Canning & Bottling: The Complete Walkthrough
This guide covers canning & bottling, rated a moderate task, typically taking 2–4 hrs/batch.
This is the expanded version of our canning & bottling guide, for anyone who wants the full detail rather than just the quick-reference card.
Heat-processed and sealed
Canning works by heating filled, sealed jars enough to destroy spoilage organisms and create a vacuum seal as they cool — done correctly, this makes produce genuinely shelf-stable for a year or more.
Before You Start
A few things matter most here:
- Mason-style jars with new lids
- A water bath canner (for high-acid foods) or pressure canner (for low-acid foods)
- A jar lifter and canning funnel
- A tested, reliable recipe/process for the specific food
The Method
The key things to get right:
- 1. Use a tested recipe appropriate to the food's acidity — this determines whether water bath or pressure canning is required.
- 2. Sterilise jars and prepare produce according to the recipe.
- 3. Fill jars, leaving the correct headspace, and remove air bubbles.
- 4. Wipe rims clean, apply lids, and process in the canner for the specified time.
- 5. Cool, check seals (lids should not flex), and label with the date before storing.
When Things Go Wrong
A few things matter most here:
- Jars don't seal — check for nicks on the jar rim, insufficient processing time, or old lids; reprocess or refrigerate and use promptly instead.
- Cloudy liquid or floating produce — often cosmetic rather than unsafe, but check the seal and smell before use.
- Low-acid foods processed in a water bath — a genuine safety risk; low-acid foods (most vegetables, meat) require pressure canning, not water bath.
- Mould or off smell on opening — discard without tasting; when in doubt, throw it out.
Keeping It Going
Best time — at the peak of each crop's harvest, when there's a genuine surplus to preserve. Duration — each batch takes a few hours; properly sealed jars keep 12+ months in a cool, dark cupboard. Maintenance — check stored jars periodically for seal failure or spoilage signs. Signs of success — a firm, sealed lid that doesn't flex when pressed, and clear (not cloudy or bubbling) contents.
That's the full walkthrough. The printable A4 quick-reference card for this is on the main guide page below.