I'm having my first go at home brewing by making elderberry wine. So far so good. I've just put the wine in a demijohn for the anaerobic stage of the process. Based on what I read I've filled the demijohn so there is no gap between the liquid and the bung. I'm using a bubbler airlock. the wine has been in there for a few hours and wine has been pushed into the base stem of the bubbler and the water has been pushed into one side of the bubbler even though I initially set it up with both sides half full.

From all the videos I've watched this doesn't seem right. Though I thought I'd ask and see if the best thing to do is just leave the bubbler as it is with the wine in the bottom of the stalk. Or take the bung and bubbler out, sanitize them, drain a tiny bit of wine from the neck to create a small gap between the bung and the liquid and then replace the bubbler. Which is the correct approach?

thanks for reading?

1 Answer 1


My instant advice is to take the bung out of the demi-john, pour out enough liquid to leave at least 2 inches (or more) above the liquid. Flush/clean the bubble trap and refill as before, then fit the bubble trap back on . Leave wine to ferment as normal.

There REALLY SHOULD be an air gap above a fermenting liquid in a demi-john as the fermentation can produce vigorous bubbling and a large volume of surface foam. When that happens the only place for the foam/juice to go in a filled demi-john is up into the bubble trap.

A fermenting brew can handle a reasonable amount of air without problem. So the fact there is some air above the fermenting juice is OK. I usually do not fill a demi-john above its "shoulder" (where the glass bends from vertical towards the neck).


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