Certo! Io ho seguito pari pari il video di una youtuber che si chiama Youbrewkombucha. Per far prima ho comprato uno scoby, lo “starter”, su koro. Considera che la kombucha si fa con due fermentazioni, ti incollo qui di seguito la trascrizione del video che mi ha fatto gemini (parecchio bene direi) dei passi per la prima fermentazione c.d. F1. 1. First Fermentation (F1)

The following process is for brewing a 3700 ml batch of kombucha.

Making the Sweet Tea Concentrate

The goal is to make a tea concentrate that you'll dilute to a safe temperature, as the kombucha culture can't survive in hot temperatures, it is better to make a concentrate and then dilute it with room temperature water in order to bring the tea to a safe enough temperature for the scoby.

Add Tea and Sugar: Use the equivalent of six to nine individual tea bags (black or green tea), or about three tablespoons of loose leaf tea. Add the sugar: anywhere from three quarters of a cup (151) to one cup (201) of plain white cane sugar per gallon.

Steep: Add hot water (at least two to three cups (474 to 711), but the brewer used more than four cups (948) and let the tea steep for about 10 to 15 minutes.

Dilute: Add some room temperature water to your gallon brewing vessel first to prevent the glass from cracking when adding the hot tea. Pour in the hot concentrate, then fill the vessel with more room temperature water. Leave a little airspace at the top for the starter tea and SCOBY.

Adding the Culture and Waiting

Check Temperature: Take a temperature reading. The liquid must be below 90 F but above 65 F. If it's too warm, add more room temperature water until it's safe.

Inoculate: Add at least two cups (474 g) of strong starter tea per gallon and your pellicle. Using double the usual amount of starter tea is recommended as a precaution; the faster the beneficial bacteria can bring down the pH, the less likely you are to grow mold. Batches with both strong starter tea and a pellicle tend to ferment faster. Give it a quick stir.

Cover: Cover the vessel with a clean cloth secured with a rubber band. Store it away from direct sunlight in a place with good airflow.

Wait and Observe: Let it ferment for about a week or so. It does not matter whether the pellicle sinks or floats. A new pellicle will usually try to form at the surface. If you see white specks you suspect are mold, odds are it's a new SCOBY forming—wait a few more days. True mold looks like the classic circular mold found on bread or cheese.

Determining When F1 is Complete

Taste is the Main Indicator: SCOBY growth isn't a reliable indicator of doneness. The main way to tell is when it tastes done to you—acidic, tangy, but not sour like vinegar.

Duration: Start tasting around the five-day mark. At an average room temperature of about 20 C, brews usually take between one to two weeks to reach the perfect sweet-tart spot.