Among the brewers there is a saying that "the brewer prepares the wort and the beer makes the yeast" Which means clearly that the most important stage of beer production is fermentation. There is a lot of truth in this, because the taste properties of many styles of beer are created thanks to the appropriate strains of yeast and properly conducted fermentation. Such beers undoubtedly include Belgian styles, German wheat beers, English ales, and probably all kinds of lagers. Even a seemingly uncomplicated beer like the American IPA, whose taste is primarily responsible for a good dose of aromatic citrus hops, can be spoiled or polished like a diamond by fermentation conditions.
The key to perfect fermentation is, in addition to yeast, precise temperature control.
It doesn't just mean setting one level of fermentation temperature throughout the entire fermentation period. Which usually comes down to a cold cellar for lagers and an apartment for top fermented beers. Ideally conducted fermentation is maintaining the temperatures at certain levels depending on the fermentation stage. Usually, the idea is to start fermentation in the low temperature range of a given yeast strain and gradually raise the temperature over time. Thanks to this, we can avoid undesirable aromas in the beer, which are formed at the beginning of fermentation, when the yeast rapidly starts to raise the temperature of the wort. It is very important if we want to emphasize the flavors of malt or hops. For a clean lager profile, the diacetyl gap is important, i.e. raising the fermentation temperature by 5-10 degrees in its final stage. Thanks to this, we reduce the presence of diacetyl in beer, which causes a buttery aftertaste in the beer. In strong top-fermented beers, the low initial temperature allows the alcohol to be hidden in the finished beer and to reduce the presence of acetaldehyde with the aroma of green apples or even emulsion paint. Acetaldehyde is also one of the main causes of alcohol intoxication, commonly known as a hangover. In Belgian beers or fermented with kveik yeast, it is important to obtain fermentation temperatures in the range of 25-35 degrees to obtain the appropriate flavor effects. These are just a few examples of how important it is to control the temperature during beer fermentation. 

 

 

Until recently, it was one of the most difficult challenges for home brewers. Various types of structures based on refrigerators, thermal insulators and heaters allowed for more or less successful temperature control. However, there is a tool that will allow us to raise our home brewery to the standards of an almost professional brewery when it comes to fermentation. We are talking about the system offered by Grainfather, which includes GF30 steel fermentation tanks and Glicol Chiller glycol cooling agergate. Thanks to them, we can fully control the fermentation temperature at each stage in the range from 4 to 35 degrees C. At the same time, connect four fermenters to the aggregate, each of which will work at a different temperature.

 

 

Let's take a closer look at the entire system.

Stainless steel conical fermenter - Conical Fermenter Pro GF 30
Fermenter height - 910mm, with a fermentation tube 1090mm
fermenter diameter with handles - 360mm
total weight - 17 kg
maximum volume - 30l (use marking up to 25l)
Double valve tap with 110 mm (4.3 ”) inlet
a 5 cm (2 ") hole in the bottom of the cone
Heater 30W
Maximum fermentation pressure 2 psi 8 cm sleeve on the lid (for anti-pressure transfer)
Temperature controller with the possibility of connecting via WiFi to the Grainfather app

The fermentor has double walls, inside which there is a cooling jacket and a heating system. Thanks to this solution, there are no additional elements inside the fermenter, such as a cooler or heater. The fermenter is therefore easy to keep clean and much less emergency. The temperature is raised gradually, without the so-called hot places that could adversely affect yeast and fermentation.

 

 

 

 

 

 

The bottom of the fermenter is cone-shaped with a 60 ° drop angle. This is the optimal slope for free fall and collection of the yeast slurry at the bottom. Thanks to this design and a special valve at the bottom, it is possible to easily collect the yeast cream at any time during fermentation. This is especially useful when you want to reuse the same yeast or hop the beer cold.

 

 

 

With a separate tap above the slurry drain valve, we collect beer samples and pour gravity directly into the bottles. Beer flows into the tap through a tube attached vertically in the bottom of the cone above the sediments. Thanks to this, we can take clean samples without yeast or hops.

