Hello, your pre-culture cant survive in wine if ethanol content equals or above 5.5%. For initiation of acetic acid fermentation you can take fresh portion of grape without washing grand it and add portion of water ( 20% water from grape weight), and wait without addition any yeast for fermentation. In this case 90% you will receive acetic acid fermentation and you can acetic acid fermentation smell.

Than you can partially add your vinegar fermentation solution to this fermentation for receiving acetic acid.

Hope this info will help you.

Vinegar is an aqueous solution of acetic acid and trace chemicals that may include flavorings. Vinegar typically contains 5 - 20% by volume acetic acid. Usually the acetic acid is produced by the fermentation of ethanol or sugars by acetic acid bacteria . From the stoichiometry of the equation it is apparent that 1 litre of ethanol should produce 1.036kg of acetic acid and 0.313kg of water. The slight increase in volume that occurs during fermentation in the range of 1..... For more details consult https://books.google.com.ng

You can try to make your system anaerobic and add bicarbonate (>6g/L) to allow acetogenic bacteria to use ethanol as substrate for acetate formation:

"It has also experimentally been described that A. woodii requires very high HCO3−concentrations of a minimum of 60 mM (optimum, 120 mM) to grow with ethanol as the substrate (76)."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4959221/#!po=0.328947

You will have to make sure it has an acidic pH (4.5-5.5) to avoid formation of other fatty acids or methane.

I hope this works.

Cheers

If you work with acetic acid bacteria do not create anaerobic conditions for fermentation as they are obligate aerobes and will not reproduce without oxygen.

For Acetic acid bacterial growth you need the wine ethanol concentration to be less than 10% (around 6-8% is good). Dilute the wine with distilled water to get to this level. The other thing they need is a stable temperature of 30-34C and good relative humidity. The final thing the bacteria need is oxygen. If you are using lots of sugar then yeast fermentation may be encouraged which will make your media anaerobic and kill the AAB. Rapid shaking (=>160 rpm) on an oribital shaker or pump air into media with a scinter to get the best results. Oxygen is critical and you need to make sure they have enough.

Try to not use more than 20g/L glucose if you have too, but its not necessary as AAB use ethanol as their preferential carbon source. You may need to add nitrogen as, preferably, a mix of amino acids and ammonium ions and vitamins to get maximum acetate production

To speed up your acetic fermentation.

Recipe

5 % alcohol cider 1 liter

4 % unpasteurised vinegar 100 ml

Brix of cider is not below 10 and temperature 30 to 35

And contious aereation either place in luminar flow how and cover the container with cloth. Process duration 20 days ..you acetic acid content will be more than 4 %

The process