Hello how many days into fermentation does it take for it to slow down. Meaning when I see a recipe that say to raise the temp as the fermentation start to slown down ?
That’s hard to answer as there are too many factors left out of the question. OG of the recipe, specific yeast strain, and fermentation temps can each swing the answer by days. Plus, yeasties can just be unpredictable.
I’d watch the krausen, and start raising the temp as it starts to look thinner.
How many days it takes to ferment depends on the recipe, the yeast strain, the amount of yeast pitched, the temperature and a bunch of other factors. It can’t be simplified to a set number of days. That’s why the advice is given as it is.
But in general, ales can take anywhere from 2 to 10 days to ferment out, and lagers about 50% longer.
If you only want to monitor the gross changes in activity, you can watch the airlock and when the bubbles start to take longer to form, it is probably about time to raise the temperature (if that is you plan). For truly determining when fermentation is done, you should measure specific gravity. When the gravity reading is the same for 2-3 days in a row, the fermentation is done.
