tomato starter jars

Tomato Starter Jars: How to Make a Mix That will Bring Your Savoury Cooking to The Next Level!

Share Post:

tomato starter jars

I’m not sure how many of you know this but writing blog posts can be stressful!!

I mean, some days I’m just plugging away in the kitchen and I think, “Oh I should post this…people would love this recipe!”.

So I make sure the recipe is developed properly and all the measurements and instructions are correct…then I remake the recipe and photograph it…then I edit the recipe as well as all the photographs…then I input it into the blog and publish it.

But most blog posts aren’t that easy.

Take this tomato starter jar recipe…

I was taught how to make these by my mom’s friend a few years ago and thought it was a great idea!! I started canning this mixture during “tomato canning season” and the jars sit alongside my tomato passata in my cellar where I “oooo and ahhhh” whenever I walk in there to grab something (preserves are sooo pretty, don’t ya think??).

But this recipe was different than other preserves I’ve made. It was a sort of “made up” mixture (I changed the ratio of the ingredients from the original recipe and added a few more things) that I put into jars according to flavors I think would elevate an Italian dish. And even though I’ve been doing this for a few years, I changed the instructions for this recipe at the last minute and the reason it changed was because I love you guys to death – or, actually, I love you to life.

Let me explain…

This year, when I was at an event that was all about canning tomato passata, my friend Ema (who teaches canning and preserves at George Brown College) told me a little something I knew nothing about.

She said I have to be careful because the acidity level when canning has to be “just right” or the tomatoes will go off (I believe the ph meter has to read 4.6 or below). And apparently, even the tomato puree that we’ve been making for years may need a bit of help (tomatoes here in Canada have become less acid over the years and Ema suggest adding a pinch of citric acid to each jar just as an assurance).

So why am I telling you this?

Because, even though I’ve been canning for years, without a proper ph gauge, it’s hard to tell if a mixture is perfect to bottle and put through a water bath. Passata is generally fine (although I may now add a pinch of citric acid to each jar now) but this mixture is made up of a few different ingredients and if the ratios change, your acidity is thrown off. Ema suggested I go by the ratios that are shown in this post by the Center for Home Food Preservation for salsa but this isn’t really salsa so it was hard for me to change the ratios. If you’re interested in learning more about the safety of canning, here is another article that you might find interesting!

So to be honest, I just don’t want to take a chance (even though it’s been fine for years over here!) and have anyone die on me because you ate tomatoes!  So, let’s keep things safe…I’ve given you the recipe below and you have two options for storing it.

So, let’s start with finely chopped tomatoes…you want them to be ripe but still somewhat firm. And, if the seeds bother you, you can remove them (I’m too lazy!)

tomato starter jars

Next, I add a can of San Marzano tomatoes from Italy for two reasons: First, they add a bit of thickness because of the puree that they are canned it and second, they balance the acidity a bit better (I was told that Italian tomatoes have a different balance of acid because of the soil they’re grown in!)

tomato starter jars

Next, add your chopped onions…

tomato starter jars

And your parsley and basil…

tomato starter jars

As well as your celery leaves (I feel like this flavour is a game changer!)

tomato starter jars

If you want to try and bottle it, adding a pinch of citric acid will balance your ph a bit better (this stuff is also great on homemade guacamole!!!)

tomato starter jars

This is toum…a Lebanese garlic paste that my friend Cosette makes and I am obsessed with! If you want to try your hand at it, check out her recipe here! You can also sub in minced garlic cloves if you like!!

tomato starter jars

And here they are in all their beauty!

tomato starter jars

So, once the mixture is made, you can either scoop it into freezer bags (in about 1 cup measures – remember, this is just a flavour enhancer so you don’t need a lot!) or you can keep them in the canning jars with about 3/4″ head space to make sure you have room for expansion as it freezes (yes you can freeze canning jars!).

Your other option is to cook the entire mixture down and freeze it cooked (it will act more like this veggie boost sauce I made a few years back:

roasted veggie booster sauce

Either way, it’s a great little thing to have tucked away in your freezer for those days you just need to up your flavor game!

I can’t wait to see what you guys do with this!!!!!!

tomato starter jars

tomato starter jars

Tomato Starter Jars

If you need a flavour booster to start a sauce (or even a slow cooking roast), this mixture is your new best friend!!


  • 8 large vine-ripened tomatoes
  • 1 796 mL can good quality Italian tomatoes, crushed with you hands
  • 6 small yellow onions, chopped (about 3 cups)
  • 6 cloves garlic, minced (or 2 tbsp toum)
  • 1/2 cup basil leaves, torn
  • 1/2 cup parsley leaves, chopped
  • 1 cup celery leaves, chopped
  • 3 tsp salt


  • In a large bowl, mix together all ingredients until well combined.
  • Place mixture into 500 ml canning jars with about 3/4" headspace to leave room for expansion in the freezer or in small freezer bags in 1 cup measures (make sure to remove all the air before sealing)
  • Freeze for up to 1 year.