It could  be very dangerous getting recipes from the internet unless you are sure they are research based from a reliable source.  Spaghetti sauce with onions, garlic and peppers needs to be pressure canned.  The reason is that you are mixing high and low acid foods together and want to be sure it is processed long enough to destroy the spores of Clostridium botulinum.  If they are not destroyed then your sauce could cause very serious food borne illness.

I suggest you go to the OSU Extension FCH website and download the Canning tomato publication.  It has both spaghetti sauce with meat and without.  The website is http://extension.oregonstate.edu/fch/fppd-preservation.  The publication is PNW 300 Canning Tomatoes and Tomato Products.  Another reliable website is the National Center for Home Food Preservation http://nchfp.uga.edu. 

All home canned tomato products whether canned in a water bath or pressure canner are acidified with either bottled lemon juice or citric acid.

If you have other food preservation questions you might like to call the OSU Food Preservation Hotline which is now open M-F 9 a.m. - 4 p.m. through mid October Certified Master Food Preservers are available to answer your questions. The number is <personal data hidden>.

Thanks for using Ask an Expert.

Nellie Oehler