Tomorrow is the first day of September, and with it comes all those traditional end-of-summer events, including tomato canning season (at least here in the mid-Atlantic where I live). Because the yearly tomato glut is finally beginning to arrive, I’ve been getting a number of questions about how to safely can tomatoes.
The most frequent question I get is from people wondering if they can boiling water bath process their favorite spaghetti sauce recipe. You know, the kind that has plenty of garlic, onions, basil, olive oil and sometimes even a few peppers.
Sadly, I always end up delivering disappointing news. You really can’t just can your family recipe. Anything canned in a boiling water bath needs to be high acid (for the science minded types, this means that it has to have a pH of 4.5 or below). This is because botulism cannot grow in high acid environments. However, tomatoes are in the grey zone, typically having a pH right around 4.5. Because of this, tomatoes need to be acidified when canned, so that the acid levels are pushed into the safe zone and the pH becomes something lower than 4.5. That’s why my instructions (and all other good ones you’ll find) for canning whole tomatoes includes two tablespoons of bottled lemon juice per jar (you can also use citric acid if you prefer).
When you make spaghetti sauce, one typically adds a slew of ingredients that, while delicious, lower the acid to seriously unsafe levels. Unless your family spaghetti sauce recipe contains several cups of red wine vinegar, it will be too low in acid to be canned in a boiling water bath.
Most canning information will repeatedly remind you that it’s incredibly important to follow tested recipes. While I will occasionally play around a bit with jams and pickles (and I only do this because I know which aspects can’t be monkeyed with), even I never deviate when it comes to acidifying my tomatoes. I always follow the instructions in either the Ball Blue Book or So Easy to Preserve when I want to preserve tomato sauce, soup and salsas.
The one caveat I have to offer is that if you have a pressure canner, you may be able to preserve your beloved sauce recipe (just so you know, any recipe that includes meat MUST be pressure canned). Pressure canners raise the internal temperature of your jars to temperatures in the neighborhood of 240 degrees, which is high enough to kill off any botulism spores that may exist in your food. However, you should still consult recipes that have been tested using a pressure canner to determine processing time and pressure.
The good news here is that there are plenty of safe, tested tomato recipes that are designed for canning. Let’s hear about your favorites!
I bought a canning PH meter this year. I’d like to be sure my food is safe when Im canning. I picked it up on Amazon. It has a few packets for calibration of the meter before using it. You mix the powder with distilled water . I plan on using it next year when I can my tomato sauce, pears, salsa, apple pie filling and jams. I love my canned food. My boy friend loves salsa, we put up 23 quarts this year. UGH! I love him so why not dip a monitor in each jar to protect is tummy LOL
You are so wise!
Thank you Marisa, I really appreciate the reply and I sure dont want anyone to get sick. I have disposed of what I had already but will be making new and will definitely be doing the water bath method and I also thank you for the link.
Much appreciated.
Can tomato paste be added to sauce to thicken for water bath canning.pizza sauce? Does it increase or decrease acid level
It’s typically not a great idea to add something to an already formulated recipe. It probably wouldn’t make it unsafe to add tomato paste, but I cannot fully anticipate what it would do to the acid content.
Why do you use bottled lemon juice instead of fresh lemon juice?
Answer here: https://foodinjars.com/blog/canning-101-why-recipes-call-for-bottled-lemon-juice/
Hello,
I have subscribed to your site and I have a question. I have made some sauce using San Marzano tomatoes, crushed and peeled, and used Garlic, salt and pepper and a pinch of sugar. I washed the jars in the dishwasher using the Sanitizer Cycle. While sauce was still on the stove simmering and the jars finished, I took a jar out one at a time while still hot and put the simmering sauce in. I immediately put the lid on and tightened. I let them sit on my table overnight to cool and the lids had “pinged”.
Might this be acceptable or should I throw them away and use the boiling method? Also, adding lemon juice, how might this affect the flavor when used?
