Throw on an apron, some opera and a pair of rubber boots ... you're about to learn how to can tomatoes with a tomato press! Plan to set aside 22 mason jars and a day to do this (unless you come from a large Italian family with plenty of helping hands.)
I am on my third batch of canned tomatoes for the year. Because I grow my own tomatoes they don't all ripen at the same time. That means I have to do a few smaller batches of them at the end of the summer instead of one big batch like I would if I was buying bushels of tomatoes at the market.
So, you want to can your own tomatoes too do you? You're feeling like an Italian pioneer are you? Good. Glad to hear it. Pressing and canning tomatoes is a bona fide "thing" and not something you can do without a bit of planning and a bit of know how. Luckily for you ... I'm here to show you how to do it.
I've been pressing my own tomatoes since I was in high school because I had no friends. Because I thought canning tomatoes was fun. Just kidding. I had a lot of friends. They just didn't think I was any fun.
I've always used the recipe passed down from my mother who had it passed down to her from someone else. I used that very recipe right up until the day I realized that recipe could kill me.
For the first decade of making this I just boiled the tomatoes, ladled them into a hot jar and stuck them in a cupboard. That's the way they did it in the olden days and I like to do most things the traditional way. The problem is ... things have changed since the olden days.
Does tomato sauce need to be pressure canned?
Tomatoes have changed since the olden days. They've been "improved" and tweaked and hybridized to within an inch of their lives. This tomato mutation has caused the pH level of tomatoes to change over the past century. Where tomatoes used to be high acid, they are gradually becoming lower and lower acid.
Things that are low acid are dangerous to can without either pressure canning them or giving them a hot water bath. And by dangerous, I mean could kill you.
I don't know about you but if I'm going to die from self inflicted stupidity I'd rather it be something fun like inhaling too much laughing gas or some sort of Bouncy House mishap. Not from eating botulism infused pasta.
You do NOT need to pressure can tomatoes, but you DO need to water bath can them.
So you don't need a pressure canner to can tomatoes. You just need a big pot that will cover your jars with at least 2" of water.
Water bath canning means submerging the jars so they're covered with a couple of inches of water and boiling them for a certain amount of time. You can do this with a water canning pot or even a regular pot if you have one that's big enough.
Pressure canning means using a specialized piece of equipment - the pressure canner. Jars are put inside with a couple of inches of water in the bottom, the lid is locked and the pressure canner builds up pressure and steam inside. This build up changes the atmospheric pressure in the pot and the boiling point of the things inside it, which in turn kills pathogens.
So ... that is your canning lesson for the day. What worked for gramma's heirloom tomatoes (or any other veg/fruit) may not work for today's Frankentomato. The basic canning methods haven't changed, but food has.
Table of Contents
How do you prepare tomatoes for canning?
Regardless of whether you grew your own tomatoes or are buying bushels from your grocery store or market, you have to prepare the tomatoes.
- Tomatoes need to be washed before you put them through the press. If you don't clean them thoroughly any dirt that's on them will end up in the sauce. Not only dirt but bird poop. You can either lay them on a tarp and spray them with the hose or do what I do - wash them in the bathtub.
- Before starting to press go through your tomatoes and cut any in half that are too big to fit through the top funnel. It'll make your life easier later on when you're pressing.
Do you have to cook tomatoes before canning them?
It depends.
- Some people put their tomatoes in a pot of very hot (not boiling) water to heat them up. The heat releases the juices from the tomato and makes them easier to run through the press with more juice being released. This ISN'T necessary but it is a good practice.
- After pressing the tomatoes have to be boiled for 15 minutes prior to their water bath canning.
How to Press Tomatoes.
To Process Tomatoes You Need a Manual or Electric Tomato Press.
A good quality tomato press is around $140. Do not cheap out and buy a plastic one. You'll be cursing the tomatoes, the press and the person who sold it to you within 10 minutes.
Electric presses work much more quickly but are also more expensive.
This is the Electric Tomato Press I own and love. 🇺🇸
But, I got mine years ago and there are highly rated, less expensive models like this now.
This is the manual press I'm using in these photos.
- Just drop the whole tomato into the press, skin and all (tomatoes that are too big to fit in the chute should be cut in half.)
