Saving Tomato Seeds & Kicking Sauce

saving tomato seed

The late summer harvest from the garden is starting to pile into the kitchen and now is a great time to save some seeds from the pick of your tomato crop.  This season I grew a load of new varieties that folks have given me over the past couple of seasons, varieties that all came highly recommended and got duly tucked away in my seed tin to grow “one day”.

It turns out that they came highly recommended for good reason.  Now I am at the harvest end of the season I can see exactly why those who gifted me the seeds were so impressed by these tomatoes. Each has something different to offer and I will be saving the seeds, growing them again and sharing them with fellow gardeners.

This year’s tomato hall of fame includes:

  • Pauls Crinkly – a whopping big meaty tomato from Paul and it is crinkly.
  • Romano’s Capri – an Italian heirloom called Capri that has been grown by the Romano family in Nelson since the 1920’s. Superb flavour and very fleshy.
  • Bobs Low Acid Beauty – from Bob who makes the cider presses – very similar to and may well be Capri but bigger.
  • Oak Canning Factory – from a chap who’s name I sadly can’t remember – his Dad used to grow these in Papakura in the 60s for the Oak Canning Factory – a fascinating bush tomato that grows on the ground like a nest and is chokka with round red toms – very disease resistant and compact
  • Bruce Leopold’s Jersey Island – from Bruce who said it was prolific and he was right – smaller tomatoes in perfect trusses of up to 16 fruit from tip to toe of the plant.

Capri Tomato

I’ve learnt the hard way that when someone gives you some seed, get all the info you can about it then and there. It is often the only time you will have with this person and a valuable chance to find out the story behind the treasure they’re giving you.  Write it down so you can pass it on with the seed when you share it.

Oak Canning Factory Tomato

Tomato seeds are easy to save. Make sure you’re saving seed from an open-pollinated heirloom variety, not a modern hybrid as these won’t grow true from seed. Hybrids are crosses between different varieties and generally have F1 or similar after the name on the seed packet.  Heirlooms are not created by crossing varieties and therefore, they will grow true from saved seed.

Tomato flowers generally don’t cross-pollinate with other varieties so it usually doesn’t matter if you’re growing a lot of different varieties close together. If you want to be extra careful you don’t get a natural hybrid (ie. a bee cross-pollinating between two different varieties) put a piece of cotton muslin loosely over a bunch of unopened flowers and secure it with a rubber band. When the flowers open, give them a bit of a shake to move the pollen around each day inside the cloth and then wait to see you have fruit forming. This will guarantee pure seeds to save.

Jersey Island Tomatoes

To save the tomato seeds squeeze them out onto a saucer, separate most of the pulp and scrape the seeds into a jar with 1/2 a cup of water in it. Sit the jar somewhere warm out of the sun for a few days until a film starts to form on the top.  This film shows the seeds have started to ferment. Fermenting your seeds isn’t essential but it gets rid of the gel coating on the seed which can stop germination. These fermented seeds are cleaner, store better and grow better so it is worth a little faffing around.

Pour the water off carefully and add fresh water. Swish it around and pour it off again. The good seeds will sink and any you pour off any bad seeds and pulp. Keep doing this until you have clean seeds then dry them carefully on paper towels and when they’re completely dry store them in sealed containers in the fridge. Don’t forget to label the seeds during the different stages of saving them so you know who is who.  Tony Romano who gave me the Capri seeds said he stores his seed in the fridge and has been able to germinate seeds that are over 20 years old.

chilli tomato sauce

Making the tomato sauce is a bit of an annual ritual in my kitchen. The ingredients list is long and so is the cooking time so you kind of make a day of it.  Once a year in late summer when I’ve had enough tomatoes on toast, I start collecting up the tomatoes for this sauce that will last all year. This isn’t fancy passata tomato sauce for all those lovely Italian pizza, pasta, polenta dishes. This is old school, dip your sav in, tomato sauce.  So old school I won’t even call it ketchup. This recipe has evolved over a few years into its current form and is universally loved by everyone who tries it – everyone who loves food with a bit of a kick that is – it is a bit fiery.  If you’re making it for kids or prefer a milder version, leave out or halve, the chili, mace, ginger, smoked paprika, garlic, mustard and black pepper.


