PROCEDURE FOR PREPARING BREWERY RAW MATERIAL, BREWERY RAW MATERIAL PREPARED BY THE PROCEDURE, AND USE OF THE BREWERY RAW MATERIAL

Abstract: A procedure for preparing brewery raw material from barley. The barley is ground in dry state, from the ground barley a fine fraction is separated by sifting which contains starch in abundance, and little fat, protein, polyphenol and beta -glucan, and its particle size being 150 to 300 mu m, for use as brewery raw material together with malt.

Description: PROCEDURE FOR PREPARING BREWERY RAW MATERIAL, BREWERY RAW MATERIAL PREPARED BY THE PROCEDURE, AND USE OF THE BREWERY RAW MATERIAL The present invention concerns a procedure for preparing brewery raw material, a brewery raw material prepared by said procedure, and the use of said brewery raw material in beer-making. Beer is mainly made of barley malt. The price of malt is comparatively high, however, and therefore endeavours are in beer-making to adopt less expensive raw materials, e.g. the use of starch and of raw mate¬ rials rich in starch, on the side of malt. Beers with lighter flavour have enjoyed in- creasing popularity in recent years. In the making of lighter beers raw materials rich in starch are used on the side of malt. Regarding the technology known in the art, the following references are cited: Lebensmittel- industrie. Vol. 27, 1980, p. 124-126, Tschiersch, R. , Einige Aspekte und Probleme der Zerkleinerung von Ger- stenrohfrucht, and Brewer's Guardian, July 1985, p. 18- 21, Hudson, J.F., Adjuncts and their use in brewing. Brewery raw material rich in starch has here¬ tofore been prepared e.g. of barley by a wet process in which the starch has been separated for use, on the side of malt, in beer-making. These separation proces¬ ses of prior art are not fully satisfactory however, especially owing to their complexity and cost. The object of the present invention is to dis- close a novel procedure for preparing from barley a brewery raw material for use on the side of malt, said procedure being implementable in a simple and flexible way in conjunction with other barley processing. It is particularly an object of the invention, to disclose a procedure in which brewery raw material can be prepared at lower cost than before and in such manner that it becomes possible with the brewery raw material in ques- tion to replace a great part of the malt, up to half thereof. . Regarding the features characterizing the in¬ vention, reference is made to the Claims section. The invention is based on the unexpected fact observed in studies that were made, that the fine frac¬ tion separated by sifting from barley after grinding, and which is rich in starch, is appropriate as it is to be used as brewery raw material, together with malt. It is possible to use this brewery raw material in any small proportion of the total malt quantity, advan¬ tageously more than 10% by weight up to 15, suitably 40, advantageously 45, most advantageously even up to 50% of the aggregate of malt and brewery raw material. This means, in practice, that up to half of the malt can be replaced with brewery raw material prepared as taught by the invention. This naturally implies lower manufacturing costs than before for the part of the brewery raw material, in other words, lower production cost. Moreover, the brewery raw material of the inven¬ tion is particularly well suited for making light beer, i.e., no such amounts of fat, proteins, polyphenol and β-glucan are dissolved in the mash and worts from the brewery raw material of the invention as from conven- tional barley or barley malt. Thereby the beer that is being made will have a light and mild flavour, consist¬ ent with accustomed modern taste. As taught by the invention, from ground barley a coarse fraction and a fine fraction are separated by sifting, the latter having particle size less than 300 μm, advantageously less than 250 μm, e.g. 150 to 300 μm, advantageously 150 to 250 μm. The fine fraction contains starch in abundance, and little fat, protein, polyphenol and β-glucan. The fine fraction is ready to be used for brewery raw material as it is, together with malt. The other malt constituents, i.e., the coarse fraction obtained on separation and which con- tains e.g. bran and grain hull parts, and other con¬ stituents potentially to be separated, can be