The Grainfather fermentation vats allow me to control the fermentation temperature according to a preset profile. I find that the same profile works well across all of my brews.
- I tend to pitch at around 18-19C. I then set the first 24 hours for 21C. I pitch dry yeast directly onto the wort. It will normally take 24 hours to kick off. If I use a starter, the fermentation will often start pretty much immediately.
- After the initial 24 hours at 21C, the temperature drops to 20C for 4 days. In fact, I don’t tend to cool the fermentation tank – I just leave it do it’s thing! Often the tank will reach around 22C. Why does this happen if the tank is set to 20C? This is due to the yeast generating heat during fermentation.
- If at the end of the 20C period, the fermentation is still very active, I will extend the 20C period for an extra day or two. I only increase the temperature to 23C once the fermentation is starting to slow.
- If the recipe requires dry hopping, this usually happens on day 4 or 5 as the fermentation process is starting to slow. Adding dry hops often seems to revitalise the fermentation process.
- During the 23C phase, the fermentation process is pretty slow. Fermentation usually finishes well before day 10.