- The beer may be in place that is too cold. Move the beer to a warmer place between 21C and 27C. Try using a Heating Tray or Brewbelt to guarantee a constant temperature.
- An old yeast may have been used - adding a fresh yeast should restart the fermentation. Never use a yeast that has gone past the “best before” date.
If you are making beer from grains, make sure that good quality malted barley is used. A slow fermentation can be caused by poor quality malt. If this
is so, then add some yeast nutrient into the beer.