Canning Timer
Water-bath or pressure canning timer that adjusts process time or target pressure for your altitude, with a full-boil confirmation gate before the countdown starts.
Built by the AbraCalc team
How to play
- Choose your method: Water Bath for high-acid foods like pickles and jams, or Pressure for low-acid foods like vegetables and meats.
- Set your jar size and enter your altitude in feet — the process time (water bath) or target pressure (pressure canning) updates automatically.
- Confirm the checkbox once your pot is at a full rolling boil or your canner has reached and held target pressure — this unlocks Start Timing.
- The fullscreen countdown runs the adjusted process time; when it reaches zero you'll get a distinct alarm and next-step guidance for your method.
Canning at altitude is one of the few kitchen tasks where getting the numbers wrong is a genuine food-safety problem, not just a texture issue. Thinner air means water boils at a lower temperature, so both water-bath processing time and pressure-canner PSI need to go up the higher you are. This timer applies standard altitude bands — no adjustment under 1,000 feet, then step increases up to 10,000 feet — to your jar size and method, and won't start the countdown until you confirm the pot has actually reached a full rolling boil or the canner has held its target pressure. It is a timing and reference aid for a recipe you already trust, not a replacement for one.
Frequently asked questions
- Why does altitude change the processing time or pressure at all?
- Water boils at a lower temperature as altitude increases, so a pot at a full rolling boil is actually less hot the higher up you are. Water-bath recipes compensate by processing longer; pressure canning recipes compensate by raising the target pressure instead of the time, since the pressure itself is what raises the effective temperature inside the canner.
- Can I just use this timer instead of following a tested canning recipe?
- No. This tool applies standard altitude-adjustment bands to a base process time, but the base time itself has to come from a tested, current recipe for your specific food, acidity, and jar size — sources like the USDA Complete Guide to Home Canning. Use this timer to track the clock and get the altitude math right, not to invent process times from scratch.
- Why can't I start the countdown right away?
- Canning process times only count from the moment the water is at a genuine full rolling boil (water bath) or the canner has reached and held its target pressure — starting early undercounts the actual processing time your jars receive. The confirmation checkbox is a deliberate gate so the timer can't start on a pot that isn't there yet.