01
Scale by ratio, not by guesswork
Use fixed per-liter ingredient loads so your recipe behaves consistently at different volumes.
This is the fastest way to avoid weak tea, flat flavor, or under-acidified starts in larger vessels.
Kombucha · Batch Calculator
Kombucha
Batch Calculator
Scale any kombucha recipe from 1L to 25L while tea, sugar, and starter stay perfectly proportional — no guesswork, no weak batches.
Per-liter recipe
6 · 70 · 15
Sugar70 g/L
Tea6 g/L
Starter15%
Multiply each per-liter value by your batch size to scale cleanly. Adjust live below.
Live calculator · updates as you type
Your batch
L
15%
Your recipe
Sugar 350g
Tea 30.0g
Tea bags (2 g)15
Starter liquid750 ml
Top-up water4250 ml
Total volume5.00 L
Tea concentration 6 g/L
Use this as a baseline recipe calculator. Fermentation speed and acidity still depend on SCOBY strength, temperature, and oxygen exposure during first fermentation.
Batch scaling guide
Scale with control, not trial and error.
Use the calculator for exact scaling math, then use these process checkpoints to keep taste and fermentation behavior stable as your batches grow.
Scaling range 1–25 L
Maintain per-liter math so each step-up keeps the same balance.
Core rule Ratio lock
Tea, sugar, and starter stay proportional during scaling.
Best practice Log runs
Process notes catch drift faster than memory-based tweaks.
Scaling formula per-liter × total liters
Keep this constant across every ingredient. If your tea load is 6 g/L and the batch is 8 L, total tea is 48 g.
02
Lock your baseline recipe first
Validate one reliable small batch before scaling so you are multiplying a known-good process.
If the baseline is unstable, scaling amplifies the same issues.
03
Batch size changes fermentation behavior
Larger batches usually have slower thermal swings and can ferment slightly differently than 1L test runs.
Use the calculator as baseline math, then verify with taste and acidity checkpoints.
04
Keep starter percentage consistent
Starter ratio is part of the scaling math, not an afterthought. Keep it proportional to total volume.
Adjust only when needed for temperature or acidity control, and document the change.
05
Track every scaled run
Record room temperature, start pH, sugar profile, and day-by-day tasting notes.
Small process logs make later scaling decisions much more reliable.
06 Checkpoint
Use quality checkpoints at each size jump
Move up in steps, not huge jumps. Confirm taste, acidity, and timing at each new batch size.
When output drifts, troubleshoot process variables before changing your core ratio model.
Download the free Kombucha Brewing Schedule
Printable scaling worksheet with per-liter math, checkpoints, and batch comparison notes.
Kombucha batch-scaling questions
Common questions about scaling tea, sugar, and starter together.
Can I scale kombucha recipes directly?
Yes, as long as tea, sugar, and starter ratios stay proportional to the total volume.
Why does large-batch kombucha taste different?
Thermal behavior and oxygen exposure can shift fermentation speed even when recipe math is identical.
What starter ratio is safe for scaling?
Around 15% is a solid default, with range adjustments based on acidity and ambient temperature.
Should I change tea strength when scaling?
Keep tea concentration steady first, then tune only after tasting the scaled result.
Keep brewing
Continue your kombucha workflow
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