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Title:
METHOD OF MAKING BEER
Document Type and Number:
WIPO Patent Application WO/2016/040967
Kind Code:
A1
Abstract:
A method of making beer that is less susceptible to becoming light-struck, includes the steps of: (i) exposing wort or beer to light within the wavelength range 200 to 700 nanometers to yield photolyzed wort/beer with 3-MBT; (ii) fermenting the photolyzed wort/beer to yield fermented photolyzed beer to reduce the levels of 3-MBT; (iii) exposing the fermented photolyzed beer to ultraviolet light within the wavelength range 122 to 299 nanometers to yield sterilized beer; and (iv) packaging the sterilized beer.

Inventors:
GROENVELD STEVEN CRAIG (ZA)
Application Number:
PCT/ZA2015/000056
Publication Date:
March 17, 2016
Filing Date:
August 26, 2015
Export Citation:
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Assignee:
GROENVELD STEVEN CRAIG (ZA)
International Classes:
C12C11/11; A23L3/28; C12C7/28
Domestic Patent References:
WO2007035114A12007-03-29
Foreign References:
US4534282A1985-08-13
US6649204B12003-11-18
GB1293981A1972-10-25
GB254724A1927-09-29
Attorney, Agent or Firm:
SIBANDA & ZANTWIJK (Houghton 2041,Johannesburg, Gauteng, ZA)
Download PDF:
Claims:
CLAIMS

1. A method of making beer including the steps of.

K exposing wort or beer to light within the wavelength range 200 to 700 nanometers to y eld photGlyzed wort beer; ii, fermenting the photolyzed wort/beer to yield fermented photolyzed beer; tii. exposing the fermented photoiyzed beer to ultraviolet .light within the wavelength range 122 to 299 nanometers to yield sterilized beer; and iv. packaging the sterilized beer.

2. A method of making beer including the steps of: i. exposing wort to light within the wavelength range 200 to 700 nanometers to yield photolyzed wort; si. fermenting the photolyzed wort to yield beer; lit., exposing the beer to Sight within the wavelength range 200 -to 700 nanometers to yield photolyzed beer; iv. fermenting the photolyzed beer to yield fermented photolyzed beer; v. exposing the fermented photolyzed beer to ultraviolet light within the wavelength range 122 to 29© nanometers to ield sterilized beer; and vi. packaging the sterilized beer.

3. A method of making beer according to claim 2, wherein prior to the step of fermenting the photolyzed beer, yeast and one or more of carbohydrates and sugar are added to the photolyzed beer.

4. A method of making beer according to either ciaim 1 or claim 3: wherein the fermented photolyzed beer is exposed to ultraviolet fight within the wavelength range 230 to 275 nanometers.

5. A method of making beer according to claim 4, wherein the fermented phoioiyzed wort/beer is exposed to ultraviolet light within the wavelength range 245 to 265 nanometers,

6. A method of making beer according to ciaim 5, wherein the photolyzed wort/beer is exposed to light within the wavelength range 300 to 700 nanometers.

7. A method of making beer according to claim "5, wherein the photolyzed wort/beer is exposed to light within the wavelength range 340 to 550 nanometers.

8. A method of making beer according to claim 6, wherein the fermented photolyzed beer has a riboflavin concentratio less tha 0,2 parts per million.

9. A method of making bee according to claim 6, wherein the fermented photolyzed beer has a riboflavin concentration less than 0.1 parts per million.

10. A method of making beer according to claim 6, wherein the fermented photolyzed beer has a riboflavin concentration less than 0,05 parts per million.

11. A method of making beer according to ciaim 10, wherein the fermented photoiyzed beer has an isohumuione concentration of less than 0.01 parts per million,

12. A method of making beer according to claim 11 , wherein subsequent to fermenting the photolyzed beer, the method includes a further step of filtering the fermented photolyzed beer and/or the sterilized beer.

13. A beer made according to any one of the methods in claims 1 to 2.

Description:
METHOD -OF MAKING BEER BACKGROUND

Th present invention relates. to a method of making beer. More particularly, the invention relates to a method of making beer that uses exposure to ultraviolet light to sterilize the beer prior to packaging.

Historically, beer is brewed, fermented, filtered, packaged (e.g. bottled or canned) and pasteurised using heat to kill microbes and yeast. Since light reacts with hop bitter acids, riboflavin and sulphur compounds in beer, causing the beer to become light-struck 8 produce a "skunky" flavour, beer is typically shielded from light (e.g. by packaging ¾ in coloured glass),

Despite this, various prio art documents describe exposing beer to light. For instance;

GB1 ,293,981 "Method of accelerating the aging of alcoholic beverages" to RDT International Inc. describes irradiating both the wort and the fermented beer with tight within the wavelength range 390 to 480 nanometers to "age" the beer.

