Ensuring that neither the appearance, nor the taste of beer changes before its best-before date is one of the greatest challenges that brewers face. Experts examine how beer ages on the bases of three factors: microbiological, physicochemical, and flavour stability. The physical and chemical stability is defined by the speed and intensity of hazing.
Forced ageing tests are therefore common as a standard quality control measure for every brewery to predict the shelf-life of their beer.
What is “accelerated ageing” and how can a cooled incubator be used effectively for these tests?
What is accelerated ageing?
Accelerated ageing is a well-established method that is used to simulate normal storage that may last for several months, conducted over the course of a few days. This is achieved by increasing the storage temperature used to predict the shelf life of beer.
The main factors that influence the stability of beer are temperature and oxygen ingress during production and storage, as well as exposure to UV light, with elevated temperatures accelerating the oxidation processes in beer most dramatically.
The hazing that takes place during the accelerated ageing process provides a kind of blueprint for the irreversible, permanent haze of old beer. The turbidity is measured at the end of each of the cold phases (24 hours at 0°C).
If a certain degree of difference in turbidity relative to the initial turbidity is reached, the brewer can calculate the shelf life of the beer using a formula based on the number of warm days (warm phase + cold phase) involved. As a rule of thumb, one warm day corresponds to one month of shelf life.
Benefits of using a cooled incubator for your beer-ageing tests:
Memmert’s cooled incubator ICP is widely used to control the temperature of the beer samples, instead of a water bath. Although heat transfer is known to be slower in air than in water, studies have shown that it is the temperature differences, rather than duration of the heat transfer, that is critical in this process.
- A cooled incubator is safer, because in a water bath there is a risk of bottles bursting during the heating phase.
- Bottles can be removed from the cooled incubator and put directly into the turbidity meter dry after the cold phase, without wiping them first.
- Display and documentation of the temperature profiles and simple programming of individual forcing tests is possible.
- An alarm can be set for temperature deviations so that it shuts down automatically at 70°C.
- Last, but not least, you can programme the fan to run at full speed automatically during the heating and cooling phases to minimise the formation of condensation.
Breweries have tested and approved the precisely controlled Memmert cooled incubators as an attractive alternative to water baths to temper bottles for shelf life testing.
This is just one example of the many applications that can be achieved through use of the Memmert range of quality German equipment. Come talk to us about your application at analytica Lab Africa.
- Barbara-lee Nel, Product Manager - Instruments