You simply drop the whole tomato into the press and crank the handle. You can fill the entire hopper up and just keep shoving them down the chute one by one.
2. Crank the handle and watch as the juice comes out one end and the discarded seeds and tomato skins out of the other.
The tomato press automatically filters the tomato pulp and juice from the seeds and skin. They come out of the end of the funnel as you can see.
The seeds and skin come out one end, the good stuff out another. Place a large stainless steel pot under the chute to catch the tomato juice. Place another stainless steel pot or bag under the other side of the chute to catch the seeds and pulp. Save them. You're going to put those through the press another 1 or 2 times.
3. Continue until all your tomatoes have been pressed.
4. Now take the seeds and skin you saved in a second pot and put those through the tomato press again. You can press the discards 1-2 times to get as much product out as possible. The final time you run the pulp through it should be almost completely dry.
5. Fill a pot (or two) with your juice, put it on the stove and bring it to a boil. Boil for 15 minutes.
Once these steps are done you're ready to process them.
How to preserve tomatoes in mason jars.
1. Fill your canning pot with water and get it hot.
2. Place clean mason jars (quart sized/4 cups) in a 210 °F oven. (this prevents the jars from breaking when the hot tomatoes are funnelled into them)
3. Line up bowls of brown sugar, salt and citric acid.
4. Cover counter with dishtowels to sop up inevitable spills.
5. Make sure you have a funnel and a ladle. Jar tongs are handy to have too.
This whole event will be much easier if you have the proper tools, a funnel, a magnetic stick for picking up sealers out of boiling water (which you don't need anymore since modern sealers don't need to be heated before use) grabbing tongs for hot jars and a few other things. They aren't expensive, in fact the entire kit of all the tools you need is only about $10, but they're indispensable.
- Once your tomatoes have come to a boil for 15 minutes, you can start jarring your sauce.
- Add 1 teaspoon brown sugar, ½ teaspoon citric acid and ½ teaspoon salt per quart jar.
- Put a funnel over your jar and ladle in hot tomato sauce to ½" headspace* from the top of the jar.
- Wipe the rim of your mason jar with a wet paper towel or cloth to remove any drips that will interfere with the seal.
- Place the sealer on top and then the ring. Finger tighten only.
- Using tongs place the jar into the pot of hot water.
- Continue until the pot is full and then bring to a boil. Boil for 45 minutes.
*head space is VERY important. Too little headspace and your sauce will be sucked out of the jar and sealer while processing. Too much headspace and you might not get a proper seal.
Work with one jar at a time. Don't try to do multiple jars.
Do yourself a BIG favour and cover your work surface with a few tea towels. It's gonna get messy.
How many tomatoes do you need for canning?
1 bushel will get you 20-22 quarts of tomato juice.
2 bushels of tomatoes will get you 42-44 quarts.
Like so ...
These tomatoes will last me 2 years. Now you're probably wondering ... what the hell are you supposed to do with them? They are the perfect base for anything tomato related. Just add spices and a little bit of tomato paste and you have a basic tomato sauce.
Cook it for only an hour and it'll taste very fresh and bright. Cook it longer and it takes on a richer, smokier taste.
Use them wherever you would use canned tomatoes or tomato sauce. Like in chili (I happen to think my chili recipe is one of the best) or for a spicy tomato sauce or ... best of all ... for this ... Gramma's Spaghetti & Meatballs. I also use this as the base of my homemade pizza sauce.
Ingredients
- 1 bushel Plum Tomatoes
- ½ cup Brown Sugar 1 tsp. per quart jar
- ¼ cup Coarse Salt ½ tsp. per quart jar
- ¼ cup Citric Acid ½ tsp. per quart jar
Instructions
- Fill a large pot with water and bring to a boil. This is your hot water bath and should be large enough to fit several jars of tomatoes.
- Preheat oven to 210 and place glass mason jars in oven to heat them so they don't crack when they're filled with the hot tomatoes.
- When ready to start canning, pull a hot jar out of the oven with tongs.
- Put 1 tsp. brown sugar, ½ tsp. coarse salt, ½ teaspoon citric acid into jar.
