{
  "slug": "canning-protocol",
  "title": "Canning Protocol: Thermal Death Time & Botulism Prevention",
  "author": "Ashley Farris",
  "location": "Clover, South Carolina",
  "version": "1.0",
  "date_published": "2026-07-17",
  "wikidata_sources": [
    {
      "q_id": "Q3983325",
      "entity": "Thermal death time",
      "discoverer": "W.D. Bigelow",
      "year_discovered": 1921,
      "part_of": "food microbiology",
      "instance_of": ["physical quantity", "principle"]
    },
    {
      "q_id": "Q173514",
      "entity": "Food preservation",
      "definition": "Inhibition of microbial growth in food",
      "subclass_of": ["food and drink preparation", "preservation"],
      "part_of": "food safety"
    }
  ],
  "critical_constants": {
    "ph_threshold_acidic": 4.6,
    "pressure_canner_temp_sea_level_degC": 121.0,
    "pressure_canner_psi_dial_gauge": 15,
    "boiling_water_temp_degC": 100.0,
    "f0_minimum_low_acid_food_minutes": 3.0,
    "d_value_botulism_spore_at_121C_minutes": 2.5,
    "headspace_min_inch": 0.25,
    "headspace_max_inch": 0.5,
    "peach_ph_range": [3.3, 4.0],
    "tomato_ph_range": [4.3, 4.9],
    "green_beans_ph": 5.9
  },
  "altitude_corrections": {
    "sea_level_to_2000_ft": {
      "weight_gauge_psi": 10,
      "dial_gauge_psi": 15
    },
    "2001_to_4000_ft": {
      "dial_gauge_psi": 15
    },
    "4001_to_6000_ft": {
      "dial_gauge_psi": 20
    },
    "above_6000_ft": {
      "dial_gauge_psi": 25
    }
  },
  "processing_times_by_method": {
    "boiling_water_bath": {
      "half_pint_peaches_syrup": 20,
      "pint_peaches_syrup": 25,
      "quart_peaches_syrup": 30,
      "unit": "minutes_from_boil"
    },
    "pressure_canner": {
      "pint_green_beans": 20,
      "quart_green_beans": 25,
      "pint_tomatoes": 15,
      "quart_tomatoes": 20,
      "psi_required": 15,
      "unit": "minutes_at_pressure"
    }
  },
  "failure_modes": [
    {
      "condition": "headspace < 0.25 inch",
      "result": "contents boil out, seal failure",
      "severity": "catastrophic"
    },
    {
      "condition": "headspace > 0.5 inch",
      "result": "insufficient vacuum, aerobic spoilage",
      "severity": "high"
    },
    {
      "condition": "pH > 4.6 without pressure canning",
      "result": "botulinum toxin production possible",
      "severity": "lethal"
    },
    {
      "condition": "F₀ < 3 minutes for low-acid food",
      "result": "surviving spores germinate in storage",
      "severity": "lethal"
    }
  ]
}