Hi Toxie, yes you need to have the pH lower than 4.6, HOWEVER, it is critical to understand two things:
1) Home pH strips of colored paper are not accurate enough. You need the liquid kits and a good quality equipment (droppers etc) to get an accurate reading. This is critical because of no. 2 below
2) The danger of pathogen growth (c. Bot) is tied to BOTH pH and water activity (Aw). So just cause you have a pH lower than 4.6 if your water activity (meaning free-available water) is greater than 0.85 the risk IS STILL THERE. You have to use both in conjunction to statistically prevent c. Bot.
But, all this gets into the scientific micro-chemistry of the subject that gets complicated and is used in the food industry and Federal Regs for consumer safety. We have to have the analytical data to support what we do. You at home do not.
At home, you don't really need to worry about (Aw) if you add the citric acid, and pressure cook to the correct time & temp. And by this I mean that you must use your published guides. Different ingredients may completely skew your cooking time. For instance, if you add bacon bits or grease to your BBQ Sauce, those proteins then require you to treat it as a canned meat in order to ensure safety and canning meat requires much longer temps at higher heat.
Another example. About a month ago my wife canned chicken soup. It had to be pressure cooked 90 minutes at 12 lbs since it had small cubes of chicken in it.
Anyway, I don't mean to scare you off, but canning can be not only dangerous, but deadly if not done properly. So, use the citric, buy the reputable published canning guides (lots are free online from say, Kerr or Ball) and religiously follow the numbers. They have been established in labs and approved for distribution by the USDA.
Yes, once they are canned and cooled (be careful not to tip or jostle the jars until completely cooled) you can put them in the cupboard or basement. Cool dark is best. Once opened they MUST be refrigerated and should last for several weeks in the fridge. In the cupboard prior to opening I see no reason they shouldn't last at least a year, especially if in the basement on shelves. In there they are undisturbed, dark and cool and the only thing past a year is that the product may lose some of its flavor or "punch", that's all.
I'm currently running shelf stability tests on my salsas, and plan to post results after one year of shelf stabillity. I keep them in the basement storage area, a small room with shelving. It stays a steady 50-55 F year round and is usually dark unless we are in there and turn the light on.
Hope this answered your questions and cleared things up a bit!
