Mom is right. Listen to your mom, LOL. It is normal.

Here's an answer posted previously by Linda Lou:

Why does home canned tomato juice usually separate?

Home canned tomato juice usually separates because it is made by the "cold break" method. The tomatoes are crushed before they are heated through. As soon as they are crushed, enzymes start to break down the pectin that "cements" tomato cells together. Commercially, tomatoes are heated nearly to boiling in a matter of seconds, using equipment not available to consumers. Because the pectin holding tomato cells together remains intact, a thick bodied, homogeneous juice is produced. The best that can be done at home is to heat quartered tomatoes quickly to boiling temperatures while crushing. Make sure the mixture boils constantly and vigorously while you add the remaining tomatoes. Simmer 5 minutes after all tomatoes are added, before juicing. If you are not concerned about juice separating, simply slice or quarter tomatoes into a large saucepan. Crush, heat and simmer for 5 minutes before juicing.

Barbara Willenberg, Nutritional Sciences, University of Missouri-Columbia.

I have some jars of whole tomatoes, or rather parially whole. I removed some of the seeds and water, as well as peeled them. I packed them in a thick tomato sauce. The result was a thick jar of big chunks of tomatoes with no water settling on the bottom.

Does making homemade spaghetti sauce have the same separation problem?

Not usually if its made with tomatoes that are more meat than water, like many plum types. A beefsteak, for instance would not be a good sauce tomato. You do need to cook the sauce down a bit, so it thickens. In this way the liquids will not seperate out.

I use whatever kind of tomato I have on hand for tomato sauces and haven't ever had problems with separation.

Carol

There shouldn,t be separation when canning sauce as the liquid will have evaporated during reduction.

I had this happen with a batch of tomato sauce last week, which is the first time in hundreds of jars over several years. The only difference was I added paprika directly onto the frying garlic, which caused it to scorch, versus the usual method of adding the paprika after I've sauteed the onion and pepper along with the garlic. Busy giving my DD18 a demonstration in how I make the sauce, which she discovered is somewhat better than the stuff they serve at her school, and is getting a twinkling of interest in what the old duffer gets up to, so of course I botched something up.

Anywho, a dozen quarts of separated sauce. I'll shake them before cooking with them.

David, your using an oil to saute.. This can be dangerous if added to home canning. No home caning is very safe if an oil is present in the mixture. A very small amount like less than a teaspoon for a 7 quart batch might be fine.

"No home caning is very safe if an oil is present in the mixture."

Just a reminder that there are a few tested recipes with oil that are safe, like the marinated peppers.

And of course oil in limited amounts may be present in pressure-canned foods like meats.

Carol

When my grandmother canned juice she used to let it sit for a while until it seperated, skim the thin juice off and can it seperately. We kids loved to open a jar of the thin and drink it cold.

Janet

Yes, that tomato water is served at very fancy restaurants as a separate, pricey item.
By discarding it, you lose a lot of the goodness of the tomato. I find that shaking the jars of tomato juice a few times after they cool, minimizes the separation. And you can always shake it just before you open the jars.

No, I have a huge, 14 inch non-stick frying pan that sautées the stuff before I can it. It also tastes better to add olive oil and the other spices when we actually plan to heat and serve it.

However, re botulism toxin, we always boil the tomato sauce anyway for at least 15 minutes to destroy any possible toxin.

Last year I had almost 200 tomato plants and this year I will have more.

Where can I get the commercial tomato juice equipement with the flash heating? Has anyone tried making a homemade version of the equipement?

Do you have many thousands of dollars to spend on flash processing? They are not cheap and are the most costly device to run and maintain for any canning company. For extracting juice from tomatoes, there are several choices and some are a few hundred dollars or more starting with the Spremy which is motorized with conical screens. Adding a little acid to the juice can allow it to be home canned in quarts, provided its processed long enough. 200 plants yielded me about 60 quarts of sauce, but I did give many tomatoes away too. Depending on the type of plants and how much they produce, you can expect a big variable when it comes to the end result of filled jars. In some areas of the country, there are community kitchens that allow people to home can their produce. In those cases, the canning is done in metal cans sometimes, as opposed to glass jars.

I've done both. The "cold break" method and the home flash heating as described by Linda Lou via Readinglady (above). The cold break always yielded a sauce that separated for me and the home flash heating has consistently yielded a sauce that didn't break. I usually have a large stock pot of tomatoes heating. That way - whether it be for sauce or stewed/diced tomatoes - the product won't 'float'. If you can peel, slice/dice and drop the tomatoes directly into a pot of already boiling tomatoes (except of course for the first round) then there shouldn't be a problem. My husbands aunt prefers the efficiency of cold pressing and doesn't mind the floating sauce at all. It doesn't impact the taste.

Cindy

What works for me is my 23 quart pressure cooker/canner. 2 cups of water and the canner rack. Put in your whole or cut tomatoes (do not crush the tomatoes!). Cook at 15 pounds for 10-15 minutes. Then juice or seive as normal.
When canning, return the juice to the pot, bring to a boil, then simmer for 10 minutes before jarring.

I cut the tomatoes in quarter and salted them leaving them in a strainer for 45mins then ran them through the mill . I ended up with thick sauce and less liquid.