used for raw materials in other processes. The manufacturing process is a dry process: grinding and separation are carried out in the dry state, at a moisture content such as is employed in conventional milling industry. According to the invention, the proportion of the fine fraction to be produced, referred to the bar¬ ley quantity that has to be ground, is 10 to 25% by weight, advantageously 10 to 20% by weight, of the total barley quantity. The fine fraction contains more than 65% by weight, suitably more than 75% by weight, advantageously even more than 80% by weight starch, while the normal starch content of barley is about 55 to 60% by weight. - In this description all percent¬ ages are given as per cent by weight, calculated on the dry matter. The procedure of the invention enables brewery raw material to be prepared by means of a simple grind- ing process, followed by sifting out the desired frac¬ tion. The grinding process can, for instance, be imple¬ mented with a hammer mill, which is commonly employed in the mill industry. The sifting can be carried out using, for instance, a plan sifter, advantageously one having a cylindrical, rotating screen, in which case the centrifugal effect can also be utilized in the sep¬ arating process. When the barley is ground in two steps, the screen size of the sieve in the first sepa¬ rating step is, for instance, on the order of about 250 to 300 μm, by which the coarsest particles will be separated. In the second sifting step the screen size is on the order of 150 to 250 μm, whereby the desired fraction with high starch content will be separated. The invention is described in the following in detail, with the aid of embodiment examples, referring to the attached drawing, wherein:- Fig. 1 presents the block diagram of a process accord- ing to the invention, in simplified form. Fig. 2 presents the flow chart of another process according to the invention, and Fig. 3 presents filtration curves when brewery raw ma- terial according to the invention is being applied. In Fig. 1, the barley 1 going to be fed into the process is ground in a hammer mill 2 to barley grits; the grits contain about 50% by weight starch. The grits 3 are conducted to a sifter 4; the passing fraction 5 about 15% of the barley is conducted to con¬ ventional continued barley flour refining. The coarser fraction 6 is conducted to a separator 7, where the coarser parts 8 are separated, about 4% of the barley to be conducted further to a sifter 9, where the bran 10 is separated; the coarser flour 11 is conducted to a conventional continued barley flour process. The finer barley flour 12 obtained from the separator 7,, starch content about 65% by weight, is conducted to the sec¬ ond grinding step, i.e., to a hammer mill 13, the flour 14 thus obtained is sifted in a sifter 15; the ' coarse flour 16 thus obtained is conducted to the conventional barley flour process. The fine fraction thus obtained, containing about 75 to 80% by weight starch, is sepa¬ rated for use as brewery raw material together with malt. The proportion of fine fraction of the total bar¬ ley quantity introduced, 1, is about 10 to 25% by weight. The particle size of the fine fraction is less than 250 μm. The separating process is depicted in detail in Fig. 2. The barley flour obtained from the hammer mill 13, i.e., from the hammer mill of the second grinding step, is conducted to a Typhoon sifter 15 , the coarse fraction 16. ^ to an exit silo 17, the fine fracti¬ on to a second Typhoon sifter 15 2 . From here, the coarse fraction 16, is carried to the exit silo 17 and the fine fraction to a silo 18, to be transported to the brewery; the fine fraction has particle size smaller than 250 μm. The feed to the sifter 15 1 is 5 to 8 t/h, the feed from sifter 15. ^ to the exit silo 17, 4 to 7 t/h, and the removal from sifter 15 2 in the form of fine fraction to the storage silo 18, 1 t/h. Table 1 gives the composition of the brewery raw material prepared by the process of Fig. 1, com¬ pared with conventional barley flour and with barley starch. The brewery raw material was obtained by fur¬ ther fractionating, as taught by the invention, the flour fraction obtained in the dry grinding process and already classified. The yield of fraction enriched in starch was 10 to 15% by weight of the total flour flow