PROOF TUBE of glass with 2 balls large 18 mm

made of glass with 2 balls, mouth blown, for rubber stoppers with 18 mm hole, for fermentation vessels from approx. 30 -120 l.

Prevents air from entering during fermentation, but allows the fermentation gas (CO2) to escape without problems.fill fermentation tube to half the height of the ball and close the fermentation vessel with it using rubber stoppers. If you use the blocking liquid listed below instead of water, you can also use the fermenting cap as a beverage protector. Sulfurous solution: mix 2g of potassium pyrosulfite (or 2 crushed Oenwe tablets), 1g of citric acid and 100ml of water and pour into the fermentation tubes. If the must is now tapped, the aspirated air must pass through the barrier liquid, and is thus rendered sterile.