It needs to be cooked ahead of time so that the flavors are blended and you can taste it and make sure it’s how you want before canning. With the big pot for canning, I have a quilted hot pad under them instead of a rack. I never bought a rack because the hot pads work just fine. You need something under the jars but it can be as simple as a kitchen towel (I have not broken a jar in 3 years! So it must be okay, lol). I have some posts on the water bath method that explain my equipment in more detail.
Sterilize the jars and lids in boiling water for at least 5 minutes. Pack the salsa into the hot, sterilized jars, filling the jars to within 1/4 inch of the top. Run a knife or a thin spatula around the insides of the jars after they have been filled to remove any air bubbles. Wipe the rims of the jars with a moist paper towel to remove any food residue. Top with lids, and screw on rings.
As you will notice when we dive a little further into these recipes, Mexican food has a stunning range of somewhat special ingredients. From Masa Harina, the essential ingredient of corn over a wide array of chilies either fresh, dried or ground to Mexican oregano and tomatillos. Some of these may at first glance seem foreign and difficult to come by, but fear not we’ll discuss the individual ingredients as we go and they’ll be easier to come by than you think.