In this article, we'll explore the thought processes of how to select the best fermentation recipe on your iGulu F1.
On the touchscreen of the fermentation device, there is a list of fermentation methods, with 4 common fermentation methods available for selection:
- Ale Two-Stage
- Ale Three-Stage
- Lager Two-Stage
- Lager Three-Stage
The current fermentation method is composed of two key variables: temperature and number of days, which serves as the basis for the device's automatic temperature control of the fermentation tanks. In the future, iGulu will also introduce pressure and other key variables.
It is well known that the conversion of wort into beer is the job of yeast, and the brewmaster's job is to create a suitable environment for the yeast. We can influence the fermentation activity of the yeast by controlling the temperature, and yeast as a simple organism, with a significant impact on the yeast.
What temperature is most suitable for fermentation? This depends on the type of yeast strain, the type of beer, and the flavor that the brewery wants to achieve. Generally, Ale yeast ferments best at around 20°C, while Lager yeast ferments best at around 10°C. However, this is not the yeast's most suitable temperature. Ale yeast grows fastest at 32°C, while Lager yeast grows fastest at 27°C. Then why ferment beer at low temperatures? Because at higher temperatures, the yeast ferments too quickly, and the yeast population grows too much, producing unwanted flavor substances in the beer, such as fusel alcohol. In the historical development of brewing, brewmasters have kept fermentation under control in a temperature range that is not too low, in order to ensure the growth rate of yeast, while improving the flavor of beer.
Because yeast is a simple organism, it is sensitive to temperature changes. Within a suitable temperature range, the higher the temperature, the stronger the metabolism and the faster the fermentation speed of yeast, but unwanted fermentation by-products may also increase. If the temperature is too high or too low, it may cause fermentation to stop. Therefore, it is important to select an appropriate temperature to ensure flavor, while allowing sufficient time for the yeast to complete the fermentation process.
Therefore, the main difference in the current common methods is in temperature and fermentation time. Choosing a fermentation method that suits you is crucial, and the key is to first determine the style of beer being brewed and the type of yeast used, whether it is Lager or Ale. Refer to style introductions and yeast usage instructions to understand the appropriate fermentation temperature range. For example, recipes for wheat, pale ale, and IPA can choose Ale-type fermentation methods. Lager, Pilsner, and Bock beer can choose Lager-type fermentation methods. Then select the fermentation time based on the concentration of wort. Wort with higher density can choose a temperature that is relatively high but has a longer fermentation time to avoid incomplete fermentation, which can leave too much sweetness or negative flavors in the beer.
At the same time, you will find that fermentation methods have two stages, or sometimes three stages. Apart from the final refrigeration phase, in reality, there is only one temperature for fermentation, or the fermentation temperature starts out lower and is increased by 2°C in the later stages. This is because the brewmaster wants the temperature rise to promote yeast metabolism to complete fermentation more thoroughly and break down some of the intermediate substances in the early stages of fermentation that produce negative flavors. However, the current commonly available recipes are quite limited, and the distinction between two-stage and three-stage methods is merely exemplary, indicating that the device can control multiple temperature stages.
Developing a fermentation method is like making clothes. Currently, we only have two styles, with only two sizes (M and XXXL) for each style, which can only ensure that most people can wear them, but may not be desirable or fitting. Future iGulu will continuously and endlessly unlock new fermentation methods for customers, but each beer style or yeast strain has its own characteristics, and brewmasters also have their own temperature control habits. Some brewmasters are very precise in controlling temperature and time, and the entire brewing controlled temperature may have more than 5 or 6 different temperature stages. If you are an experienced homebrewer or brewmaster or want to explore more temperature control possibilities, it's best to purchase our Master Mode Card, which unlocks customizable fermentation methods for your beer.
Notes:
[1] Reference: 'Yeast: the practical guide to beer fermentation'