What you’re describing is the open kettle method. It isn’t recommended in the US as a safe canning technique. I’d open the jars, reheat the sauce, and fill clean, hot jars with the reheated sauce and process according to the timing recommended for that product. I’d also add some lemon juice or citric acid, as recommended by the National Center for Home Food Preservation. Here’s their page on canning tomato sauce. https://nchfp.uga.edu/how/can/how-do-i-can-tomatoes/standard-tomato-sauce/
my question is about lids . can I can my food using a lug lid ? can I do it for water bath canning ? and can i use it for pressure canning ? and if not why not ? so many people have said no to pressure canning but they dont supply a answer as to why not ? the cans we see in the stores are lug lids .how are they processed if not by pressure caning ? plus -how long are these lids good for ? i know this is a lot but we had a shortage a few years back and then china sold america canning lids and they was sub par ! they didnt can as good they used too .if you can answer those questions ,i will be happy. thank you
I bottled 30 pint jars of pasta sauce. After a few weeks it was tested for pH levels which read 5.1. I did not use lemon juice. I then dumped all the sauce back into the pot and reheated it adding real lemons rather than bottled lemon juice. It now has a reading of 4.9. I used 7 lemons to the whole batch
Surprisingly it still tastes like pasta sauce. Should I throw it out or can I now add 1TBsp. Bottled lemon juice to each pint jar and continue. If so, do I sterilize the jars and then fill them with hot or boiling pasta sauce and prep the for the water bath, boiling the filled jars for 10 minutes. Do I need to pour hot pasta sauce in sterile jars again? Or can it be cool sauce in non sterile jars or sterile jars?
You want the pasta sauce to have a pH of at least 4.6 and ideally a little below that. I would keep acidifying and testing until you meet that threshold. Whenever you do recan the sauce, you need to proceed as if it is the first time you are canning it. Hot jars, hot sauce, new lids, etc. Processing time for quarts is at least 40 minutes, with more if you are at higher elevations. Consult the National Center for Home Food Preservation website for your appropriate processing times. https://nchfp.uga.edu/how/can/how-do-i-can-tomatoes/standard-tomato-sauce/
I wasn’t able to grow this year but would still like to make tomato based sauces and soups. Can I use plained canned tomatoes from the grocery store to make home canned soups and sauces?
Yes. Best to use whole peeled tomatoes as they are the least processed and will hold up the best. Just know that your finished products might separate a little because the tomatoes will have been cooked twice and that breaks down their pectin. But you can shake it to reintegrate.
I made a spaghetti sauce that has oil in it.
I processed the sauce in my processor for 60 min like recipe called for.
However when it was done the water in the processor was red ,like some of the sauce leaked out Do you think this safe. The jars are sealed. I have 6 quarts
Did you follow a recipe from a reliable source? If so, it should be fine. Some siphoning is normal during processing.
I canned spaghetti sauce with store bought tomato sauce and hamburger. I used a pressure cooker. Will that be alright to eat?
It is only safe if you followed a recipe from a reliable source!
I used freeze dried garlic in a tested canning pizza sauce recipe and used lemon juice in some jars and citric acid in others and processed the recomm ended time for my elevation are my jars safe?
That sounds okay to me.
I canned some tomatoes chicken soup and I ran out of water so the soup scorched. Can I open it …reheat and let it boil for 20 minutes and recant it or is it okay to eat as it is?
I could smell it burning so I slowed down the heat…. But did not open it or add water but brought the heat up again and finished the 1hr…15 min process
Did you use a pressure canner? This one sounds like a loss, at least to me.
Best I can tell, there are literally zero 100% “safe” canning recipes for anything, there are only “statistically safe” recipes. Which are statistically safe is dependant on who is making the determination and setpoint. In other words, what’s considered safe in one country may not be in another. E.g. one piece lids are considered unsafe for canning in the usa, but are preferred in the EU. Really, it is about which techniques were tested and how, but the usa hasn’t done an update in like 60 years. Regardless, can enough of anything any which way some will be unsafe, it’s just a matter of how many. Could be 1/999999999999999999999999999999.the really tough part is that the recipes don’t tell you the actual danger measured, and we don’t even know their sample size… so a “safe” recipe unfortunately is still highly subjective… why trust the USA but not Japan or the UK guidelines? Doesn’t it matter?
Can I safely omit onions and garlic from a recipe for bbq pork, and still pressure can according to directions?
Yes. Leaving out those ingredients doesn’t change the safety of the recipe.
I have a number 10 can of Ketchup , can I re can it in small jars?
Recanning commercially preserved products isn’t typically recommended.
hi, just found your article. And I’m just hoping you can clarify some questions for me. My family has been making tomato sauce for like 200 years. We still pretty much use the same recipe in the same process except now we have more modern equipment, our sauce, tomatoes olive oil, garlic and basil. Then after it’s cooked, put into a water bath to boil and then they covered them with blankets for days. maybe I misunderstood but what you’re saying is that this is not safe?
According to currently safety standards, that is not a safe approach at all. Our understanding of food safety has evolved quite a bit over the last 200 years.
Hi there
. I use tomato sauce in cans and then add my own ingredient. I want to make a big batch and then can it in jars. If I pressure can them will it be safe to eat as long as I add a teaspoon of lemon juice to each quart?
