Honey Kombucha (Jun) Calculator

How much honey, tea, water, and starter do you need for an N-quart batch of jun (honey kombucha)? Inputs scale the textbook 70 g/L honey + 5 g/L tea + 15 % starter recipe; output is honey weight (g, oz, tbsp), tea weight, hot-steep water, cold top-off water, starter volume, expected fermentation timeline, and target finish pH.

2.0US quarts (1.89 L)
0.5 qt (test)2 qt (½ gal)8 qt (2 gal)
Sweetness target
Tea

Steep at 75–80 °C (do not boil — bitter) for 5–7 minutes, then strain.

Starter share (mature jun from prior batch)
Honey required
132g
(4.7 oz · 6.3 tbsp)
Stir into hot tea while it's still > 60 °C so it dissolves cleanly, then cool the must to < 30 °C before adding the starter and SCOBY.
Tea, water & starter
9.5
Tea (g) · ≈ 4.7 bags
402
Hot steep water (mL)
1207
Cold top-off water (mL)
284
Starter (mL) · ≈ 1.20 cup

Order of operations: steep the tea in the hot water (5–7 min), pull bags / strain, stir in honey while still hot, top off with cold water to cool the must below 30 °C, then add starter + SCOBY. Cover with breathable cloth, ferment 21–26 °C out of direct sun. Honey volume itself ≈ 93 mL — the cold top-off already accounts for it at this batch size.

Fermentation timeline at standard sweetness. 5–8 days at 21–26 °C — textbook jun window — start tasting day 5, bottle when pH hits 3.0–3.2. Target finish pH 2.8–3.2 (start ≈ 4.0–4.5 with 15 % starter). A pH below 2.6 has gone past kombucha into vinegar territory; above 3.5 it's underfermented and may be unsafe to bottle. Use 0.1-resolution pH strips or a meter, not taste alone — the sweetness can mask the acid early. Bertelloni 2022, Coton 2017.
Method. Honey grams = total_volume_L × honey_concentration_g_per_L; tea grams = total_volume_L × tea_concentration_g_per_L; water = total_volume − starter. Standard concentrations: 70 g/L honey + 5 g/L green tea + 15 % mature jun starter (Crum & LaGory 2016, The Big Book of Kombucha). The 25 % hot-water split is a practical heuristic: enough hot water to fully extract the tea polyphenols and dissolve the honey, with the cold top-off rapidly cooling the must to a SCOBY-safe < 30 °C — avoiding the "poured boiling tea on my mother" mistake that kills new brewers' cultures.

Jun is not sugar kombucha. Pour honey into a sugar-adapted SCOBY and the brew usually stalls — honey's residual peroxide + lower available nitrogen disadvantages the resident Komagataeibacter / Brettanomyces consortium. A true jun mother (purchased or gifted from another jun brewer) is honey-adapted and ferments cooler (21–26 °C vs. 24–29 °C) and faster (5–8 days vs. 7–14 days) than kombucha. Don't substitute; use a real jun starter. Marsh 2014; Coton 2017; Bertelloni 2022.

Planning tool, not a yield guarantee. Real fermentations vary ±1 day on timeline and ±0.2 pH at finish depending on starter health, ambient temperature, honey antimicrobial load (manuka honey notably suppresses jun fermentation — stick to clover, wildflower, or orange blossom for first batches), and SCOBY generation. For commercial jun brewing, calibrate against your own pH log across at least three batches.

Honey Kombucha (Jun) Calculator — rawhoneyguide.com