Kombucha is a fermented green or black tea drink. You need to start with a little leftover kombucha and the kombucha "mushroom" (a pancake like thing that is formed at the top of the kombucha as it ferments). I bring some water and sugar to a boil, add the tea bags and let it steep until it's room temp. Then I add the leftover kombucha liquid and mushroom. The yeasts and bacteria eat the sugar and you are left with a tangy drink full of B vitamins and enzymes. Great for digestion. Supposed to be good for weight loss too. I let mine ferment for at least 2 weeks (usually longer). By about 4 weeks, almost all the sugar is gone. I only use a little bit (maybe 2 ounces) since it's so strong (very vinegary) and mix it with sparkling water and a squeeze of liquid stevia. I figure a glass full with the sparkling water and kombucha mix is about 3 carbs (maybe less).
You can buy kombucha on Ebay for cheap. I love it. I crave it too. It's great after a meal, or if you have some indigestion.

Good to know about the swiss chard chips. Can't wait to try that too!