- Place a funnel over your 1 quart jar and ladle in hot tomatoe sauce to within ½ ” from the top of the jar. The "head space" is very important to get a proper seal.
- Remove funnel and wipe around the rim of the jar with a clean dishcloth or damp paper towel.
- Take sealer ring from hot water and place on jar.
- Screw screwband on. Barely finger tighten only. Do NOT overtighten.
- Once you’ve filled enough jars to fill your canning pot, place your jars inside the pot of water using your jar tongs. Your water should be hot … almost boiling when you place the jars inside. You can also place the jars in the pot one by one as you fill them.
- The water needs to cover your jars by a couple of inches.
- Put the lid on your canning pot and bring the canning water back up to the boil. Once at boiling again you can start your timer.
- Your jars need to boil for 45 minutes.
- Allow the jars to cool slightly in the water bath and then remove them to the counter where they should stay undisturbed for several hours. You will hear the seals "pop" as the pressure changes indicated you have a seal. Any unsealed jars need to be reprocessed or kept in the refrigerator to be used first.
Notes
Nutrition
Tips for Canning
-
- Get everything washed, organized, laid out and ready to go the night before.
- If you don't have a canning pot, just use a large pot and place a metal trivet on the bottom. (the water needs to circulate around and under each jar)
- If your tomatoes are muddy and dirty wash them in the bathtub. If a few only have a bit of surface dirt, just wipe them with a dishtowel.
- Some people also add in a basil leaf to infuse basil flavour into the sauce. I do not.
- Play opera while you're spending the day pressing tomatoes. Even if you don't like opera.
I've done this so many times it's second nature so if you're unsure or think I've left something out let me know.
Now get out there, buy a bushel of tomatoes and give it a shot.
→Follow me on Instagram where I often make a fool of myself←
Cricket
You are a lifesaver! This winter I bought a Squeezo II at the thrift store for $8. I was so excited because I figured it must be better than hand squeezing stuff like my mom did. She had a cone shaped strainer and a wooden pestle. But it didn't come with instructions or recipes or anything. I planted about 80 bazillion tomato plants which are just not coming ripe (just in time for the first frost here in Maine). Now I know how to use it. Hooray! If I just want to freeze the sauce, would I just put int in clean jars, seal and freeze? I am terrified of killing my family. I tried canning jam this summer and it went so badly I had to freeze it all anyway.
Karen
Cricket - Yes, you can freeze the sauce but you should still boil it first. ~ karen!
Jen
ok...now i'm freaked out. my mom and i made salsa and tomato sauce this weekend. we did not boil our jars but we did boil the sauce and salsa. are we going to die???
Karen
Jen - Um ... well I wouldn't recommend doing what you did. Have you done this before, or is this your first try at canning? Almost everything that gets canned needs to be processed in one way or another and you definitely need to heat your jars. If I were you, I'd keep the jars in the fridge and start planning your meals for the next 2 weeks out of salsa and tomatoes.
~ karen
Jen
I meant we didn't boil our jars after we filled them. We ran the jars through the dishwasher then filled them with hot tomato stuff then put the freshly boiled lids on. The ones that 'popped' we put in the pantry. The 'unpopped' jars we put in the fridge. Do you think we'll survive?
Karen
Jen - Did you add lemon juice or citric acid? ~ karen
Jen
We added vinegar to the salsa. We used a prepackaged spaghetti sauce and just followed the directions. My husband is scoffing at me about botulism. Sassy pants.
Karen
Jen - Was the packaged spaghetti sauce *meant* for canning? And poke your husband for me. This is serious stuff. Botulism has no taste, smell or other warning signs and it DOES kill people. If the spaghetti sauce was prepackaged specifically for jarring yourself I'm sure you'll be fine. If it wasn't made specifically for canning, and therefore didn't have a proper pH level I would not use it, I'm afraid. I'm not being overly cautious ... the fact that some of your jars didn't seal is proof that things weren't done quite properly. Personally, I wouldn't risk it. I'd use the sauce you have in the fridge and give the other jars away to people to put in their fridge. They'll last for the next couple of weeks in the fridge but not beyond that. ~ karen!
Eva
that's a crazy amount of tomatoes.... i still have a half a dozen jars from last year so I won't be doing it this year but next year, when I grow more of my own.....
