Lowtech Graph lists low-tech options for every need of a home. Here you can compare them, find tutorials to build them, and link them together into a circular system. Why low-tech?

Boiling-water bath preserving (pasteurisation)

Passive

One of 3 ways to meet this need. Cost, carbon, footprint and rankings are relative to other solutions for the same need, not absolute.

What your site needs

None.

Jars of fruit, jam, pickles, juice or acidified tomatoes heated in boiling water for a tested time, then sealed as they cool. It keeps acid foods for months at room temperature with nothing but a large pot. It is safe for acid foods only: vegetables, meat and other low-acid foods need a pressure canner, because boiling does not destroy botulism spores.

Cost

Low

Upkeep

None

Skill to build

None

Lifespan

The pot and jars for decades; the lids or seals are replaced.

Embodied carbon

Low

Space / material use

Low

Output timing

On-demand/controllable

Skill to repair

None

Inputs

• Fresh or perishable food
• Cooking heat

Outputs

• Preserved food

Compare the 3 ways to meet this need

Levels are relative to the other options for this need, not absolute. Fewer dots is lighter.

• Boiling-water bath preserving (pasteurisation) (This page)
  Can I use it? Works in a flat · No rebuilding needed
  What does it cost me? Upfront cost: Low · Skill to build: None · Upkeep: Light · Change to daily life: Occasional · Works without the grid: Yes
  Choose it if you want fruit, jams and pickles to keep for months with just a large pot.
• Solar dryer (dehydration)
  Can I use it? Works in a flat · No rebuilding needed
  What does it cost me? Upfront cost: Low · Skill to build: Basic · Upkeep: Regular · Change to daily life: Occasional · Works without the grid: Yes
  Choose it if you want fruit, vegetables or herbs to keep for months with no running cost.
• Pressure canning / autoclave sterilization
  Can I use it? Works in a flat · No rebuilding needed
  What does it cost me? Upfront cost: Medium · Skill to build: None · Upkeep: Light · Change to daily life: Occasional · Works without the grid: Yes
  Choose it if you want cooked dishes and vegetables to keep for months at room temperature.

Sources

• National Center for Home Food Preservation (University of Georgia), "Ensuring Safe Canned Foods"

Limitations of this page

We don’t list sizing or quantities, as the yield of each technique depends on the quality of its build. The catalogue compares options but doesn’t dimension them. Regulatory notes are indicative, with a French example, and need to be confirmed locally.