US6 ! 5i4.542 "Treatments for improved beer flavou stability" describes a method of making beer, including e: steps of: (i) exposing unhopped (sweet) / hopped wort to actinic radiation within the wavelength range 300 to 700 nanometers (preferably, between MO and 550 nanometers) to decompose the riboflavin to a concentration less than 0.2 pads per million; (fi) fermenting the wort to make beer; (ill) exposing the beer to actinic radiation within the wavelength range 300 to 700 nanometers (preferably, between 340 and 550 nanometers); (iv) adding yeast and syrup to the beer; and (v) refermenting / krausening th beer to remove the "skunky" flavour-Imparting sulphur compounds, otherwise known as 3- IvIBT. The aim of this process is to rende the resultant finished beer less sensitive to exposure to Sight post packaging.

Similarly, US 5,811 ,1.44 "Beer having increased light stability and process of making' 3 , US5, 532,857 "Product and process of making a beer having increased light stability", US6,S49,204 "Hopped malt beverage having enhanced light stability" and US7, 15,290 'Hopped malt beverage having enhanced light stability" to Lafoaif Brewing Company Ltd describe exposing unhopped (sweet) wort to actinic radiation within the wavelength rang 300 to 700 nanometers (preferably, between 340 and 5S0 nanometers) to decompose the riboflavin to a concentration less than 0.2 parts per million, and subsequently: (i) adding hops containing isoacids {i.e. isohumulones) to the wort / beer and fermenting the beer to remove the sulphur compounds.

Although the prior art describes exposing wort / beer to actinic radiation to decompose riboflavin or age the beer, no prior art method uses actinic radiation to: (i) reduce riboflavin in the wort / beer; and (is) sterilize the beer prior to packaging. The actinic light wavelength used in prior art applications is always between 300 and 700 nanometers. The prior art methods sterilize the beer by pasteurisation, which heating negatively impacts the flavour stability of the beer.

If is an object of the present invention to provide a method for making beer that substitutes the step of pasteurising beer using heat with a step of sterilizing ' bee by exposing it to ultraviolet radiation below 3G0 nanometers, preferably within the wavelength range 245 to 2@5 nanometers.

SUMM ARY OF THE INVENTION

According to a preferred embodiment of a first aspect of the present invention there is provided a method of making beer that includes the steps of: X exposing wort or beer to. light within the wavelength.: range 200 to 700 nanometers

•to yield photolyzed wort/beer: ii. ' fermenting the photolyzed wort/beer to yield fermented photolyzed beer; iii. exposing the fermented photolyzed beer ' to ultraviolet light within the wavelengt range 122 to 299 nanometers to yield sterilized beer and iv. packaging the sterilized beer. According to an alternative embodiment of the first aspect of the present invention there is provided a method of making beer that ncludes the steps of: i. exposing wort to light within the wavelength range 200 to 700 nanometers to ield photoiyzed wort; si. fermenting the phoiolyzed wort to yield beer; lii exposing the beer to light within the wavelength range 200 to 700 nanometers to yield p otdfyzed been iv. fermenting the photoiyzed beer to yield fermented photoiyzed beer; v. exposing the fermented photoiyzed eer to ultraviolet light withi the wavelength range 122 to 299 nanometers to yield sterilized beer; and vi. packaging the sterilized beer.

Typically, prior to the ste of fermenting the photoiyzed beer, -yeast and one or more o carbohydrates and sugar are added to the photoiyzed beer.

Generally, the fermented phoiolyzed beer is- exposed to ultraviolet light within the wavelength range 230 to 275 nanometers.

Preferably, the fermented phertoiyzed wort beer is exposed to ultraviolet light within the wavelength range 245 to 266 nanometers. Typically, the photoiyzed wort/bee is exposed to light within the wavelength range 300 to 700 nanometers, More typically, the photoiyzed wort/beer is exposed to light within the wavelength range 340 ' to 550 nanometers.

Preferably, the fermented photoiyzed beer has a riboflavin concentration less than 0.2 parts per million (ppm), more preferably,, less tha 0.1 ppm, and even more preferably, less than 0.05 ppm.