Nancy
I canned quite a bit in my younger days Karen..I know how much work you put into this...The finished jars on your counter look so beautiful..It kind of makes me want to do this again...I must go lie down until this feeling passes...
Stéphanie
Aaaaaaaannnnnnnnd tomorrow, are you gonna teach us how to clean pressed tomatoe juice off of flagstones? ^^
Karen
Staphanie - Well aren't you a funny one. ;) ~karen
Nancy
HAHAHAHA!!! LOVE IT STEPHANIE..
Evalyn
My sister and I spent Sunday processing 120 lbs of tomatoes into juice. I'm getting me a tomato press!
I don't recommend supermarket tomatos, however. Famers Market or U-Pick is the way to go. We paid 50 cents/pound for U-Pick.
Karen
Evalyn - A lot of supermarkets bring in bushels for "doing tomatoes". Mine were $15 per bushel and they were fresh, local tomatoes. Depends on the supermarket I guess. ~ karen!
Shauna
I am so excited you did this post. I just asked for canning equipment and the blue book for my birthday. I have pretty much read it cover to cover and am now completely freaked out and excited to can something. Of course, now I have to wait to buy this tomato press so I can follow your instructions. All the blue book recipes talk about scraping the sides of the jar with a plastic utensil after the tomatoes (or whatever) are placed in the jars. Does this need to be done with your recipe as well? And, yes, I want to know the answer to the question someone else asked about adding other items like onions, etc. I assume (since reading my blue book) that it would then have to be pressure canned or just frozen?
Great post. I hope you do more. I am thoroughly impressed that you were able to do this and take pictures. I'm freaked out about getting this all organized in such a way that things stay hot, etc. and I don't KILL anyone. No pressure. Ha!
Karen
Shauna - Inserting a wooden spoon or rubber spatula is to get the air bubbles out that might be trapped. It's necessary when you're canning something thicker than a pure liquid because anything thicker or something that has chunks (like whole tomato pieces) can trap air and make bubbles. That isn't the case with this straight liquid sauce. So no need really to release air bubbles. They release themselves. And yes, whenever you can you have to use the regulations (canning/pressure cooking times) specific to all the ingredients. So if one item in the recipe only requires 20 minutes of a hot water bath, but another ingredient requires 20 minutes of pressure canning to make it safe, you have to do the 20 minutes of pressure canning. Understand? It's hard for me to describe for some reason! ~ karen
Shauna
I do. thank you. I thought about the releasing bubbles thing after I wrote it and realized that it was a silly question, but thank you for answering anyway:)
Are you able to create your own recipes now based on what you know from books, or do you still have to use recipes from books? When I started all this, I had this vision in my head that I would be able to make my 'famous tomato sauce' and be able to can it, but am realizing that if I don't follow a recipe exactly, I could kill someone. Is there anything anywhere that helps you be able to can your own recipes?
Linda
I've been doing this my whole life. My parents are freaks and do 15-20 bushels. We wake up at 5 am. I dreaded it when I was younger and thought of every excuse imaginable why I needed more sleep. However now I do appreciate it. We sit there, wash and cut every single tomato to make sure there is nothing rotten. By the end of that process my hands are prunes and I will have at least 1 finger that needs a tiny bandaid (I cut them like an Italian nonna with the knife towards my finger. Bad habit but I can't shake it.) Anyway the dinner at the end of the day is always the best with the fresh sauce.
We never use brown sugar, but I am intrigued and really want to try it.
We always just put fresh basil in from the garden and some salt.
This year we also changed our process and no longer boil the jars. We'll see what happens :)
Uturn
Question....is it ok to saute things like onion, pepper, celery to cook down with the tomatoes prior to canning for extra flavor/texture in the sauces? Does that change the pH?
Karen
Uturn - If you were to add onions or celery, you'd need to process the jars to whatever time those ingredients require. When you can you need look at all your ingredients and then process to the vegetable/fruit that requires the longest processing time. That's why if you're making sauce, you're best to just make the base and then add your onions, carrots, spices, garlic etc. after. ~ karen!
ashley english
fabulous post, per usual karen. kudos to you and your canning self! i'm wondering if you'd be willing to share the brand of the tomato press that you're using. i'd love to find a similar one for my own tomato escapades. thanks!