  • 6kg of really ripe tomatoes
  • 4 red peppers de-seeded and roughly chopped
  • 6 medium white onions roughly chopped
  • 3 cups wine vinegar (red or white)
  • 2 cups raw sugar
  • 3 tablespoons non-iodised salt
  • 3 fresh red chilies or 1 tablespoon dried chili flakes
  • 1 whole bulb of garlic peeled and chopped
  • 3 bay leaves
  • 1 tablespoon freshly ground black pepper
  • 1 1/2 tablespoons ground mustard powder
  • 1 tablespoon ground allspice
  • 1 1/2 teaspoons celery seeds
  • 1 1/2 teaspoons smoked paprika
  • 1/2 teaspoon mace
  • 1/2 teaspoon ground cloves
  • 1 teaspoon ground nutmeg
  • 1 teaspoon ground cinnamon
  • 1 teaspoon ground ginger
  • zest of one lemon

tomato chilli sauce


  • Prepare your bottles. I save up glass bottles with nice wide lids for my sauce. Only save bottles with metal or cork lids. Plastic lids tend to melt when you sterilize them with boiling water.  You’ll want around 5-6 liters worth of bottles ready – if you like a thicker sauce you’ll only need around 4 liters worth of bottles.  Just add up the mls of each bottle on the calculator as you clean them. Clean the bottles in warm soapy water, rinse in clean water, drain and put them in a meat dish ready to go into the oven to be sterilized.  Wash the lids in the same way and put them in a pot of water to be boiled.
  • Wash and roughly chop the tomatoes, removing the green hard bits at the stalk, and put them in a large (8-10ltr) heavy bottomed stainless steel pot
  • In a food processor whiz together the garlic, chilies, onions and red peppers until they form a chunky salsa (that’s a consistency, not a dance)
  • Grind the spices if you’re using whole spices.
  • Add the red pepper mixture and all other ingredients to the tomatoes and cook it over a low heat until the tomatoes break down, stirring often with a heavy wooden spoon so it doesn’t stick on the bottom.
  • After 3 hours of gentle simmering and occasional stirring, run the whole mixture through a mouli using the middle sized plate – you don’t want it too smooth.  If you don’t have a mouli you can put a sieve over a pot and push the sauce through with the wooden spoon but do think about getting a mouli – they make short work of jobs like this and you can usually pick one up in a second-hand store.
  • You can turn the oven on now to 70°C to sterilize your bottles and put the lids in a pot of water to boil on the stove. Turn it off once it has boiled.
  • Return the sauce to the pot, increase the heat and stir it more often until it is as thick as you want it.  This is when it can burn so do perch next to the pot.   To test if it is thick enough, put a spoonful on a clean plate and push your finger through it. If it leaves a line it is getting thick enough, if lots of liquid still runs around the plate it has a way to go.  As a rule, I’ve found reducing the strained sauce by a further third is about right – or a further 2 hours cooking time.  Be patient – no-one likes a runny sauce. The sauce also changes to a deeper red as it thickens.  If you bottle it when it is too thin it is not the end of the world – you can redo it – you just need to wash the bottles again.
  • When you’re happy with the thickness, get the lids on the boil again, remove sauce from the heat, take the bottles out of the oven, drain the water from the lids and without mucking around fill the bottles through a funnel to within 2cm of the top. Screw the lids on each bottle as  you go – wipe the necks with a kitchen towel before you put the lids on if they have sauce on them.   Doing this quickly while bottles, sauce and lids are all still hot is important – use some oven gloves or cloths so you don’t burn yourself on the bottles.
  • Sit the bottles on a wooden chopping board to cool, they can crack if you bang them down on a ceramic benchtop – label them then store in a cool, dark pantry for use throughout the year.  The sugar and vinegar are preservatives so you don’t need to keep it in the fridge.

heirloom tomato seeds




  1. Thanks so much for the info on how to save the seeds! Next season, maybe a tutorial on how to stake, for those of us who are completely useless on that score?

    1. yes please, this year mine seriously outpaced the pathetic provisions i’d made, and i’d also like to know whats so wrong about leaving on some laterals?

      1. Hi Heather, see my reply to Karen on the staking methods I use. Nothing wrong with leaving laterals on your bush and cherry toms – the more the merrier. If you leave laterals on your indeterminate varieties you’ll get lots of small fruit that doesn’t ripen as well as the plant gets clogged up – also the laterals won’t support the weight of the big fruit these types produce and they will snap.

    2. Staking is a dark art for tomatoes – everyone invariably under-stakes and when the tomatoes get a good load of fruit on the stake wobbles over – or the stake is too short and the tomato keeps on growing. Determinate tomatoes (bushy types and most cherry types) I use a cage of circular metal rings as a support – or let them ramble along the ground. Indeterminate tomatoes (generally the bigger fruited toms) I use a single 2m hazel wood stake and tie the tomato to it with rubber ties or cut up old tights or socks. I nip the top out of these ones around late Jan or the fruit that sets doesn’t get a chance to ripen and it helps put all remaining energy into ripening the lower fruit.

  2. Hi Heather,
    You can sterilise plastic lids with sodium percarbonate which you can buy as ” No Rinse Steriliser” for home brewing. This is an eco-friendly product.

    1. Oh that is good to know Eve – thanks for that – it extends the options for jars doesn’t it.

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