To prevent contamination, which will ruin your batch of Kombucha, it is very important to prepare the tea and ferment it in a very clean environment and use clean equipment, including the vessel to boil water, any spoons used to stir the sugar or tea, the glass containers used for fermenting and storing, and anything used for straining the tea.
Wash your hands with hot soapy water before starting, and wipe down with vinegar all counters where you'll be working.
Do not smoke cigarettes and tobacco around the Kombucha fermenting area. Even better, don't smoke in the same house. Smoke molecules will kill or weaken the culture.
Although the kitchen seems like the most convenient location for storing jars of fermenting Kombucha, it's best to find another spot. Smoke from cooking, burning fats, and other particles are not hospitable to Kombucha. Bathrooms and kitchens harbor the most bacteria, wild yeast, molds, and germs, because of their work surfaces, sink drains, toilets, and food.
Keep your jars of fermenting Kombucha away from plants. The soil contains millions of spore and microbes per inch, spores that can become airborne. It's best to keep plants in a different room.