quantity. Table 1. The particle size of the concentrate was less than 0.16 mm. According to the results, solubility and extractibility of the flour fraction were good; the use of the brewery raw material on the side of malt in beer-making implies no separate raw cereal boiling. Furthermore, liquefaction and saccharifying can be im- plemented under identical conditions (temperature, pH) as with barley malt. EXAMPLE 1 Experimental arrangements: In the experiments, two different barley dry grinding fractions were studied, Fraction I and Frac¬ tion II. Fraction I represented the reference fraction, and Fraction II represented a finely divided barley meal fraction according to the invention. The reference fraction I was prepared in a way differing from the procedure of the present invention, by mixing barley meal and barley starch (at 50/50 pro¬ portions; starch content was found to be 78.5% by weight) . The procedure by which Fraction I was prepared is costly and complicated. Preparation of Fraction II conforming to the invention was performed at production scale, by first grinding the barley in accordance with the process of Alko's Koskenkorva production unit in step I to granule size (less than 2 mm) . After grinding followed dust removal from the barley by sifting and removal of out¬ ermost husk parts by applying air classification. The ground barley granules were conducted to the grinding in step II, the barley powder emerging therefrom being subjected to classification according to the invention. As taught by the invention, the powder was conducted to a typhoon sieve having mesh size 300 μm. The passing fraction from this typhoon sieve was conducted to a second typhoon sieve, mesh size 200 μm. The finely divided flour fraction passing the second typhoon sieve was the desired brewery raw material according to the invention (Fraction II), which was rich in starch (starch content 82.8% of dry matter). " In order to illustrate the size distribution of Fraction II, a sieving carried out on Fraction II is here presented (Table 2). Table 2 also shows, for pur¬ poses of comparison, the results of a similar sieving made with barley flour. Table 2 Kustaa Pilsner malt (α-amylase activity 52 DU, and diastatic force 250 WK) was used for malt. 30% of the malt quantity were replaced with barley fraction. Mashing mix: 70 g Kustaa malt, grit coarseness 30 g barley fraction Grit/water proportion 1:1 (100 g : 300 ml) pH control, 0.6 ml 1-n sulphuric acid Calcium salts, 0.15 g CaCl 2 x 2H 2 0 Mashing programme. Test series 1 (6 speci¬ mens) , Fraction I: Mashing-in 45°C, Pause 0, 15, 30, 45, 60 or 75 min. Raising l°C/min 65°C, saccharifying pause 1 h Raising l°C/min 80°C, pause 10 min. Straining 80°C (through filter paper) Washing 80°C, 2x 100 ml water. Test series 2 (4 specimens). Fraction II: Mashing-in 48°C, pause 0, 30, 45 or 60 min, otherwise as in Test series 1. Test series 3 (3 specimens). Fractions I & II: Mashing-in 48°C, pause 30 min. otherwise as in Test series 1 Grit/water proportion 1:2.86 (70 g grits: 200 ml) . Results: In the first test series the effect of the length of the mashing-in period on cleaving of glucans was studied (Table 3). Table 3. Results of analysis of worts in test series 1 (Fraction I) . Pause 45°C min 0 15 30 45 60 75 Extract content % b.w. 17.1 18.0 17.1 17.9 17.5 17.9 Viscosity cP 2.82 2.70 2.57 2.48 2.42 2.44 β-glucans mg/1 1218 817 596 474 410 369 FAN mg/1 238 259 260 290 285 302 NLKA % 83.2 84.9 84.4 86.0 85.8 86.0 Filtration ml/3h 230 215 280 255 265 290 Turbidity FU 10 9.3 10 9.3 9.3 8.8 Extract yield % air-dry 42 42 52 49 50 56 FAN = Free amino nitrogen NLKA = Apparent final degree of fermentation The length of the mashing-in pause had a nota¬ ble effect on the viscosity of the wort, on the cleav- ing of β-glucans and on the free amino nitrogen quan¬ tity. Increasing the length of the pause beyond 45 min. caused no further increase of the quantity of ferment¬ able sugars, as measured in terms of final degree of fermentation. Determination of filtering rate by using filter paper is not very accurate. The filtering runs were terminated after 3 hrs. The extract yields have been calculated on the basis of volume at the end of filtration. Saccharification was measured by means of the iodine/starch test during the saccharifying pause at 65°C. No specimen