Homemade Canned Ketchup

I made this recipe last Friday; this is my first summer ever canning and I have want to can so many things.  I really would like to can some tomato salsa, but I need to fulfill my curiosity of canned ketchup and barbecue sauce first.  I bought Ball's Complete Book of Home Preserving this spring and that is where I found the recipe; the recipe is also on their website:
 http://www.freshpreserving.com/recipe.aspx?r=137

Also, I halved the recipe and I ended up with about 4 1/2 pint jars.  This ketchup is delicious and my 6 year old said he loves it so much more than store bought ketchup.  It did take most of the day to make from start to finish but a lot of that time is letting it simmer and stirring occasionally.  I'll be making ketchup again next year!

Ingredients for a half recipe:

This is how I measured out 24 cups.

1 1/2 Tbsp celery seeds
2 tsp whole cloves
1 cinnamon sticks, broken into pieces
3/4 tsp whole allspice
1 1/2 cups cider vinegar
12 lb tomatoes, cored and quartered (about 36 medium, I measured out 24 cups)... NOTE:  If you peel your tomatoes they will be much easier to sieve/run through a food mill.  {Thanks Anonymous Commenter below!}
1 1/2 cups chopped onions (about 4 medium)
1/2 tsp cayenne pepper
3/4 cups granulated sugar
1/8 cup salt
5 (16 oz) pint glass preserving jars with lids and bands

Process:
1. TIE celery seeds, cloves, cinnamon sticks and allspice in a square of cheesecloth, creating a spice bag. (I just tossed all of these into the saucepan and strained them through a thin dish towel after the 25 minutes had passed.)

Seasonings steeping in the vinegar.

Straining seasonings with
towel and small colander.

2. COMBINE vinegar and spice bag in a stainless steel saucepan. Bring to a boil over high heat. Remove from heat and let stand for 25 minutes. Discard spice bag.

It was a VERY full pot and
this is the largest stainless pot I have!

The tomatoes and onions cooked for 20 minutes,
just before adding the vinegar.

3. COMBINE tomatoes, onions and cayenne in a clean large stainless steel saucepan. Bring to a boil over high heat, stirring frequently. Reduce heat and boil gently for 20 minutes. Add infused vinegar and boil gently until vegetables are soft and mixture begins to thicken, about 30 minutes.
4. TRANSFER mixture, working in batches, to a sieve placed over a glass or stainless steel bowl and press with the back of a spoon to extract all the liquid. This can also be done using a food mill. Discard solids.
5. RETURN liquid to saucepan. Add sugar and salt. Bring to a boil over medium heat, stirring occasionally. Reduce heat and boil gently, stirring frequently, until volume is reduced by half and mixture is almost the consistency of commercial ketchup, about 45 minutes.
6. PREPARE boiling water canner. Heat jars and lids in simmering water until ready for use. Do not boil. Set bands aside.
7. LADLE hot ketchup into hot jars leaving 1/2 inch headspace. Remove air bubbles. Wipe rim. Center lid on jar. Apply band until fit is fingertip tight.
8. PROCESS jars in a boiling water canner for 15 minutes, adjusting for altitude. Remove jars and cool. Check lids for seal after 24 hours. Lid should not flex up and down when center is pressed.