Generally, the yeast and one or more of carbohydrates and sugar added to the photoiyzed beer has an isohumulone concentration of less than O Ol pprn. Preferably, subsequent to fermenting the pbotoiyzed beer, the method includes a further step of filtering the fermented pbotoiyzed beer and/or the sterilized beer.

According to a second aspect of the invention, there is provided a beer made according to any one of the methods according to the first aspect of the invention.

BRIEF DESCRIPTION OF THE ' DRAWI GS '

A preferred embodiment of the invention will now be described in more detail, by wa of example only, with reference to the accompanying drawings in which;

Figure: 1 is a schematic diagram of a method of making beer according to the preferred embodiment of the present invention;

Figure 2 is a schematic diagram of a method of making beer according to an alternative embodiment of the present invention;

Figure: 3 shows a graph of 3-MST levels in beer versus Joules of UV light with a wavelength of 255 nanometers per litre of beer; and

Figure shows a graph of 3-MBT levels ' in beer versus number of passes of beer past a UV light with a wavelength of 380 nanometers.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

With referenc to Figur 1 , according to a preferred embodiment of the invention a method of making beer that allows for the step of pasteurisation by heat to be substituted with the step of sterilization with ultraviolet light (without heating), thereby maintaining the flavour stability of the beer.

The method starts b mixing malt and water in a Mash tun 12 to create wort for the productio of Peer. Optionally, hops may be included in the wort. The wort exits the lauter tun 12 and passed through a first irradiation means 14. The first irradiation means. 14 exposes the wort .to actinic radiation light within the wavelength range 200 to 700 nanometers to yield phoiol ed wort. Preferably, the first irradiation means 14 exposes the wort to..light within the wavelength range 300 to 700 nanometers. More preferably, the first irradiation means 14 exposes the wort to light within the wavelength range 340 to 550 nanometers. This radiation causes riboflavin in the wort to decompose, reducing one precursor of sulphur compounds known as 3~ BT : which impart a "skunky" flavour to the beer. Preferably, such radiation causes the concentration of riboflavin in the photolyzed wort, to reduce o below a concentration of 0.2 parts per million (ppm), more preferably below 0.1 ppm, and even more preferably, below 0.05 ppm. Tests have shown that this typically requires a dosage of actinic radiation of between 25 and 10,000 Joules per litre, preferably between 200 and 5,000 J/i.

The photolyzed wort exiting the first irradiation means 4 is "light-struck" (depending on the isohumulone level of the wort), i.e. includes elevated levels of 3-MBT.

After exiting the first irradiation means 14, the photolyzed wort enters a wort kettle 16, where hops 18 is added and the photolyzed wort (with hops) heated to boiling temperature.

Next, the photolyzed wort enters a whirlpool 2:0 to separate th hops solids from the photolyzed wort. The photolyzed wort is then cooled in a chiller 22, yeast 24 is pitched in. to the cooied photolyzed wort and the photolyzed wort is piped in to a first fermentation .vessel 26 for fermentation.

During fermentation, the levels of 3-M.BT in the photolyzed wort. is reduced. It is thought that this is absorbed / utilised by the yeast, thereby removing the "skunky" flavour of the photolyzed wort.

The photolyzed wort exits the first fermentation vessel 26 as beer.

The beer is then conveyed to a second irradiation means 28, which exposes the beer to actinic radiation / light - within the wavelength range 200 to 700 nanometers to yield photolyzed beer. Preferably, the second irradiation means 28 exposes the beer to light within the wavelength range 300 to 700 nanometers. More preferably, the second Irradiation means 28 exposes the beer to light within the range 340 to 550 nanometers. This radiation causes riboflavin in the beer to catalyse the production of 3-lv BT, and impart a "skunky" flavour to the beer. The results of tests .showing the production of 3-MBT consequent to exposure of beer to UVC light with a wavelengt of 255 nanometers and UVA light with a wavelength of 360 nanometers are displayed in the graphs attached as Figures 3 and 4, respectively. Preferably, such radiation causes the concentration of riboflavin in the photolyzed beer to reduce to below a. concentration of 0.2 ppm, more preferably below 0.1 ppm, .and even more preferably, below 0.05 ppm. Tests have shown that this -typically requires a level of exposure of the beer to actinic radiation of at least 1 Q0J/L The photolyzed beer exiting the second irradiation means 28 is 'light-struck", i.e. includes elevated levels of 3 - BT.

