Subculturing is transferring the culture from an existing culture to a new growth medium.
This is called subculturing or "passaging" the culture. Subculturing prolongs the life of a culture, but after time can deteriorate and off flavors or "notes" might be detected. With good practice you can passage batch after batch of eugurt and enjoy quality eugurts for years.
The easiest way to do this is to save and freeze a small portion of eugurt after fermentation - 1 tbsp is all that is needed! Of course, you could just take a spoonful of one of your eugurts to start the next batch, too. Just make sure you haven't eaten out of it first! See below for more detail.
- Simply take a tablespoon of virgin eugurt and use it to culture your next batch. This replaces the culture packet.
For best and most consistent results, the eugurt used for subculturing should be untouched. If it has been eaten from the probiotic culture has been altered.
This isn't to say it won't work, but the quality may be affected and you won't get as many passages out of the eugurt.
With that said, even the most diligently maintained culture/subculture may eventually need a refresh.
If you begin to notice your eugurt tastes different, has off flavors, or isn't as fresh - it might be time to re-culture with a direct-set Eugurt Culture.
The 6 pack Eugurt Non-Dairy Starter is provided for this reason. A single 6 pack will keep in the freezer for 2 years with no loss of activity.