Kanji is made in ceramic or glass containers, in the sun. It takes about a week to get the right fermentation for carrot kanji here, in Seattle. We don't always have sunlight in the North west and so the flavors can be mild.
It has a distinct, pungent, sour taste usually made in northern India during winters. Adding a little beetroot can give the right color of black carrots usually found in India. Every now and then I do see dark-colored carrots at PCC and Whole Foods which would be ideal to make this drink.