DemijohnHome wine, mead and cider
Your batch log, with the maths built in.
Demijohn keeps every batch, reading and addition, and works out the numbers from them: ABV that stays right after a step feed, temperature-corrected gravity, the dose for what is really in the carboy, and a warning before a mistake.
- No account
- No subscription
- Works offline
- OG
- 1.110
- Now
- 1.040
- ABV so far
- ≈ 10.5 %
- Attenuation
- 64 %
Next Rack at 1.010 or lower
Free calculators
The same maths as the app, in your browser. Nothing you type leaves the page.
- ABV from OG and FGStandard and alternate formula, temperature correction, step feeds.
- How much sugar or honeyFor a target gravity or potential alcohol, with the new volume.
- Hydrometer temperatureCorrect a reading taken warm or cold, 60 °F or 20 °C hydrometers.
- Gravity scales and tableSG, Brix, Plato, Oechsle, Babo, Baumé, with potential alcohol.
- Mead for beginnersHoney for your batch, nutrients in steps, finishing and bottling.
What it does
Every batch on one timeline
Kit wine, fresh grapes, fruit wine, mead, cider and perry. A day counter, the stage, and the next step, which can wait for a date or for a gravity reading.
A reading in two taps
A keypad made for gravity numbers. Temperature correction runs as you type, and ABV and attenuation update with every reading.
Calculators that know the batch
Open a calculator from a batch and it is already filled in with its volume, last gravity, pH and ABV. One tap writes the dose back into the log.
Warnings before the mistake
Sorbate with malolactic bacteria, sulfite near the legal limit, sweetening before stabilising. “Looks finished” and “may be stalled” come from your own readings.
The gravity curve
Every reading on one chart with the target finish band, additions and rackings marked. Smooth with years of batches.
A checklist before bottling
Gravity stable, malolactic done, stabilised, free sulfite, carbonation within your bottle’s limit. Worked out from the log, each line with its reason.
Free
- Unlimited batches, readings and notes, never capped
- Every batch type and template
- The full gravity chart, all warnings and the bottling checklist
- ABV, temperature correction, refractometer, every gravity scale
- Sugar or honey to a target, sulfite, sorbate, backsweetening, priming
- 3 reminders and a home-screen widget
- One-file backup and restore, a printable batch sheet
- Light, dark and high-contrast themes
Pro
- Molecular sulfite from pH
- Acid up and down, blending (Pearson square and more batches)
- Fining and bentonite rates, tirage planner by bottle type
- Nutrient planner that times the doses and sets the reminders
- Bench-trial helper for backsweetening
- Batch comparison and trends
- Unlimited reminders, CSV export, extra themes
Pro is one payment. No subscription. Try it free for 7 days. When a trial ends, every batch stays readable, editable and exportable.
Your batches stay on your phone
Demijohn has no account and no server. Batches, readings and reminders are saved on your phone and nowhere else. The only network traffic is Google Play or the App Store when you buy Pro.
Who makes it
I’m a solo developer and I build small offline apps under the name Mufatech. I read a few hundred reviews of winemaking and mead apps and a lot of forum threads, and built the batch log people kept asking for. Questions or a number that looks wrong: hello@mufatech.com.