I recommend consulting the National Center for Home Food Preservation to determine the steps for your product. Without knowing what you put it in, I cannot advise.
https://nchfp.uga.edu/how/can3_tomato.html#gsc.tab=0
I want to can a low salt taco sauce that went over big in my family. I used commercial canned diced tomatoes, tomato sauce and tomato paste, plus a couple of table spoons of vinegar and sugar and spices. Can I do this safelyusing my hot water canner?
Unfortunately, I can’t determine something’s safety for canning from a list of ingredients. I’d suggest you find a taco sauce that’s safe for canning and tweak it to meet your needs.
Can i make my spaghetti sauce today and can tomorrow
You can, though know that tomato products can sometimes separate when you heat, cool, and then heat them again.
I canned marinara sauce for the first time this year. I went by the directions and water bathed the cans for the fire the appropriate time given.It’s lot of work to can home made sauce. My marinara now has the white film on top of the sauce. What has happened?
It sounds like it might be mold. When in doubt, throw it out.
I made a large batch of tomatoe sauce, added 2 tablespoons of lemon juice to each jar, HOWEVER, added veg oil (just enough to fry up) with onions and garlic. Processed 40 minutes. Should I waste this?
When it doubt, throw it out.
I have learned so much from this post – thank you! But I have now realized I made a big mistake. I canned my family recipe of spaghetti sauce (full of lots of different veggies like onions, carrots, zucchini, peppers…) in a water bath and without any citric acid 3 days ago. It’s been sitting in the pantry. Should I discard it or would I be able to put it in the fridge or freezer?
You could open the jars, boil the contents hard for 20 minutes and then freeze the sauce. That would be the only way I’d recommend to salvage the product. If it’s very thick, add some water before boiling to ensure that it doesn’t burn.
I forgot to add citric acid to 4 qurts of homemade spaghetti sauce, however, I made said sauce in my pressure cooker, but canned it using stove water bath. Will the sauce be okay if I store the 4 quarts in the fridge?
Yes. If you store them in the fridge, they will be fine.
I have a canning recipe foe tomato sauce but i make mine with beef bones. Can I still water bath?
No. The beef bones will lower the acidity and render it unsafe.
Hi. Regarding all these questions about recipes etc. and the addition of lemon or vinegar: Why not just test the pH of the finished sauce? There are general guidelines I follow, and the pH is always around 3.6. Never above 4, and 4.6 is the max. you’d want. Since published recipes can be all over the place regarding ratios of tomato/onion/peppers, I’ve found this to be much easier and pretty much worry free. And of course don’t include chunks of low pH fruits/vegetables/meats.
pH strips are cheap and take the mystery out of it.
thanks
Brian
There are a couple reasons why it’s not recommended that you just test the pH. The first is that pH testing strips aren’t always perfectly accurate. The second is that pH can change a bit over the life of the product.
I have a recipe for enchilada sauce that I’d like to can. It has chicken broth, spices and tomato paste in it but I can’t find out how to pressure can it safely. The only canned enchilada sauce recipes start with dried peppers and/or tomatoes. My sauce is quite mild and not so complicated. I’d like to make a huge batch and can it in quart jars. Any advice? BTW I have some ph test strips for kombucha and beer making so they are food safe. Thanks
You could probably use the pressure canning times for chicken stock, since that’s probably the lowest acid ingredient present. But as always, it’s better to use a tested recipe rather than guestimate your way to a solution.
Can you can tomato sauce in half full jars in a pressure canner
No. The jars have to filled properly or you risk spoilage.
I fell in love with pressure canning this year snd would love to can my family recipe as follows
1 store bought cans tomato purée (plain) add 2 cans of water from
Puree cans
2 store bought canned tomato paste adding 4 cans of water from
Paste cans
In a pot simmer garlic in a bit of olive oil. Add tomato product and water, lemon juice for acid.
We do cook it with meat (pork and meatballs) but I would can the sauce separately
I would pressure can it. Is this safe and what processing time would it call for if it’s safe at 10 pounds pressure
I’m so sorry, but I can’t advise on specific recipes. I suggest you take a look at the National Center for Home Food Preservation website and see if they have something similar posted.
I’m making lemon marinade and then changing it to a roasted habanero finishing sauce. I let it seal as I do jams in hot jars and lids. I’m sure it has enough acid from the lemons. To be sure it’s safe I’m going to pressure cook all the 1/2 pints. Most don’t have a 1/2 ” of head space. Can I stack them in the pressure canner?
I’d put a rack in between the layers to prevent the jars from tipping. Otherwise, your plan seems sound.