Daily canning output equals the loads one canner can run in a working day times the jars per load times the number of canners, and the load time is the fixed processing time plus the overhead of heating, venting, pressurising and cooling. With an assumed 60 minutes of overhead, quart green beans at 25 minutes take 85 minutes a load, so 5 loads a canner in 8 hours, and 3 canners holding 7 quarts each fill about 105 jars a day.
A canning production timeline is a plan of how many jars of each food can be processed per day and in which weeks, given the canners, crew, jars and lids available.
The Model
For one canner:
cycle time = overhead + processing time
loads per day = whole number of cycles that fit in the working day
jars per day = loads per day × jars per load × number of canners
Processing times are fixed by safety. The carrier’s table at 10 PSI (sea level) gives, for example, green beans 20 min (pints) and 25 min (quarts), carrots 25 and 30, chicken on the bone 65 and 75, and beef or venison chunks 75 and 90 (Canning & Pressure Preservation).
Overhead has a known part and an unknown part. The carrier’s procedure requires venting steam for 10 minutes, then waiting 10 minutes after the pressure has dropped before opening: 20 minutes. The time to bring a canner up to venting, to pressurise it and to let it fall to zero naturally depends on the canner, the fire and the load. It must be measured. The sums below assume it is 40 minutes, so overhead is 20 + 40 = 60 minutes (an assumption, not a source figure).
Jars per load depends on the canner. Many large canners take 7 quart jars at a time; read yours from its rating or count by loading it. The sums assume 7.
Worked Example 1: Quart Green Beans
- Cycle = 60 + 25 = 85 minutes.
- An 8-hour day is 480 minutes. 480 ÷ 85 = 5.6, so 5 whole cycles (5 × 85 = 425 minutes).
- Jars per canner per day = 5 × 7 = 35.
- With 3 canners (the carrier’s “2-3 running at once”), 35 × 3 = 105 jars a day.
- The carrier’s target is 500 to 1,000 quart jars for a winter: 500 ÷ 105 = 4.8, so 5 days at best; 1,000 ÷ 105 = 9.5, so 10 days.
Worked Example 2: Quart Beef
- Cycle = 60 + 90 = 150 minutes. 480 ÷ 150 = 3.2, so 3 cycles.
- Jars per canner per day = 3 × 7 = 21; with 3 canners, 63 a day.
- 200 quarts of meat: 200 ÷ 63 = 3.2, so 4 days.
Meat is slow because the processing time dominates. Do not plan 100 quarts of meat and 100 quarts of beans as if they took the same time.
What Limits The Output
| Limit | Check |
|---|---|
| Lids | One new lid per jar for two-piece lids; reusable lids change this (Preservation Schedule) |
| Jars | Count sound jars, plus spares for breakage |
| Heat | Each canner needs a steady fire or stove for the whole cycle; three canners on wood need a big stack |
| People | A canner needs someone at the gauge for the whole processing time to hold the pressure steady |
| Prep | Washing, peeling, cutting and packing must keep each canner’s next load ready |
| Cooling space | Filled jars cool undisturbed for 12-24 hours; 105 jars a day need table space for a day and a night |
| Water | Hot water for filling, cooling and cleaning |
Build The Timeline Backward From The Harvest
- List foods by the week they arrive (July-September).
- For each week compute the jars you can produce.
- Compare with the produce expected; where the supply exceeds the jars, send the surplus to drying or fermenting.
- Sequence the day: start the longest processes first, begin meat early, keep a steady flow into the canners.
- Write the dates on the calendar and name the pressure-canning operators (Skill-Based Task Assignment).
Altitude
Above sea level, increase the pressure and keep the time. The carrier’s table: 10 PSI at 0-1,000 ft, 11 PSI at 1,001-2,000, 12 PSI at 2,001-4,000, 13 PSI at 4,001-6,000, 14 PSI at 6,001-8,000 and 15 PSI above 8,000 ft. A timeline built for sea level is wrong on a hill farm.
Never trade safety for throughput
If the timeline slips, add a canner, a crew or a day. Never shorten a processing time, skip the 10 minutes of venting, force-cool a canner or open it early, use a water bath for a low-acid food, or fill containers larger than the tested size. A pressure canner is a steam vessel that can scald and burst; inspect the safety valve and vent each season. Botulism toxin gives no warning in the jar, and a swollen lid or off smell means the food is destroyed, not tasted.
Failure Modes
- Counting only process time. Heat-up and cool-down are half the cycle for beans.
- Mixing foods in one load with different processing times. Run each food’s own time.
- Pressure fluctuating because the attendant left the gauge.
- Jars breaking from cold jars in hot water or drafts on hot jars.
- No lids left at the peak.
What’s Next
- Learn next: Smoking and Curing Schedule — the meat stream
- Combine with: Preservation Schedule — the wider plan