Choose what you're fermenting, fill in your batch details, and calculate. This is a working guideline from studio field practice, not a lab-calibrated or food-safety instrument — always taste, smell, and look before you trust a number here. Once a wine or kombucha batch is bottled, the Shelf Life & Storage Calculator can help you think about how long it keeps.
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Choose what you're fermenting and fill in your batch details to see salt, sugar, and timing here.
Drink Theory Studio
Field notes
Salt percentage is the real control
Everything else about a vegetable ferment — texture, speed, safety margin — follows from getting the salt percentage right. Too little and spoilage organisms can outcompete the lactic acid bacteria you want; too much and fermentation slows to a crawl. The ranges here are a starting point, not a guarantee.
Kombucha strength is a trade, not a target
A longer first ferment trades sweetness for tartness and, eventually, acidity that can taste more like vinegar than tea. There's no universally "correct" F1 length — only the point where it tastes right to you, which this tool can only estimate toward. Want to measure and adjust that acidity precisely once it's brewed? The Acid Adjustment Calculator picks up from here.
A hydrometer beats a guess, every time
Potential ABV, sugar additions, and dry vs sweet finishes all depend on an actual starting gravity reading. Fruit type, ripeness, and growing conditions vary far too much for any tool to estimate sugar content from a fruit name alone — the Himalayan Pantry is a starting point for getting a feel for a specific fruit or botanical before you ferment it.
Grains are alive, not an ingredient
Kefir grains grow, get sluggish in the cold, and speed up in the warmth — the amount and timing here are a starting point for one batch, not a fixed recipe. Watch how your particular grains behave and adjust from there.
What this tool cannot know
It has no idea what's actually happening in your jar today — trust your taste, smell, and eyes over any number here. See the safety note below for exactly what to check before you trust a batch.
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Your Field Log
Nothing saved yet. Calculate a batch above, then choose "Save to Field Log" to build a running record on this device.
Compare two saved entries
Pick any two saved Field Log entries — the same ferment type or different ones — to see the delta in their key numbers (salt %, sugar %, days, hours, or potential ABV, whichever apply).
Select two saved Field Log entries to compare their key numbers.