable in the measuring device.The same applies to Sample 2 which contained 50 g/hl silicic acid xerogel and also to Sample 4 with 50 g/hl fuller's earth.

In contrast, a very marked acceleration of clarification is shown for Sample 3. Even after 3 days this sample was very clearly different from the O-beer.

After 5 and 7 days, considerable clarification had already occurred. Similar results were also obtained with Sample 5 for which fuller's earth with 2% gelatin was used. The gelatin alone accelerates fining to a slight extent.

Example 8 After 7 days of observing the clarification, the foregoing samples were also subjected to filtration under laboratory conditions. Use was made of a method which is described in 'Monatsschriftfr Brauerei' (No. 21, pages 277 to 285, 1968) and which permits the filterability of a beer to be expressed in exact numerals. The filter cake factorwas deter mined. The higher this factor, the slower is the filtra tion. The six sample beers gave the following results: Filter Cake Factor O-beer 0.340 silica gel without gelatin 0.374 silica gel with 2% gelatin 0.284 fuller's earth 0.452 fuller's earth with 2% gelatin 0.305 gelatin 0.350 The foregoing result shows that the 0 - beer has a filter cake factor of 0.340.In Sample 2 with the finely pulverulent silica gel, one obtains an increase of this filter cake factor by about 10%. Filtration is thus somewhat retarded in this case. In contrast, Sample 3 according to the invention exhibits a reduction of the filter cake factor in the order of 20%. Sample 4 with very finely ground fuller's earth takes considerably longer to filter than 0 - beer; the filter cake factor rose to 0.452. On the other hand, Sample 5 was clearly much better to filter than 0 - beer. The sample with gelatin had substantially the same filtration behaviour as did the 0 - beer.

Example 9 The sample beers filtered in the preceding example were collected in a carbon dioxide atmosphere and subjected to the forcing test. After a storage period of 3 days at 40"C and 24 hours in melting ice, the increase in cold turbidity was as follows: Cold Clouding after3 Warm days EBC Units O-beer 8.1 silica gel without gelatin 3.1 silica gel with 2% gelatin 2.9 fuller's earth 2.1 fuller's earth with 2% gelatin 2.4 gelatin 7.5 These results show that the adsorbents according to the invention had about the same albumen stabilizing effect as did the untreated materials without gelatin. It will be seen that Sample 3 was somewhat stabler than Sample 2. The reverse is found when comparing Samples 4 and 5. However, the differences are slight.Sample 6, for which gelatin was used alone, had only a slightly better stability than did the 0 - beer.

The beers of Samples 1,2 and 3, i.e. the 0 - beer, the beer treated with silica gel and the beer treated with the product according to the invention consisting of silica gel and gelatin, are also tested to see whether gelatin was dissolved in the beer.

For this purpose samples of the three beers are first hydrolyzed with acid and then examined for hydroxyprolin. This amino acid is a substantial component of the gelatin. It is found that in all three beers there is no difference in hydroxyprolin and this means that no gelatin was dissolved off the product according to the invention during contact with the beer. This confirms the aforementioned finding according to which silica gel and also fuller's earth take up a certain amount of gelatin, up to about 5%, and irreversibly retain it by adsorption. This irreversible adsorption is also ensured under the external conditions of the beer (pH, ion strength etc.), so that the silica gel or fuller's earth product according to the invention with gelatin fulfils the requirements of the purity regulations.

Claims (9)

1. Finings for beer using gelatin and/or fish-glue, characterised in that the gelatin and/or the fish-glue is so fixed on a carrier material that they or it are or is insoluble in beer.

2. Finings according to claim 1, characterised in that the gelatin and/or the fish-glue is adsorptively fixed on an albumen stabilizing adsorption agent known per se.

3. Finings according to claim 1, characterised in that the gelatin and/or the fish-glue is fixed by chemical cross-linking on an inert carrier material, e.g. cellulose or diatomite.

4. Finings for beer using gelatin and/or fish-glue, characterised in that it consists of a finely pulverulent mixture of gelatin and/or fish-glue with an albumen stabilizing adsorption agent known per se on which the gelatin and/or fish-glue is fixable.

5. A method of making finings according to claim 1, characterised in that a suspension of a pulverulent albumen stabilizing absorption agent is brought in contact with a solution of gelatin and/or fish-glue and left to stand for some time with occasional stirring.

6. A method of making finings according to claim 1, characterised in that dry and ground gelatin and/or dry and ground fish-glue is mixed with a ground adsorption agent, the mixture is stirred to form a suspension and left to stand for some time.

7. A method of making finings according to claim 1, characterised in that gelatin and/or the fish-glue is worked into the albumen stabilizing adsorption agent during production of the latter.

8. A method of making finings according to claim 2, characterised in that the gelatin and/or the fishglue is chemically linked on the carrier material.

9. A method of making finings according to claims 2 and 7, characterised in that the gelatin and/orthe fish-glue is chemically linked on the carrier material with formaldehyde or glutaraldehyde.