had undergone complete sacchari¬ fication. In the second test series, the mashing-in temperature was raised to 48°C and the effect of frac¬ tion II on the wort quality was studied. The results from the test series are displayed in Table 4. Fraction II was rather more finely divided than fraction I, and this had its own influence on extraction, hydrolysis of β-glucans and lowering of wort viscosity. Filtration and extract yield were clearly better in this test ser¬ ies than in the preceding series. All specimens were completely saccharified by the time the temperature reached 80°C. Table 4. Results of analysis of worts in test series 2 (Fraction II) . Pause 48°C min 0 30 45 60 In the third test series the effect of frac¬ tions I and II on filtration was studied using a so- called Tepral filtering apparatus. The filtration curves are reproduced in Fig. 3. The mix in which 30% of the malt had been replaced with fraction II filtered best and yielded the highest extraction result. Frac¬ tion I was comparatively coarse, and therefore extrac¬ tion and hydrolysis of β-glucans could not proceed far enough during the 30-min. mashing-in pause. Moreover, its mash cake bound water, and the quantity of wort obtained was less than that obtained using fraction II. Table 5. Results of analysis of worts in test series 3. Summary: It is possible by lengthening the mashing-in pause, to exert a remarkable influence on the hydroly¬ sis of β-glucans and on the viscosity of the wort. The finely divided barley fraction (II) here examined was well appropriate to be used as raw material replacing malt. Mash filtration and extract yield were better than those in full malt mashing. The embodiment examples are meant to illus¬ trate the invention, without confining it in any way whatsoever. For instance, brewery raw material prepared as taught by the Invention can be used in beer-making by any process known in the art, the new brewery raw material being substituted for part of the malt.

Claims: CLAIMS 1. A procedure for preparing brewery raw ma¬ terial from barley, characterized in that the barley is ground in dry state, from the ground barley a fine fraction is separated by sifting which has particle size less than 300 μm and which contains more than 65% by weight starch, and little fat, protein, polyphenol and β-glucan, for use as brewery raw material together with malt. 2. Procedure according to claim 1, character¬ ized in that the particle size of the fine fraction is less than 250 μm. 3. Procedure according to claim 1 or 2, char- acterized in that the barley is ground in one step, the coarse fraction and bran being removed upon grinding and the fine fraction being recovered. 4. Procedure according to claim 1 or 2, char¬ acterized in that the barley is ground in two steps, the first step being a coarse grinding process, the coarse fraction and bran being removed after said first step and at least part of the finer powder being ground in the second step in a hammer mill, and that the fine fraction obtained from the hammer mill is recovered. 5. Procedure according to any one of claims 1-4, characterized in that the fine fraction consti¬ tutes 10 to 25% by weight, advantageously 10 to 20% by weight of the total barley quantity. 6. Procedure according to claim 5, character- ized in that the fine fraction contains starch more than 75% by weight, advantageously more than 80% by weight. 7. Brewery raw material prepared by a proce¬ dure according to any one of claims 1-5. 8. The use of brewery raw material prepared by a procedure according to any one of claims 1-6 to¬ gether with malt in beer making. 9. Use of brewery raw material according to claim 8, characterized in that more than 10% by weight brewery raw material is used, calculated on the aggre¬ gate quantity of malt and brewery raw material. 10. Use of brewery raw material according to claim 9, characterized in that 10 to 40% by weight brewery raw material, calculated on the malt quantity, is used. 11. Use of brewery raw material according to claim 9, characterized in that 10 to 50% by weight brewery raw material, calculated on the malt quantity, is used.

Inventors: KUIKKA KAARLO, LAEHDESMAEKI MATTI, KUIKKA, KAARLO, LAEHDESMAEKI, MATTI
Applicants: ALKO AB OY, OY ALKO AB
Application year: 1993
Main classification: C12C5
IPC codes: C12C1, C12C5, C12C7