Vinegar (usually cider vinegar) sugar. The toms can be bagged and frozen whole. They are usualy run through a food strainer to remove skins and seeds. Once thawed from the frozen state, the skins are waasy to remove. It is difficualt to determine how many pounds to use as the all toms contain water, whicb adds a LOT of weight to tomatoes. Plum and paste type tomatoes have less water, while slicing and eating types usualy have more. In any case, its a good idea to try and remove most of the excess water and some seeds. You can do this by simply cutting each tom in half, and dig out most of the watery liquid and seeds. It doesnt need to be totally cleaned out, but will offer a thicker end product (more pulp) that would require less cooking down. Once you remove the water and seeds, then bag them for the freezer. Just do the toms that are very ripe and hold off on any that are not quite ripe yet. I use the Roma/Villaware food strainer for all of mine, and it gets every single seed and skins. The Roma is nice, as it doesn't need any prepping except for removing most of the watery liquid inside. Estimate the amount once its been deseeded and skins are removed. Because of water in the pulp, its difficult to know how many to use, but prepare more than enough for the ketchup recipe, and the rest can be made into a sauce, and canned or frozen.

I used the ketchup mix, and the instructions are as follows.
6 lbs fresh tomatoes (about 18 medium)
1 cup white vinegar
1 (6oz)can tomato paste
1 1/2 cup granulated sugar
1 pouch Mrs. Wages ketchup mix

wash tomatoes. cut out cores, remove skins and seeds. crush tomatoes one layer at a time with potato masher. in large saucepan, bring crushes tomatoes to a boil. stir frequently. reduce heat & simmer for 25 minutes.

combine juice, tomato paste and vinegar in large pot and bring to a boil. stir frequently. slowly add sugar and ketchip mix to hot juice until evenly dispersed. reduce heat and simmer 5 minutes.

pour hot sauce into clean, sterilized pint jars, leaving 1/2 inch head space. cap each jar when filled. process 40 minutes in bwb.or you can also freeze.
hope this helps.

Thanks! You've both been very helpful!

The cider vinegar is also used by many commercial ketchup makers. The white distilled vinegar has a more distinct vinegar flavor that takes away tomato taste, while cider vinegar is more mellow. If you like hot spicy, add a little cayenne for the last bottle or two. I always like to adjust flavors when making a complex mix like ketchup. Things like allspice, onion, and garlic are good. I would add dried types of herbs and spices to reduce the liquid, and taste while adding things. I made a chunky ketchup once with mincd peppers and onions. Its not as easy to pour out and was spooned instead. The use of a 'spatter screen' on the top of the pot will help to reduce big hot globs from popping out of the pot when it boils, as its very thick and when boiling its a real mess around the stove without one.

Good ideas, I'll use some of those next time I make ketchup.

I've been wanting to make ketchup for years, and just yesterday purchased a package of Mrs Wages Ketchup mix. I do have a question though. I would like a smooth ketchup. This recipe has you blanch, core, seed, and then crush tomatoes. Is there any particular reason I can't just cook the tomatoes first, then put then thru the food mill to remove seeds, skins, and make a smooth ketchup? That would be easiest - obviously. Or - if that is not realistic, - any reason why I could not use an immersion blender on the tomatoes after cooking them for 25 minutes? The NCHFP recipe calls for peeling and coring, but uses a food mill after the tomatoes are cooked to remove seeds and make a smooth product. Thanks for any input. :)

<Is there any particular reason I can't just cook the tomatoes first, then put then thru the food mill to remove seeds, skins, and make a smooth ketchup?>

No reason that I know of. Might have to cook it down a bit more to get the consistency you want.

Dave

Thanks Dave!!! I was thinking it would be fine - just needed a little confirmation. :)