 

 

Let's move on to the most important function, i.e. temperature control during fermentation. Its level is set manually on the controller or on the connected Grainfather application. Of course, the condition is to connect the fermenter with the glycol cooler. By manually setting the temperature, we enter the appropriate value on the controller and the hysteresis range - i.e. the margin of deviation from the programmed temperature. This is an acceptable range when neither cooling nor heating systems are started. The recommended hysteresis range is 0.5 degrees. At lower values, e.g. 0.1-0.2 degrees, the temperature maintenance systems will work practically all the time. Higher values, i.e.> 1 ° C, may influence the fermentation effects. By writing one temperature value and turning on the fermenter, the system will maintain the programmed level throughout its operation. Subsequent changes must be made manually.
Another option is to program the fermentation profile, which can also be done via the controller. Then, we program the temperature values ​​for each fermentation day and after starting the system, the saved profile is realized. Importantly, after the end of the programmed fermentation, the fermenter maintains the temperature of the last fermentation day by default until it is manually turned off.

 

An extraordinary advantage of the entire system is the ability to control it remotely through an application on a phone connected via WiFi. For this purpose, we install the Grainfather application to control all devices of this brand and to create your own recipes. Then we add our fermenter to it. At this point, we can use the ready-made fermentation profiles saved in the application. The ready profile is the optimal course of fermentation for a given style of beer, eg Pils. We can also save our own fermentation profile by setting the desired temperatures in the course of fermentation. By starting the system through the application, we can view the fermentation process via a graph. Importantly, we can stop it or change the saved values ​​at any time. Thanks to the connection via WiFi, we have control over the equipment from anywhere in the world with access to the Internet. It is worth adding that it is possible to add to the application devices measuring the level of beer fermentation on an ongoing basis (eg Tilt, Plaato). Thanks to this, the values ​​of the current attenuation of the wort will be added to the temperature chart during fermentation. It is a very useful solution that gives insight into the current state of fermentation and adjusting appropriate temperature scenarios to it.

 

 

 

 

It is also worth mentioning the possibility of fermentation under the pressure of approx. 2 PSI, thanks to which we can pour beer saturated with carbon dioxide directly into the bottles. For this you will need a Pressure Transfer Grainfather Conical Fermenter kit and an external CO2 cylinder.

 

 

 

Glycol Chiller

Dimensions: 390 x 450 x 656 mm
Weight: 28.3 kg
Power consumption: 300W
Power supply: 220 - 240 V, 50 Hz
Capacity - 6L glycol tank

The principle of operation of the refrigerator is simple. Fill the glycol tank inside the refrigerator with a mixture of glycol and water (2l of glycol / 4l of water), according to the instructions, bleed the internal system of the refrigerator and connect the fermentors. The maximum number of connections is four fermentation tanks. The refrigerator cools down the glycol (to -4.5 ° C by default) which is pumped into the jackets of the fermentors until the temperature programmed on each of the fermenters is reached. When you buy a cooler, you get complete hoses for connecting one fermenter. If you want to connect other tanks, you should buy a set of Cooling Connection GF Conical Fermentor hoses.

 

 

 

An interesting alternative to a glycol cooler is the possibility of cooling the fermentors with cold water placed in an external tank. For this purpose, we need a set of hoses with a special Cooling Pump Kit GF Conical Fermenter. We immerse the pump in cold water, connect the hoses to the fermentor, and the controller activates it to achieve the programmed temperature. Of course, this is a simple solution with many drawbacks, such as the need to keep the water temperature low and much less efficient cooling than in the case of a glycol cooler.

 

 

 

Summarizing the presented system is a revolutionary solution for home brewing. The effects that can be achieved so far have been very difficult to achieve by brewing amateurs. Thanks to it, you can get closer to the level of the world's best breweries and implement all assumptions of ideal fermentation conditions.