Patent GB-715948-A (GB)
Title: Improvements in the manufacture of beer
IPC: C12C7/04
Filed: 1951-03-30
Abstract: In the production of beer, one or more of the materials, hops, mash, wort, diluted wort and sediment are treated at an elevated temperature with ultrasonic vibrations, carried out in the presence of water or aqueous liquid in the case of hops or sediments, and the product or products used in the making of beer. The hops may be extracted for 60 to 120 minutes in the presence or water or aqueous liquid preferably soft water or wort or a mixture thereof in the ratio of 180 to 200 parts to 1 part of hops at a temperature preferably kept constant, e.g. 50 to 60 DEG C, and the extracts thus obtained may be employed for hopping the wort and may if required be concentrated by known means whereby a reduction of the amount of hops used by 40 per cent is obtained. In addition to the hop extract, natural hops may also be used for hopping the wort.  The bittering substances occluded in the sediment may be separated and recovered by ultrasonic vibration of the sediment in the presence of water, e.g. brewing water or an aqueous solution, and used in the brewing process (wort boiling) or as part liquid quantities in the carrying out of ultrasonic hop extraction.  Ultrasonic treatment of mash and wort can be carried out advantageously at a relatively high temperature, e.g. between 50 DEG C and the boiling temperature, considerably improves the properties as regards taste, smell and the material composition. The extraction of the bittering substances from, for example, hops is carried out by mixing the weighed amount of hops with the extraction liquid, e.g. decarbonated brewing liquor or the diluted wort resulting from the washing out (sparging) of the spent hops separated from the first wort or even the first wort itself heated for example to 50 DEG  or 60 DEG  C and the mixture kept in motion for a few minutes and then the ultrasonic treatment is started in an apparatus of known type.  The amount of liquid to be added to the weighed hops is regulated according to the concentration ration of hops to liquid which is to be set at any time.  When the extraction is completed the bittering substance extract can be separated from the spent hops, for example by suction, and used again separately.  In an example in the manufacture of Pilsner type beer with 173 hectolitres of final wort the normal hop consumption of 50 kgs. was reduced by 40 per cent to 34.8 kg. From the first wort about 22.5 hectolitres were fed into the hop strainer and adjusted to 50-60 DEG C mixed with 17.4 kgs. hops and subjected to ultrasonic extraction for one hour when the spent hop and bittering substance extraction solution were separated, the spent hops being immediately passed into the boiling wort to precipitate proteins and the bittering substance extract added to the boiling wort so that it boils with the latter for about 1 1/2 hours. The remaining 17.4 kg. hops are extracted in 19 hectolitres of diluted wort at 50-60 DEG C with ultrasonic vibration and the extract and spent hops are separated, the latter immediately returned to the boiling wort whereas the former is so added to the wort that, for example, 12 hectolitres boil with it for one hour and the remaining seven hectolitres for only another 15 minutes.  A final wort was obtained having 30.26 grams of bittering substance per hectolitre compared with only 14.7 grams of the normal method.  In another embodiment the spent hops and the extract are added together to the wort, e.g. at the commencement of the boiling.  According to another embodiment about two-thirds of the extract is added with the spent hops to the boiling wort, while the remaining third is stored in a heatable vessel at e.g. 70 DEG C and only added to the boiling wort a short time, e.g. quarter of an hour, before the tapping of the brew whereby the valuable hop oils are preserved.  According to another embodiment the extraction is effected on a through-flow principle in a separate strainer connected between the clarifier vat and the wort pan.  In this case the substance flowing through, which is enriched in bittering substance, may be collected in a further vessel and introduced in suitable quantities and at intervals into the wort, or the extract of hop bittering substances may pass directly into the wort pan without separation when the spent hops are supplied from the strainer to the wort pan on completion of the through-flow process.