A wise man once said that the brewer only makes wort, while the yeast makes the beer. So the yeast needs to be happy. That is your job as a brewer, and the key lies in good temperature control.
We will therefore not go into depth on the fermentation process itself, but rather explain why temperature control is so important, and which solutions may be relevant for you.
Happy yeast makes good beer
You could write long articles about yeast and the fermentation process, but for the average homebrewer it can quickly become rather dry reading. So we will not go too deep into that, but rather explain a little about why temperature control is so important, and which solutions may be relevant.
To explain simply how yeast works: yeast is a living organism that eats sugar and converts it into alcohol and CO2.
If these little critters are not happy and cannot eat in peace, they can produce various off-flavours that are unwelcome in the finished beer. The off-flavours can come in the form of butter, popcorn and spice; solvents, bandages and sticking plasters. In addition, some more demanding yeast strains can dig in their heels and refuse to ferment any further if they are not happy.
Other factors that can play a part are whether there is enough yeast and whether it is healthy (fresh). Storage before pitching into the fermenter is also important, and can determine whether fermentation starts or not.
Why invest in temperature control?
Like other organisms, yeast does not like it when it is either too warm or too cold. Even though a good brewing system can pay off, temperature control is one of the smartest things you can invest in to make a real leap in quality. Different yeast strains give different flavours, but the same yeast can also give different flavours at different temperatures.
With full control over the temperature, you can also make changes to your recipes to perfect your beer. There are several methods for keeping track of this, and plenty of good measuring equipment that makes the job easier.
A stable temperature is crucial for fermentation
One of the most important things about the temperature is that it stays stable over time. Many a homebrewer has been caught out by putting the fermenter in a room they think is stable:
- A room that holds 18°C in the evening will not necessarily hold the same temperature when the sun shines the next day.
- The yeast itself produces quite a lot of heat, especially at the start of fermentation during the most vigorous phase.
Even if the room holds around 18°C in the evening, it can quickly rise towards 30°C when the sun shines directly on the fermenter the next morning, and then drop again as soon as the sun disappears round the side of the house. Still, a room with a stable temperature is a better solution than big changes during fermentation. In winter, for example, a cold cellar combined with a simple heat source can be a solution.
Take control of the surroundings
Choosing a fridge with a thermostat is a good start. It is simple, cheap and a good option for controlling the temperature during fermentation. You can often get hold of a cheap, or perhaps even a free, fridge with room for a fermenting bucket.
There are several options for controlling the thermostat, but for simplicity we can recommend the Inkbird WIFI ITC-308. This is a good and inexpensive option that controls both cooling and heating during fermentation. Plug the fridge into the cooling socket on the Inkbird, and ideally a heat source into the other socket for heating. Place the temperature probe inside or against the fermenter, and set the temperature you want. The Inkbird does the rest of the job for you. Simple, smart and cheap.
We also recommend a heat source for full control, such as a heat wrap that sticks around the fermenter, or a heat pad placed under the fermenter. If you want to simplify the process even further, a thermowell may be the solution for you. Place the probe well inside the fermenter without it touching the beer for the most accurate reading.
Ferminator revolutionises temperature control
Brewolution in Denmark has recently developed a good and affordable system, Ferminator, which gives full control of the temperature during fermentation. The concept is in many ways similar to the fridge solution, but the cabinet itself is built from EPS/polystyrene:
- The construction makes the cabinet easy to handle, and it can be taken apart when not in use.
- The package includes a unit that provides both cooling and heating.
- A controller to set the temperature the way you want it.
- A fan for good circulation inside.
- Low price and good insulation.
Extension modules are also available for the cabinet, so it can be built to fit exactly the fermenter you have, and even Cornelius kegs to keep your finished beer cold.
Glycol cooling
With a glycol chiller we are really talking temperature control, plus the option of an effective cold crash after fermentation to clear the beer. More recently, several smart solutions have also appeared that let you use glycol cooling with perfectly ordinary fermenters.
First and foremost you need a proper glycol chiller from, for example, Quantor, Lindr or Grainfather. These can chill a mixture of water and glycol to below zero. It goes without saying that this gives fast and effective cooling. In stainless steel fermenters from, for example, Brewtools or Grainfather, the cooling liquid is pumped through a double wall in the fermenter (jacket cooling), while in other tanks the coolant runs through a cooling coil in the lid or side of the vessel.
Water cooling
A cheaper alternative to glycol is water cooling. In many ways this works the same as glycol cooling, but cold water from the tap or an ice bath is pumped through the cooling system instead. There are several do-it-yourself solutions: a solenoid valve that opens and closes the cold water tap for you, or a submersible pump that can pump an ice bath through the cooling system. Our "Temp Control Pump Kit" with a submersible pump and Inkbird temperature controller is a popular option for this.
Here your imagination is really the only limit, and the possibilities are great for those who are handy.
If you need advice on choosing temperature control and a glycol chiller, whether for homebrewing or a professional setup, just get in touch with us.
