IN OUR FIFTH article for home distilling beginners, we answer even more questions regarding the fermentation process.
Our previous Beginners’ Gems posts containing helpful hints, tips and techniques for home distillers, include the following:
This fifth article should now cover even more of the issues you might have with your fermentation process and equipment.
What do I do if my yeast stops working before all the sugar is used up? How do I restart my fermentation?
Make sure that your mix has not actually finished by checking the Specific Gravity (S.G.) with a hydrometer.
The S.G. should be around 990. If the SG is higher and all sign of fermentation has stopped the best way to guarantee a restart is to start a second yeast, but use only 6kg of sugar.
Allow to the second yeast to ferment for only 48 hours and then split into 2 fermenters and add half the stuck brew to each half of the fresh fermentation.
What can I do if the yeast stops working before all the sugar is used? How do I tell?
In some circumstances the yeast can stop working before all the sugar is used. This will be indicated by a final hydrometer reading higher than 990.
Any reading above 1000 on a standard hydrometer suggests that something has gone wrong.
This is called a stuck ferment. In most cases a good stir to get the yeast back into circulation should get the wash fermenting again.
The most common cause of stuck fermentation is low temperature. In this case simply move the fermenter to a warmer place and stir the yeast back into the liquid.
An inexpensive stick-on thermometer will help monitor the temperature. If you are having problems maintaining a warm enough temperature use a heating pad.
This will be especially important if you want to continue to brew throughout winter.
A less common reason for a stuck ferment is the liquid gets too hot and kills the yeast.
Also if you put more than the recommended dose of sugar it may produce too much alcohol which kills the yeast.
My wash started to ferment but stopped and my hydrometer reading is not down to 990 SG? Why?
It’s probable the temperature rose too high in the first 24 hours of fermentation. It’s important to note that yeast activity can raise the wash temperature by as much as 8°C (46°F) in the first 24 hours of fermentation.
It’s essential to start the wash at the recommended temperature for the specific yeast you are using.
Also, do not use any heat in the first 24 hours. If the wash overheats during this period the yeast may not have the energy to finish fermenting.
If this has occurred, first stir the wash vigorously to stir the yeast back into circulation. You then have two options:
Option One: Distill the wash as it is, but only when you are satisfied it will not ferment any more. You may not get as much alcohol as you would from a normally fermented wash. Watch the temperature on the condenser and stop when you have reached the appropriate maximum temperature for your model.
Option Two: Restart your wash the best way to guarantee a restart is to put on a new yeast is best) but use only 6kg of sugar. Allow to ferment for only 48 hours and then split into 2 fermenters and add half the stuck brew to each half of the fresh fermentation
Until next time… Happy Distilling!