Kombucha Sweet Tea (Base Formula)

This is the standard first-fermentation (F1) sweet-tea formula that the kombucha method runs on. It fixes the sugar, tea, and starter ratios so every batch begins acidified and ferments predictably to a 2.5-3.5 pH endpoint.

Characteristics

Property	Value
What it is	Sweetened tea, acidified with mature kombucha, fermented by a SCOBY
Sugar	50-75 g white sugar per liter (60 g/L default)
Tea	5-7 g loose black or green tea per liter
Starter	10-20% mature kombucha by volume (15% default)
Starting pH	below 4.5 (target 4.2 or lower)
Finished pH	2.5-3.5
Best for	a clean neutral base to flavor and carbonate in F2

The formula (per liter)

The reliable home ratio, by volume and weight, per 1 liter of finished sweet tea:

• Water: ~850 mL (you make up the balance with starter)
• Sugar: 60 g (white granulated)
• Tea: 6 g loose leaf (about 2-3 bags), steeped 5-7 min, then removed
• Starter: 150 mL mature kombucha (15% of the 1 L total)
• SCOBY: one healthy culture per vessel

Ratio shorthand: ~60 g sugar : 6 g tea : 15% starter per liter of total liquid.

Scaling table

Columns are batch vessels: 1 Jar = ~1 L, 2 Jars = ~2 L, 1 Crock = ~4 L, 6 Crock = ~24 L. Grams/mL are per the whole batch; sugar and tea hold the per-liter ratio, starter stays at 15% of total volume.

Component	1 Jar (1 L)	2 Jars (2 L)	1 Crock (4 L)	6 Crock (24 L)
Total liquid	1,000 mL	2,000 mL	4,000 mL	24,000 mL
Water (approx.)	850 mL	1,700 mL	3,400 mL	20,400 mL
Sugar	60 g	120 g	240 g	1,440 g
Loose tea	6 g	12 g	24 g	144 g
Starter (15%)	150 mL	300 mL	600 mL	3,600 mL
SCOBY	1	1-2	1-2	several

Note

Scale by volume, but watch surface area: kombucha is aerobic, so wide vessels ferment faster than deep ones of the same volume. A 24 L crock with a narrow mouth will lag a set of jars holding the same liquid.

Calculated values

• Sugar concentration: 60 g/L = 6% w/v at the start; most is consumed by the finished brew.
• Starting pH: 15% mature starter (pH ~2.5-3.5) into sweet tea reliably lands the start below 4.5 — confirm with a meter.
• Target finished pH: 2.5-3.5, at which point reserve 10-20% as the next batch’s starter before bottling.

Caution

The 10-20% acidic starter is the safety control, not a flavor tweak. It must bring the start below pH 4.5 (target 4.2 or lower) before fermentation begins, so mold and pathogens never establish. Never start a batch with sweet tea alone. Confirm the start and the endpoint with a calibrated pH meter — taste is never a safety test. See Acidity and pH.

Variations

• Green-tea base: swap black for green tea at the same 6 g/L; expect a lighter, slightly faster brew. For a honey base on green tea, use the dedicated jun method and culture, not this formula.
• Stronger / lighter: push sugar toward 75 g/L for a fuller, more acidic finish, or down toward 50 g/L for a lighter one. Do not drop below ~50 g/L — the yeasts need the fuel.
• Continuous brew: in a spigot crock, draw off finished kombucha and top back up with fresh sweet tea at the same ratio, leaving the SCOBY and a large acid reserve in place.

🫙 Kombucha method

🛡️ pH safety calculator

See also

• Kombucha method — the full F1/F2 workflow this formula feeds
• Jun — the honey-and-green-tea variant
• Acidity and pH and Sugar in fermentation