No, it is not safe to can your own recipes. That is one of the number one safe guidelines. ( I teach food preservation safety.) You not only cannot safely determine the ph at home (we HIGHLY discourage trying this) nor the density. The density is just as important when factoring a safe recipe for canning. Please, find a recipe that is close in the Ball Blue Book or one of the extension recipes and follow it. You can safely add any dried herbs or spices to change the flavor. When you can foods the starting ph level will not necessarily be that later on as it sits in the jars. The ph does change.

Another favorite is Sharon's (Chase) Tomato Sauce. Posted by Chase - Recipe Exchange Here are two recipes I use. I can mine but it may be frozen or just made up for a meal. Divide the recipe as required. Plain Italian Tomato Sauce 24 cups smooshed tomatoes whirred smoothish * 2 cups finely minced celery 2 cups finely minced onion 1 1/2 cups finely minced carrot (use just one for a bit less sweet I use 1 1/2) 12 TBSP bottles lemon juice 2 TBSP coarse salt Note: For one batch I sub hot peppers for some of the carrot and celery, just so I have a piquante sauce as well. Herbed Tomato Sauce 24 cups smooshed tomatoes whirred smoothish * 4 - 5 cups chopped herbs of your choice 12 TBSP bottled lemon juice 2 TBSP coarse salt. I use Basil, oregano and parsley but you can use only one or two or three and you don't need to use equal amounts, in other words you can go 2/3 basil 1/3 parsley. For all of them bring to a rolling boil and then lower heat to a high simmer , you want to see some action but not a full boil. After coming to the boil a foam will form, skim it off. Place your jars in the dishwasher , when the jars are done so is the sauce. I generally cook about an hour , you can go longer. I don't like to cook less than an hour 'cause I want some thickening to take place while canning so it doesn't need to much cook time when I use it. Fill jars as normal. HWB for 30 minutes. * I break the tomatoes with my hands and then use a hand blender to smooth some more. You could use a food processor. I do not seed my tomatoes but you could. Other Notes: You can vary the amounts of each of veggie (celery, onion and carrots) as long as the end result does not exceed 5 1/2 cups of veggies to 24 cups of tomatoes. Some commented that they would cut down the carrots (too sweet) and increase the onions by that same amount. These and some others are posted on the Bernardin website (linked below) - the Canadian division of Jardin/Ball/Kerr. Here is a link that might be useful: Bernardin Tomato Recipes

There are many approved (as in tested for safety) BBQ sauce recipes. As Linda Lou said try any of the canning cookbooks or NCHFP - linked below - or the Ball website, or homepreserving.com for starters. If you use one of the approved recipes for canning then you can always add the pineapple juice and bits at food prep time. And in some cases, since the pineapple juice is so acidic you can sub some of it for the other liquids called for in the recipe. What makes a cooking recipe unsafe for canning is that you cannot know the pH or the density of it so you can't determine a method of processing or a time for processing. Safe canning recipes always include that information. Recipes that include all sorts of low-acid foods like onions, garlic, peppers, fresh herbs, etc. require sufficient acid to be added to make them safe for shelf storage in an anaerobic environment. Note how much more vinegar is called for in the NCHFP Bar B Q Sauce recipe than in the one you linked. Ball also has a good recipe for Bar B Q Sauce that calls for 1/3 c lemon juice and you could easily use pineapple juice instead. Hope this helps. Dave Here is a link that might be useful: NCHFP

I tinkered with the NCHFP recipe and it came out pretty good. I did a blog post about it in January with the basic recipe and my tweaks and tricks if you're interested. Here is a link that might be useful: Homemade Barbecue Sauce