Put the Toddy in a garrafao or buao and place a burning baked red tile in it.
Or for the second method, place a dark red/black burnt kakond in it.
Cover the buao for a minimum of 22 days and upto a month untouched.
After a month you will see a whitish, greyish film on the top. Remove it with a strainer. Do not use your bare hands.
The kakond also floats on top. Remove that too. Or the tile which is immersed.
Taste and check for sourness. The longer you keep the tile or the kakond in it, the sourer the vinegar will get after fermenting. This vinegar matures with time.
Once ready use a cup to remove it out and bottle it. Never use bare or wet hands.