Next, yeast 30 is pitched into, and liquid fermentable extract 32 (i.e. sugar and/or carbohydrates) is added to the photolyzed beer exiting the second irradiation means 28. Preferably, the yeast 30 and liquid fermentable extract 32 added are low in riboflavi and isohumulone concentration (i.e. isohumulone concentration less than 0.01 ppm): More specifically, the degree of irradiaiion of the wort by the first irradiation means 14 and the low riboflavin concentration of the yeast 30 and liquid fermentable extract 32 added to th photolyzed beer ensures that the riboflavin concentration of the photolyzed beer (with yeast and fermentable extract added) is less than 0.2 ppm; more preferably, less than 0.1 ppm and even more preferably, less than 0.05 ppm. Furthermore, the yeast & fermentable extrac added must be free from isohumulone contact, i.e. less than 0.01 ppm.

The photolyzed bee with yeast 30 and liquid fermentable extract 32 added is then piped in to a second fermentation vessel 34 for fermentation. During fermentation, the levels of 3- MET In the photolyzed beer is reduced, thereby removing the "¾kunky :! flavour of the photolyzed beer.

The photolyzed beer exits the second fermentation vessel 34 as fermented photolyzed beer,

Upon exiting the second fermentation vessel 34, the fermented photolyzed beer enters centrifuge 36 to extract yeast and other solids from the fermented photolyzed beer, whereafter the beer is cooled in a chiller 38 before being rested in a maturation vessel 40. After maturation, the fermented photoiysed beer enters a filter 42 to extract remaining solids, and Is stored in a bright beer tank 44.

Typically, beer exiting the bright beer tank is pasteurised by heating the beer to at least 6CFC. However, it Is generally accepted that heating beer causes it to deteriorate.

According to the present invention, instead of pasteurising th beer using heat, the fermented photoiysed beer exiting the bright beer tank 44 enters a third irradiation means 46, which exposes the beer to actinic radiation / ultraviolet light within the wavelength range 122 to 299 nanometers to sterilize the fermented photoiysed beer and yield sterilized beer. Preferably, the third irradiation means 46 exposes the fermented photoiysed beer to .ultraviolet light within the wavelength range 230 to 275 nanometers, more prefereabiy, within the wavelength range 245 to. 265, and even more preferably, to the wavelength 254 nanometers. Exposure of the fermented photoiysed beer to ultraviolet light within this wavelength range causes microbes within the fermented photoiysed beer to be killed. Test have shown that proper sterilization typically requires a level of exposure of the fermented photoiysed beer to actinic radiation of at least 1000J/1. However, since the precursors for the formation of 3- BT have largely been exhausted {i.e. the level of riboflavin .within the fermented photoiysed beer has been reduced to a concentration below 0.2 ppm, preferably below 0.1 ppm, and even more preferably, below 0.05 ppm), this exposure does not produce material amounts of 3-MBT. Accordingly, such exposure does not impart a "skunky" flavour to the sterilized beer.

The sterilized beer exiting the third irradiation means 46 is then packaged 48, i.e. charged in to containers, such as kegs, cans and bottles (whether branded or unbranded).

Optionally, the beer is filtered either prior to passing the third irradiation means 46, or prior- to packaging.

According to an alternativ embodiment of th invention, a method of making beer is provided thai is substantially similar to the preferred embodiment. However, whereas, in th preferred embodiment of the invention, both the wart and the beer are photoiysed, according to the alternative embodiment of the invention, the wort / bee is fermented only once.

Turning to Figure 2, according to the alternative embodiment of the Invention:

β Mail and water is mixed in a Mash fun 112 to create wort fo the production of beer.

Alternatively, fermented wort (i.e. beer is produced),

· The wort / beer enters a first irradiation means 1 4 to expose the wort beer to actinic radiation / light within the wavelength range 200 to 700 nanometers to yield photoiyzed wort/beer. Preferably, the first Irradiation means 1-14 exposes the- wort, .to- light within the wavelength range 300 to 700 nanometers. More preferably, the first irradiation means 114 exposes the wort to light within the wavelength range 340 to. 550 nanometers. • After exiting the first irradiation means 1 14, th photoiyzed wort/beer is piped in to a first fermentation vessel 26 for fermentation.

β The photoiyzed wort/beer exits the first -fermentation vessel 126 as fermented photoiysed beer.

β Upon exiting the first fermentation vessel 126, the fermented photoiyzed beer enters a centrifuge 136 to extract yeast and other solids from the fermented photoiyzed beer, whereafter the beer is cooled in a chiller 138 before being rested in a maturation vessel 140.

