Cut the elderflowers from the stems, rinse with cold water and drain in a sieve. Melt the sugar in warm water. Fill the sugar solution into the balloon, as well as the cold blossoms (do not boil!) . Add the citric acid or the ~juice or the ~slices in detail as the yeast nutrient salt to the mash cooled down to about 25 °C.
The pure culture yeast 3-5 days before in 0, 25l apple juice multiply (see note), because the pure sugar solution of the mixture only difficult to ferment.
Ferment everything together like a wine in a balloon with a fermenter.
After about 2 weeks, drain and pour back into the balloon once more, cool and continue to seal with the fermenting cap. Either on the spot or after self-clearing, add sugar, about 30g per liter.
This results in 6-6, 5 bar overpressure in the sparkling wine bottle with perfect fermentation.
This initial wine is then mixed with a new pure yeast, which in turn was propagated 0.25 liters of apple juice only a few days earlier, and poured into sparkling wine bottles (see note).
The bottles are stored at a heat around 20 °C and briefly shaken once a day.
After 3-4 weeks, fermentation should be complete. The bottles are placed neck down (preferably in a crate or possibly a cardboard box) and transferred to the cellar.
From now on, by daily jerky movement, try to keep the yeast settling on the bottle wall until the st.