Brewing with high-gravity worts.
As both wort and beer are mainly water much of the energy expended in brewing is essentially wasted. The paper describes some attempts to economize by reducing the water concentration throughout the process. High gravity worts could not be produced in a single stage but the problem was overcome by using normal wort as mash water and spargings for subsequent brews to give worts up to twice the normal strength. Hopping and boiling were carried out as normal although post fermentation bittering is recommended because of greatly improved hop utilization. Fermentation was carried out successfully although requiring a longer time for the stronger wort. Yeast production appeared to be independent of wort strength so that beer produced from the stronger worts had substantially elevated amino acid contents. This may allow the use of a higher adjunct ratio in high gravity brewing. No variation from the normal pattern of volatile compounds was observed. Deaerated water or hopped water with a pH of 4.5 was used to dilute the finished beer to an appropriate alcohol content.
Keywords: high gravity brewing wort