• After maturation, the fermented photoiysed bee enters a filter 142 to extract remaining solids, and is stored in a bright beer tank 144,

• The fermented photoiysed beer exiting th bright beer tank 44 enters a second irradiation means 148, which exposes the beer to actinic radiation / ultraviolet light within the wavelength range 122 to 299 nanometers to sterilize th fermented photoiysed beer and yield sterilized beer. Preferably, the second irradiation means 146 exposes the fermented photoiysed beer to .ultraviolet light within the wavelength range 230 to 275 nanometers, more prefereabiy, within the wavelength range 245 to 285, and even more preferably, to the wavelength 2S4 nanometers.

The sterilized beer exiting the second irradiation means 146 is then packaged.

The above methods / processes not only provides for sterilization of the beer In the bright beer tank 44 to be sterilized without heating. But, it also results in a beer with low levels of riboflavin. As such, the sterilized beer according to the present invention is less sensitive to light than normal beer.

The invention also extends to a beer made using the above method / process. The applicant conducted the following tests: TestJi

A 200 litre conventionally hopped ale was brewed and fermented via standard brewing. The resultant bee displayed a hoppy and slightly bitter character (from the hops) with notes of caramel from the speciality malt used. Once fermentation was complete the contents of the fermentation vessel were cooied to S°C to allow for some floccu!ation of yeast. The spent yeast was removed via the bottom fermentation vessel outlet va!ve. The dosage of ultraviolet (UV) light was achieved fay connecting a supply and return hose from the fermentation vessel to a Sure Pure SP4 UV unit delivering 100 Joules per litre per product pass. The hoses and unit were cleaned and sterilized prior to the trial to prevent any microbial contamination. The beer was circulated at 20G0!/hr. through this unit for 2. hours with no measure of the total UV exposure (this is calculated as 120 OOOJ/l exposure). This is a very large dose of UV light and is expected to have yielded beer which could not become any more lighistruck. The product, was organoleptically assessed as lighistruck, burnt, scorched and beyond repair.

This beer was then primed wit fermentable extract and repitched with Ale yeast. Fermentation continued for three days until complete attenuation was achieved. The beer was then sampled for organoleptic evaluation and stored in PET bottles in refrigerator with control samples which were, not UV treated nor re-fermented.

Thai product was assessed organoleptically and no lighistruck character discerned.

This product was stored for 8 months and then tasted again. No-Hghtsteck off flavour was discerned and the beer was palatable whereas the trial product was lighistruck (from Sight exposure in PET) as well as microbial!y spoiled and unpalatable. TestJL,

A 500 litre (bigger batch size required for sampling purposes) conventionally hopped Lager was brewed and fermented via standard brewing practise.

The target *Plato. for the malt portion of the brew was 9.7 Ψ and a volum of 4hL This bre was hopped to yield an isohumulone level of ca. 25 ppm. The yeast pitched was Lager yeas and ferment temperature set at 14 * 0.

Fermentation continued for 72 hours until primary attenuation was -complete. Thereafter the temperature setpoini was reduced to 2 ~ C to facilitate yeast removal. Post yeast removal the SPA unit was connected between two fermentation vessels and a full clean and sterilization carried out to prevent microbial contamination. Beer was transferred between the two fermentation vessels and exposed to l OQJ/i intervals of UV light via the SP4. it is suggested that the effect of UV light exposur is cumulative so that one pass equals 100J/1 and 10 passes equals 1000J/S. Samples for 3-MBT, riboflavin and isohumulone were taken at predetermined, intervals equating to increased levels of UV exposure.

After the target UV exposure levels were reached, the fermentation vessel contents were topped up with fermentable extract (added ambientiy via UV Photosterifeation at 100J I) and repitched with Weiss beer yeast.

Re-fermentation commenced and took 144 hours until complete attenuation was achieved. Thereafte the contents of the fermentation vessel were cooled to 2°C to facilitate yeast removal Post yeast removal, for a second time, the SP4 unit was connected between two fermentation vessels and a full cleaning and sterilization carried out to prevent microbial contamination.

Again beer was transferred between the two fermentation vessels so as to increment the exposure to UV light and again samples were taken for riboflavin and isohumulone analyses.

Two trained tasters from a brewing company were given sample of product post UV treatment 1 a d post UV treatment 2 to organolepticaily assess for any off flavours. Samples ex U V treatment 1 were assessed as extremely Jightstruok with other comments of burnt and onion sulphur. Samples ex UV treatment 2 were assessed as being similar to a conventional Lager beer with a very slight phenolic off flavour {which was to be expected since Weiss beer yeast was used).