Home canning, with the tested source printed next to the claim

Home canning has one genuine failure mode, and it is not a jar that tastes wrong. It is a jar that looks, smells and tastes exactly like every other jar on the shelf and contains a toxin produced by Clostridium botulinum. That failure mode is rare, and saying so is not a softening — it is the reason the subject can be discussed calmly. What it does mean is that the difference between a good page and a confident, wrong one is not a matter of taste.

There is a body of research-tested guidance that answers most of the question, it is free, and it is online. So the easy thing for a site like this to say is that the canning blogs are all wrong and the official guidance is right. This site does not say that, because it is not true and you would find it out within an afternoon. A number of pages written in 2025 and 2026 quote the National Center for Home Food Preservation accurately. At least one manufacturer publishes processing tables that match the USDA guide exactly [F-15.2]. The picture is better than it was, and a site that opened by telling you otherwise would have printed a disprovable sentence in its first paragraph.

The harder problem is the one underneath. The tested guidance is itself scattered, dated, and in several places contradicts itself in public. The USDA Complete Guide to Home Canning is a fixed document, last revised in 2015, and it says steam canners are not currently recommended because the research was unfinished. The National Center for Home Food Preservation — which maintains that guide — published the finished research the same year and said yes, with conditions [F-6.2]. Its own "Equipment and Methods Not Recommended" page now carries both texts: the superseded sentence standing directly above the update, and a plain statement that working the change into the printed guide will take time [F-6.4]. Nobody is lying, nothing has been withdrawn, and both texts are live today. The whole argument is laid out on steam canning: what changed, and when, which is the clearest single case of it. It is not the only one. The guide says unused lids are good for five years and, with one sentence between them, to buy only a year's worth [F-8.2]. The dial-gauge processing tables stop at 8,000 feet [F-4.2], and the numbers in circulation above that come from somewhere else entirely.

So the gap is not someone who knows the rules. It is someone who knows which text is current, what it actually says, and where it runs out. That is what this site is. Every page prints the document it is quoting, the page or section within it, and the date somebody last opened that document and checked the quote still reads that way. Where two tested sources disagree, both are shown, dated, with no attempt to smooth them into one voice. Where nobody has run the research, the page says nobody has run the research, which is a more useful sentence than a confident guess and is harder to write.

What this site does not do: it publishes no processing times, pressures or headspaces of its own. Not one. When you need a number, a page here will name the tested document that holds it and link you to it. Two reasons, and both are practical. A site that retypes somebody else's tables becomes a place where a single typo can hurt somebody, and it has nothing to offer that the original does not already have — the tested tables are free, maintained by the people who ran the research, and better than anything that could be built on top of them. What is missing from the internet is not another copy of the tables. It is a straight account of which copy to trust and when it was last checked. How this site works sets out the standards in full, and sources lists every document the site rests on with its date.

If you are starting from nothing, begin at start here — the first page is the one number that decides everything else. If you arrived because two pages told you opposite things, where the guidance stops is the section written for you.