Companies like Ball have tested their recipes and have altitude charts for processing, so you can be assured that if you follow their instructions, your product will be safe.
So, once you have your recipe and understand how to process it correctly and safely, you'll probably go through a process similar to this.
Step 1: Getting started. You'll need the following supplies:
- At least 3 very large bowls.
- Two to three pots for blanching
- Hot pads & apron
- A large slotted spoon
- A couple of plastic sacks
- A pairing knife
- Stock pot
- Pressure canner or water bath canner, depending on recipe
Step 2: Pick and wash your tomatoes. Make sure you select firm, ripe (but not overly ripe) tomatoes. Discard any diseased tomatoes.
Step 3: Stem and prep the tomatoes by cutting out any bad parts. I like to stem before blanching because the fruit is firm and it's less messy. One time-saving tip I learned is to put all the stems and discarded parts into a double-bagged sack in the adjacent sink. This really helps minimize the mess.
Step 4: After all the tomatoes have been washed and stemmed, set them aside in a large bowl. It's now time to prep for blanching. Quickly scrub out your sink again and fill one side with COLD water. Also, keep that double-bagged sack handy. You'll need it again for the skins.
Step 5: Blanching means to dip the tomatoes into very hot, nearly boiling water for a minute or two so that the skins will crack and will easily slip off.
I've learned a few tricks to blanching. First, I've found that it is better to use more than pot so I can blanch several loads at once. Also, it takes longer to heat up a really full pot than 2-3 or partially full pots. Second, I've found that doing step #3 and step #5 at the same time, in an effort to multitask, is chaotic unless you have someone helping you.
So, get your water nice and hot first and then pop the tomatoes in.
Step 6: Using your slotted spoon, pull out the tomatoes when the skins begin to crack.
Step 7: As I pull the blanched tomatoes out of the hot water, I place them into a large bowl and then quickly transfer the tomatoes to the sink filled with COLD water. You don't want the tomatoes to continue cooking and to get mushy; that would make skin removal more difficult.
Step 8: As soon as the tomatoes cool enough that they can be handled, begin slipping off and discarding the skins. Once again, using the double-bagged discard sacks is handy. I take this time to look over the tomatoes one more time, looking for any defects that need to be removed.
Step 9: Before you begin the salsa-making part, scrub out the pots you've used and clean out your sink again. It's much easier to deal with the mess as you go than to deal with it all at the end.
Now the tomatoes should be ready for salsa making (or bottling them if you just want stewed tomatoes). Here's a tip: Don't waste your time chopping them up. With clean hands, just squish them to oblivion. It won't matter in the end.
Step 10: Now follow your tested recipe exactly. Proper acidity needs to be maintained, so you shouldn't add or omit ingredients, change quantities, or make substitutions. Doing those things could alter the acidity and make the product unsafe. If you don't like the way a recipe tastes, find another recipe; don't try to fix it.
Step 11: My recipe calls for cooking the salsa. I really need to invest in a stock pot, but I've found that using my roaster over two hot elements works fine.
Step 12: If you want to thicken the salsa more quickly, dip a strainer into the pot and spoon off some of the juice. You can freeze it and use it in taco soup later.
Step 13: When the salsa is nearly ready to be put into jars, warm the rings and lids in a pot. Don't boil them.
Step 14: Fill your jars, wipe the rims, and affix the lids and rings.
Step 15: Process according to the proper method and for the proper time. Pressure canning and water bathing are NOT interchangeable methods. If the recipe you are using calls for pressure canning, do it! Most likely your recipe will call for water bathing, though. Be sure to adjust processing times for elevation as per the published instructions.
Step 16: After processing, make sure they have properly sealed before you store them. The lid, when sealed properly, should not make a clicking sound when pressed. Don't stress out if the lid is still clicking after you've pulled them out of a water bath canner. It sometimes takes a bit before they seal. You'll hear a **POP** when it seals, and after it does, the lid will no longer click when pressed.
If the jars are completely cool and the lid didn't seal, you either need to reprocess immediately or store the jar in the refrigerator and use its contents soon. Jars that have not been sealed properly should not be stored at room temperature.
After the jars are totally cooled and lids checked for proper seal, the rings can be removed and the jars stored at room temperature. Be sure to date and label each jar.