PROBLEMS WITH Fermentation: In our fourth article for home distilling beginners, we answer more questions regarding the fermentation process.
This fourth article should now cover some of the issues you might have with your fermentation process and equipment.
Problems With Fermentation: What do I do if the airlock does not bubble?
Within 24 hours carbon dioxide should start bubbling through the airlock if the wash is working correctly and the fermenter is sealed properly. If the gas does not start to bubble through the airlock, then loosen the top and have a look inside.
The wash should be bubbling and will probably have a foam or froth on top. If the wash is not bubbling and there is no froth around the top of the wash then check the temperature is in the recommended range. A vigorous stir at this stage with a sterilised paddle (not wooden) will speed up fermentation.
Stir gently to begin with to avoid a froth build up and then make sure your air temperature is within the recommended range for your particular yeast.
Assuming the air temperature is correct and if it still does not bubble after this, then use your hydrometer by taking a specific gravity reading, write this down and then wait 24 hours and take another reading.
If the reading has dropped that means sugar is being fermented and you simply have a leak in your lid where gas is escaping. This is very unlikely to affect your wash so just leave a lid on and you can determine when it is finished when you get a hydrometer reading of 990.
Float the hydrometer into a sample of the wash in a test tube, and take the reading where the surface level of the liquid cuts across the scale on the hydrometer.
How do I check that I have a good airtight seal on my fermenter?
If the airlock is not bubbling after 24 hours it is most likely that the fermenter is not sealed properly. Check you have pressed the lid on correctly.
Next, check you have a good seal by lightly pressing the sides of the fermenter to force some air out through the airlock.
When you release the pressure on the barrel the air should try to get back in through the airlock. If sealed properly the water level should remain uneven in the airlock (more water on one side than the other).
How long should fermentation take?
Fermentation can take as little as 4 days. In cooler weather it could take up to 7 days or more but this usually doesn’t mean problems with fermentation.
Note that for the first 24-48 hours, heat is generated from the fermentation process.
DO NOT ADD ANY HEAT DURING THIS TIME.
After this period a Heater Pad or Heat Belt may be used in cooler weather to maintain the temperature.
Fermentation is complete when the yeast has used up all the sugar. There will be no bubbles rising through the wash and the wash hydrometer reading will have been static for two days.
Float the hydrometer into the wash or a sample in a test tube, and take the reading where the surface level of the liquid cuts across the scale on the hydrometer; the reading should be about 990.
Until next time… Happy Distilling!