"YeasTea", get it? It's tea fermented by yeast!
Now I am aware that kombucha is also a yeast fermented tea drink too; kombucha is actually what made me think about throwing some yeast into a pitcher of tea to start with. While both drinks do involve yeast and tea, YeasTea differs from kombucha because the kombucha culture is a symbiotic mass of multiple yeast strains and species of acetic acid bacteria, which results in the final drink having little to no alcohol (the bacteria gobble it up) but potentially all sorts of acids, and the YeasTea culture is nothing more than our good friend Saccharomyces cerevisiae, which (despite the fact that I'm using baker's yeast) results in a tea drink that's alcoholic but lacks (for the most part) the same variety of acids found in kombucha.
To make a yourself a batch of YeasTea you'll need the following:
A sanitary glass vessel that can be sealed (I use a boiled mason jar)
A wooden spoon
A candy thermometer
A kettle or other means to boil water
A measuring cup
A 1/2 end volume container to brew tea in (you could just brew the tea in the same glass vessel the drink will ferment in, but I find it easier to use a separate vessel)
1 tea bag/cup
1 tbsp sugar/cup
~1/8th tsp baker's yeast/4 cups
Step 1: Brew the Tea
Boil water and make a batch of tea half the volume of your final intended batch size using 1 tea bag per final batch size cup. So, for example, if you want to make 4 cups of YeasTea, brew a batch of tea using 2 cups of water with 4 tea bags. Let the tea bags steep for between 10-20 minutes.
Step 2: Hydrate Your Yeast (If You Need To)
If you're using dried yeast, while your tea bags still have at least 5 minutes left of steeping to do measure out 1 cup of warm water (I just run faucet water over my hand until it reaches a comfortable temperature to figure out how warm to make it) and mix in your yeast so that there aren't any floating specks left over.
I generally use around 1/8th of a tsp of yeast to make a 4 cup batch of YeasTea, and though I'm sure this volume of yeast will probably be good for larger or smaller batches assuming that the yeast only won't reproduce more than their environment can handle I'm just going to say to use around 1/8th of a tsp of baker's yeast per 4 cups just to be safe.
Step 3: Mix the Ingredients
Once the tea is done steeping (if it's in another vessel) pour it into the vessel you intend to ferment your YeasTea in and then add cool water to it until you reach a volume 1 cup less than your final intended volume. So, for example, if you're making a final batch size of 8 cups take the 4 cups of tea that you now have and add 3 cups of cool water. Now stick your thermometer into the tea and wait until it reads between 98 and 110 degrees Fahrenheit (or between 36 and 43 degrees Celsius) to add your 1 cup of yeast.
Now add the sugar, stir it in with your chosen spoon, and seal the lid on your vessel
Step 4: Ferment!
Stick your vessel someplace warmish and somewhat dark to let it ferment for at a minimum of 3 days, though I generally let it go for between 4-6. If you're using baker's yeast like I did, for the first two to three days the yeast will produce massive amounts of CO2, and though a bit of carbonation in the final product is pleasing I'd advise that you crack the seal of your vessel's lid at least once over the course of these first few days to ensure that too much CO2 doesn't build up in your vessel and dissolve into your drink.
Step 5: Enjoy!
Once your tea is done fermenting place it in the fridge until you're ready to drink it. While (I at least think) it tastes pretty good straight, I generally prefer to flavor my YeasTea with some sugar and some lemon juice or vanilla soy milk as I would a regular glass of tea.
As the second and third picture show, however, adding soy milk to YeasTea causes its fluid components to settle out. While I was a bit unnerved to see my drink do this, the fact that a concoction of vodka, soy milk, and soda I like to drink does a similar separation act makes me pretty sure that this is due to the presence of a minute amount of alcohol in my drink rather than some scary, inadvertently brewed up toxin. Furthermore, I think the fact that I'm still here to write this after drinking several batches solo should support the idea that it isn't poison.
On a final note, I hope it should go without saying that you shouldn't drink the layer of yeast cake at the bottom of the vessel; not only will pouring the yeast cake into your cup probably give your drink a strong, "yeastie" flavor, but in consuming the little guys you won't be able to reuse the yeasties left over to brew another batch of YeasTea.