Woad Vat Know

Woad Vat is an offline-first indigo and woad fermentation tracker for natural dyers, historical textile workshops, and home vat keepers who must confirm true reduction before the next dip—so cloth is not ruined by guesswork. Cold start opens a fullscreen active vat-card: liquor color chip (yellow-green when reduced), reduction ready or not-ready status, last-stir and last-feed timestamps, pH band, temperature band, flower or scum note, and a one-tap dip-test strip. You run one working vat at a time on the live card and lock liquor state, feeds, and dip results in one glanceable surface—not a generic hobby journal. Log reduction feeds with typed recipe presets (classic bran-madder, fructose, iron, soda-ash notes) and editable ingredient lines locked to the current vat. Record dip sequences with expected versus observed liquor color, cloth sample name, immersion count, and post-oxidation blue reading as typed fields. Keep a chronological feed and stir timeline (feed, stir, skim flower, rest) with free-text bench notes, plus separate morning and evening day-diary checklists for smell, bloom, and sediment. Name and park older vats in a multi-vat archive (volume, vessel, start date) while only one remains the live card. Search Room-backed history by fabric name or feed type across archived dip strips. Export a plain-text vat summary—recipe plus recent events—to the clipboard for studio notebooks. Three seed demo vats (fresh set, mid-reduction, exhausted) show a real working card on first launch. Preferences cover pH and temp unit display, stir reminder interval labels (local only), and card density. No cameras, sensors, or network. Built for dyers who need locked reduction chemistry on one offline card before they commit fabric to the liquor.