Start Here
Which method your food needs, what you actually have to buy, how to read a tested recipe, and the one number the whole decision rests on.
6 pages here.
Six pages, in order. If you read them in order you will have the whole decision in your head before you open a jar, and you will be able to tell a page that has read the tested guidance from one that has read another page that read it.
Here is the short version of all six, so you can skip to the one you need.
Every food you might can sits on one side of a single number: a pH of 4.6 [F-1.1]. Below or at it, boiling water is enough. Above it, boiling water is not enough at any length of time, because the thing that has to be destroyed is destroyed by temperature and boiling water cannot get hot enough [F-1.2]. That is page one, and everything else follows from it.
The equipment you need is smaller than a listicle suggests and more specific than a general-purpose pot. There are two real constraints: a boiling water canner has to be deep enough [F-2.1], and a pressure canner has to be big enough [F-3.1]. Page two is those two constraints and what they rule out.
Then a tested recipe, which is a document with a particular anatomy, and altitude, which changes the schedule inside it. The tested sources will not give you a number until they know your elevation, and the USDA guide will not even publish a lookup table of elevations — it says plainly why not [F-4.5].
What is not here. This site publishes no processing times, pressures or headspaces of its own, on purpose. When you need one, these pages will tell you which tested document holds it and link you to it. A site that retypes somebody else's tables is a site where one typo can hurt somebody, and it has nothing to offer that the original does not already have.
-
Water bath or pressure: the one number that decides it
The choice is not about jars, batch size or how long you have. It is a pH of 4.6, printed on one page of the USDA guide, and this page quotes it, gives the page number, and explains what it means for your food.
-
What you actually need to buy, and what you do not
Every item here is justified against something the tested guidance requires — the depth of the canner, the capacity of the canner, the gauge that creates an annual job, and the one grocery item that is really a piece of equipment.
-
A tested canning recipe is a document with a fixed anatomy: jar size, pack style, headspace, canner, process time, altitude adjustment, and a source you can open. Here is what each part is doing and which parts you are allowed to change.
-
Your first batch, start to finish, without a recipe
Everything around the schedule: choosing a tested recipe, water depth, preheating that is not sterilising, what to do when the boil stops, the five minutes before you lift the jars, and the twelve to twenty-four hours after.
-
The words: process, headspace, siphoning, vent, seal
Five words that do the heavy lifting in every canning instruction, defined from the guide's own glossary, plus the two terms that quietly decide whether a page you are reading is trustworthy.
-
Altitude: find yours first, because it changes the rest
Water boils cooler as you go up, so every tested schedule is written in altitude bands. Here is why the USDA guide refuses to publish a list of elevations, where to get yours, and which band structure applies to which kind of table.