Karen
Hi Ashley - I use the Tre Spade Tomato Squeezer Number 3. Good, solid press. If I can find some I'm going to do the peaches from your cookbook next! ( http://tinyurl.com/3sec9vq )
cred
I gotta get me a tomato press- wow! I've heard of this either.
Another tip, although widely used in canning tomato recipes, is using bottled lemon juice to bring the acidity up. 1 tbsp per 500mL jar Or you can use vinegar- 2 tbsp per 500 mL.
Not just the new-fangled tomatoes are low acid- many heirloom varieties are low acid. And the colour or the taste of the tomato is no indication of acidity. Yellow tomatoes, introduced to the mass market as low acid are not all low acid and not all reds are high acid. Those that taste sweet may have high acid but the higher sugar content masks the acidic taste & vice versa.
So, blah, blah, blah... you just don't know what you're getting so add lemon juice, vinegar or citric acid to play it safe.
Babie Knoop
I have been canning for years and did not know about the press either....I just canned the whole tomato in a water bath too.
I do have a pressure canner but I kinda hate it! Did beets in it this year. I am going to try your press and method this year for my tomatoes....getting ready to do them maybe tomorrow. Still have tomatoes out on the vine....(if they didn't freeze last night)!!!
Tracy
Wow; I've got to go find me a tomato press!! Didn't know such a thing existed. One tip I think is a 'good to know' -- don't use an aluminum pot or spoon. Something about the tomato reacts with the metal and you can get a funky taste. I dont know if that taste is obvious to everyone or just critical foodies, though, so maybe its not a biggie. Oh, and because of the lack of acid in tomatoes, I've also added some lemon juice; just enough to boost that acid level up a bit.
Tracy
Wait - I just saw 'citric acid' in your recipe. Duh. That's what that's for! Forget the lemon juice!
Elgog Partynipple
I use only stainless steel pots and pans. Aluminum and copper reacts with acids and create a metalic taste in things. It also discoloers the cookware. When I was a chef (for many years) we used only aluminum cookware. I don't really know why that is. Also, the knives we used were the cheapest knives known to man. They would chip or shatter. When they broke, you threw them away and pulled out a new one. No sharpening. Watch cooking shows that show chefs working in commercial kitchens. They all use that white handled knife. That's the cheap knife all kitchens use. It's the same with all the beatup cookware. It's all aluminum.
Karen
Hi Tracy - You're right .... no reactive pots or utensils. ~ karen!
Langela
I agree with needing the tomato press. I also have extra striners for berries, grapes, squash, etc. It is great for applesauce! I love the look of freshly canned jars of stuff lined up on the counter. They are so pretty and the feeling of accomplishment is amazing. BTW Karen, I really like your square jars.
Karen
Thanks Langela! I like the squarish jars too. :) ~ k
Jessica
my m9m makes fun of me for my love of square jars. We canned the old way because of using heirloom varieties in our sauce plus lemon juice, but for sauce nothing, I do get botulism paranoia though. . . .
Jessica
and by sauce in the second instance i meant juice
Mandy Y
Can you use a mouli instead of a tomato press? Seems like it would do the same job :)
Karen
Mandy - It can be done, but if you're doing 2 bushels ... or even 1 bushel of tomatoes I wouldn't recommend it. It would be too time consuming. With the press the skins and seeds are automatically dispensed out one side so you can keep cranking and pressing for a long time. A food mill you'd have to empty the top out after every several tomatoes. Plus, with a press you extract every single bit of juice/pulp. More than you would with a mill. If you plan on doing this, an actual press is worth the investment! ~ k
Brenda K-C
I use a food mill rather than a press for the tomatoes because I really liker them chunkier than the press allows.But I agree with you that the tools must be well made to avoid frustration.
Lui
Opera adds the italian touch, isn't it?
I love your blog!
Karen
Thanks Lui. ~ karen
Trysha
Canning totally intimidates me. I'm afraid even if I do it right, we're all gonna die of botulism. Or I will really excel at it and we'll be eating jarred pumpkin butter/vanilla pear jam until the End of Days.
