Lesson 7 - Processing Aids and Additions SAQ
This lesson allows you to test yourself on the material covered in the Processing Aids and Additions lesson, and determine the level to which you have met the learning outcomes.
Suggested Response - Q5
**You want to start brewing your best-selling lager at higher gravity to meet increasing customer demand whilst improving production efficiency. You have been asked to compile a business case to invest in cellar operations to meet demand. What are the benefits of brewing at high gravity, and what plant should you consider installing to achieve final pack specifications from high gravity beer?
Response:
Brewing at high gravity requires product adjustment post-filtration, to achieve final pack specifications. In particular, the matured and filtered beer needs to be diluted to target alcohol, and carbonation levels need to be adjusted. Beer is brewed at high gravity by many brewers to improve the efficiency and volume output capability of a brewery. Producing a more concentrated form of a brand produces a greater volume from the same brewery footprint.
To achieve both accurate and repeatable dilution and carbonation, the brewer will need a carbo blender to obtain in-pack % ABV and gas level specifications. Carbo blenders are typically mounted on a skid and are equipped with several specifically designed vortex injectors that inject the gas as fine bubbles, into the liquid stream.
These nozzles ensure that the carbon dioxide dissolves homogeneously in a very short time. At the outlet of the system, the CO2 content is measured in real-time with a sensor. Based on this accurate in-line measurement, the gas flow is adjusted instantly and is fully automated. Deaerated water for product dilution is also added using accurate flow meters, automatically responding to the in-line % ABV measurement sensory, which controls the deaerated water addition rate. This ramps up or down depending on the % ABV of the beer outlet pipe. The carbo blender system beer pipe is designed in a snaked arrangement to promote the mixing of deaerated water and dissolved gas to achieve a homogenous liquid.
The brewery must also have an ample deaerated water supply and the brewer should review the dilution water capacity to ensure it can meet the demands of the carbo blender. Water must be filtered, sterilised and deaerated prior to use in order to meet the water specification used in the plant. The water must also be free of oxygen (< 10 µg/L) and free of any volatile compounds that could impact the flavour of the beers. Equally the brewery should have sufficient CO2 storage and supply to carbonate the lager from typically 1.2-1.7 v/v to 2.2-2.8 v/v.