Continuous Brew Kombucha: The Complete Guide

Continuous brew trades the batch rhythm for a tap: a bigger vessel that stays mid-ferment permanently, drawn down and topped up on demand. It is how many daily kombucha drinkers escape the Sunday afternoon of bottling, jars and sticky counters - and it changes the math from "how much for a batch" to "how much for a draw". The continuous brew calculator sizes draw and refill; the batch-level fundamentals stay in the kombucha sugar guide.

How the vessel works

A continuous brew is a large vessel - 5 to 15 liters for most kitchens - fitted with a spigot above the yeast sediment line. You draw finished kombucha from the tap and pour fresh sweet tea in through the top; the SCOBY and the mature, acidic liquid left in the vessel are the starter for every refill. There is no day 1 and day 7 anymore, just a rolling balance between what you take and what the culture can re-acidify.

The draw-and-refill rhythm

A sustainable draw is 20-40% of the vessel each time. Worked example: a 10-liter vessel drawn at 30% hands you 3 liters, leaving 7 liters of seasoned culture behind. The refill for that draw is fresh sweet tea at the standard batch ratios - 50 g of sugar per liter (150 g here) and about 2 tea bags or 3.7 g of loose tea per liter (roughly 6 bags or 11 g here). Let the tea cool before it meets the vessel, and expect the new fill to taste ready again in a few warm days rather than a full week - the culture starts from far ahead.

Keeping the balance

Two failure modes bookend a continuous brew. Too slow - drawing rarely - and the vessel drifts toward vinegar, the same over-fermentation a batch suffers on day 14. Too fast - drawing deep and refilling often - and each round starts from less acidity, with thin flavor and slow acidification. The rhythm that holds: draw what you drink, refill what you drew, and give the vessel a warm, stable spot. Bottling a draw for fizz runs the same second-fermentation math as always - the second fermentation calculator does not care where the kombucha came from - and the flat-bottle guide still applies when the fizz does not show up.