I go from one extreme to the other. I'm hard to live with.
Kitt
Wow. I've never seen (or heard of!) a tomato press before. Now, of course, I want one in the worst way. I've peeled and seeded my entire tomato crop by hand, and then roasted and pureed them to make sauce. Which I froze.
OK, bookmarking this post for next year. I swear.
Brava on your productive day! You will enjoy the fruits of your labors, indeed.
Karen
Kitt - That's exactly the reason I did this post. An astonishing amount of people don't know about the tomato press. When I was looking up how long I needed to water bath my tomatoes I didn't find a single recipe that talked about using a tomato press. So, I figured I'd better do a post on it. Even though it's already a huge, messy, annoying, exhausting job as it is - let alone having to do it and photograph it at the same time! ~ k
Uturn
I do have a tomato press and used it once before reading this blog sent to me by a friend. I HATED it!!! It seemed like an acrobatic feat to get the sauce to go into the container. I had to use a cake pan to catch it because that's all that fit underneath it. Seemed like the same amount of effort to do it this way as to boil them shortly and peel then throw in the blender. Also, all that goop coming out of the end of the press was a nightmare to control. I did try the bag like in the picture, but it did not work so well. I ended up using a cup which I had to dump frequently. I was also not happy when the crank wiggled the clamp off the table and the whole works came tumbling down. Yes, this is a good quality metal press from Fleet Farm.
The worst part about the ordeal was the cleanup! That strainer didn't come clean despite scrubbing and soaking. I ran it thru the dishwasher and now there appears to be some rust on it.
This is only my first year of both gardening and canning, so I'm learning lots and was never shown by other generations so I have a lot to overcome. This was just one experience of many
Karen
Uturn - If you have a good ($100 - $150) all metal press it sounds like you just don't have it set up properly. Take a look at how mine is set up. You have to attach the press to something it can clamp onto firmly like a square edge table or 2x4. The spout of your press should hang over the edge of the table so you can put a huge pot underneath it. Depending on the size of your pot, you may need to raise it up a bit on bricks so you don't get a lot of splashing. If you set it up like this, wrapping a full sized garbage bag around the chute the pulp and seeds comes out of should work perfectly. The bag will be long enough to rest on the floor and will collect the seeds and pulp from bushels and bushels of tomatoes. Lemme know if you have any other questions! ~ karen
Buvezdevin
If you have a KitchenAid mixer, getting a couple of attachments will make it a powerful motorized tomato press.
You need the "food grinder" and the "fruit & vegetable strainer" and while you don't have to have the "food tray" it will hold a lot of fruit/veg for feeding into the grinder.
Also, putting the skin/seeds through any tomato press for a second pressing will extract even more juice and pulp, less quantity but thicker than first pressing.
Karen
Buvezdevin - I *do* have a KitchenAid and I also have a food grinder for it. Not the fruit and veg strainer though. Might look into it. I have put the skin and seeds through for a second pass, but I find for the amount of juice I get from it and how long it already takes to do 2 bushels of tomatoes, I'm fine to just feed them to the chickens, LOL. At the end of bushel 2, I'm DONE. :) ~ karen
Buvezdevin
Oh, Karen, I meant a generic "you" for your fans who may be looking to buy a tomato press. If I had the press in your photos, I might not have bought the KitchenAid attachments. That said, I lurv them and put up my first tomatoes this year.
I am bookmarking this page for tips and reminders for next time canning.
Now, that we know you have ample homemade tomato purée, I am soooo looking forward to any further recipes using such, and will definitely be trying Gramma's recipe you suggested above.
Marti
Ok, so I stumbled on a brand-new blue graniteware pot with a metal "steamer pot" in the bottom.
I don't think I can get this interested in tomatoes this year (bought a butt...er boat-load at Costco a while back that I still haven't used), but other than that, am I good-to-go on canning stuff with that pot, K?
Karen
Marti - Mmmm. I don't know. Hard to tell w/out seeing it, but as long as the jars don't touch the bottom and the pot is tall enough to get 2 " of water over the top of the jars you should be fine. ~ karen!
Marti
I think I'd be canning short jars.. relish/small bits of picklednessiticity only. Bummer. Next year!