Temperature control in low and no-alcohol brewing extends from mashing and wort cooling to alcohol removal and pasteurisation, with heat exchangers providing opportunities to recover and reuse energy between production stages.
HRS Heat Exchangers global business development director Matt Hale says many of these products use conventional brewing equipment, but recipe design, process control and packaging management become even more important when alcohol is reduced or absent.
Brewers generally either restrict alcohol formation during fermentation or remove it afterwards. Limiting fermentation can involve stopping the process early or selecting maltose-negative yeast strains. Physical removal methods include vacuum distillation, evaporation and reverse osmosis.
Ethanol contributes to taste, mouthfeel and shelf life, making its removal a formulation challenge as well as a processing task. Hale says yeast, hops and sweeteners can compensate for the lack of alcohol, while improved yeast strains have helped brewers address flavour and aroma weaknesses.
During mashing, temperatures above 72°C and shorter mash times can reduce beta-amylase activity and limit subsequent fermentation. After boiling, wort must be cooled rapidly to prevent off flavours caused by dimethyl sulphide. This typically involves reducing temperatures from around 95°C to 12°C. Both plate and tubular heat exchangers can perform this duty.
Where vacuum distillation removes alcohol, close temperature control is needed to avoid undesirable flavours. Hale identifies heat exchanger-based evaporation systems, including the corrugated tube HRS K Series, as suitable for beers with low viscosity and fouling potential. Heat exchangers can cool fermented beer before maturation or bottling, using chilled water or other coolants while maintaining continuous processing.
With less alcohol and fewer of the microbial deterrents present in conventional beer, low and no-alcohol products require particular attention to pasteurisation. High-temperature, short-time treatment supports microbial stability and shelf life while helping preserve taste. Hale identifies the HRS MI Series of multitube corrugated heat exchangers and integrated HRS Thermblock Series systems as options for this production stage.
Heat recovered during wort cooling provides another engineering opportunity. The warmed cooling water can reach around 80°C and be reused to preheat wort before boiling, reducing the energy required.
Brewing waste streams provide further applications. Wastewater and slurry containing yeast and sugars can feed anaerobic digestion systems, where heat exchangers provide digester heating, digestate pasteurisation and evaporation to reduce water content. Evaporation can reduce the water content of spent grains destined for animal feed or bioenergy applications.
Hale says capturing surplus heat from cooling operations and other sources can support increased capacity or additional production processes without major new heating infrastructure.
Depending on the application, he says HRS equipment has recovered as much as 50% of previously wasted heat. That energy can be used for water, space or process heating, waste treatment and other thermal duties.
