You may can plain hot chile peppers. This is useful when you have an overload of them from the garden or find a “too good to say no to” deal at the market.
You can use jars of these in spicy soups, adding the broth from the jar as well. Or, you can drain, chop and add to refried beans, dips, casseroles, etc. They are also good in rice dishes: add at the start of cooking.
They are very fast to use, as there is no rehydrating or thawing required, so you can use them on the spur of the moment.
Jar size choices: 125 ml (1/2 cup / 4 oz) OR quarter-litre (1/2 US pint) OR half-litre (1 US pint)
Processing method: Pressure canning only for plain; water bath or steam canning for pickled
The two smallest size jars can be the most useful. Given the potential heat of some hot peppers such as naga (ghost) or habanero, it can be rare that you get the chance to use a whole half-litre (pint) jar at once and escape unscathed from the loved ones you just fed.
You can can them in three ways:
See the above links for canning directions that apply identically to both sweet and hot peppers.