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How to make the best cumquat jam

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How to make perfect cumquat jam with step-by-step photos. Follow these tips and tricks to make the perfect homemade cumquat jam. Great to have at home or for gifts.

I have a love-hate relationship with cumquats (or kumquats as they are known in the US). The tasty result is really the only thing that allows me to overcome the fact that I hate chopping them up. Our tree produces an over-abundance of fruit every year, so I have become very skilled at finding new ways of cooking with cumquats. Cumquat jam is also not a common jam, so it’s great to be able to make something that can’t be found everywhere. It also makes the perfect gift.

But, I also have a ‘love’ relationship with jam. I blame France for that. I love the sticky pots of fresh fruit that I smother on a baguette, or eat in a beautiful pastry. Back home, I love trying to replicate these wonderful jams.  There is nothing like making your own jams and now, I find myself wanting to make more and more things with our citrus fruit.

This old-fashioned cumquat jam recipe is a family one that has been handed down over generations.

Being such a small fruit makes it tricky to prep them. But, like anything in life, if you put in the hard yards upfront, you will be ultimately rewarded. It’s important to start with fresh cumquats. Having them fresh makes them easier to cut.

I’m lucky because I have a tree so I can harvest them whenever they are in season. 500g (1.1 lb) of fruit is enough to make a couple of bottles of cumquat jam. Because it isn’t the quickest thing to prepare you probably don’t want to use any more than that at one time.

Why this recipe works

This cumquat jam recipe works because of the attention to detail that is given in the preparation stages. Whilst it is labour intensive in the first instance, sticking at it will ensure you have great jam at the end, and your effort will be rewarded. There are other recipes on the internet for “easy cumquat jam”. They might be easier, but they don’t always set and it doesn’t taste exactly the same. The texture is different and quite often it’s full of seeds. This is a seedless cumquat jam.
The cumquat pith and seeds are high in natural pectin meaning that you will get a good set on your job every time.
This recipe does not recommend making it in large batches. So, whilst it will take a while to prepare your fruit, you can manage it with small amounts of the fruit to start with.
The jam, once made, will last quite a while in the fridge, meaning you can take advantage of the fruit when it is in season, and enjoy it all year round.
There is no wastage. All parts of the fruit are used in this jam.
This is a jam with a strong flavour and unlike many commercial jams, is not overtly sweet.
It’s versatile. Cumquat jam can be used as a breakfast item but is also great in cakes and biscuits. Cumquat jam makes for a perfect jam drop!

Tip:  Don’t be tempted to make larger batches of this.  Whilst items such as cakes can easily have their mixture doubled even tripled, jam does not react well to this at all.  The more fruit, the more sugar, the more liquid is produced, the longer the cooking time, the greater the impact on the pectin and so it goes on.  Cooking jam for too long also takes the flavour out of it.  Less is more when it comes to making jam.

Recipe ingredient notes

  • White sugar may be substituted for raw sugar. The measurement remains the same.
  • Whilst this recipe notes 500g of cumquats in the ingredient list, it really does not matter. Once you have processed the fruit and are ready to cook, you will measure the amount of fruit you have and use that as the basis for the amount of sugar. At this stage it does not matter whether you cooked with 300g, 500g, or 800g.
  • No additional pectin is required.
  • The recipe calls for juice of one lemon. Whilst there is no specific measurement for this, I always like to try and use the largest and juiciest lemon I can find.

What is a cumquat?

Cumquats (Kumquats) are a bright orange citrus fruit. Depending on the variety, they can be oblong or spherical. The skin and the fruit is edible and have a distinctively sour taste to them. On first taste, they will have you screwing up your face for sure. Cumquats are extremely versatile, and whilst this recipe is for cumquat jam, or cumquat marmalade as it is also known, we use them for many different things. Icecream, relishes, chutneys, cakes, biscuits and syrups, they are a wonderful addition to many foods.

How to make cumquat jam

Step 1

This is the most important part of the process, but the most time-consuming. It’s the part where you need to cut the fruit and separate the pith and seeds. The setting agent in this recipe comes from the pith and the seeds, making it critical to get as much of it as you can in order to allow the cumquat jam to set.

Because this fruit is small, it’s easiest to first cut the fruit in half, then in quarters. This way you can then cut the centre pith out without digging around in the fruit.

Tip: If you have a pair of sharp kitchen scissors, these will also make the job a little bit easier. You will still need to cut the cumquats into quarters, but then just cut across the top to get the pith out. It’s easy enough to do it in your hands and not have to put it on a cutting board. The end of the scissors can be used to pick the seed out easily.

Step 2

Put pith and seeds into a bowl and put enough water in just to cover them. There is no exact measurement here. As long as you don’t flood the pith and seeds with water, it will be fine. Place plastic wrap over the top of the bowl and leave overnight. Do not put it in the fridge.

making cumquat jam
Covering the pith and seeds with a little water. 

Step 3

Process the remainder of the fruit. Place the remaining fruit into a food processor and puree. This should be quite a thick consistency.

Step 4

Pour the processed fruit into a separate bowl, and also cover with just enough water to coat the fruit. This should also be left overnight on a bench, not in the fridge.

Processing fruit to make cumquat jam

Step 5

This step is all about cooking the jam.

Cook’s tip: Before starting the cooking process, the quantity of fruit needs to be measured, to determine the amount of sugar to be included. Sugar is added on a basis of one cup of sugar to one cup of fruit. To be clear, the fruit is measured after it has been sitting overnight, not the original weight of the fruit in its natural form. Measure out the fruit into cups and make a note of how many cups you have. You will need to match this with the sugar very soon.

procesed cumquats and measuring cup

Put a saucer in the freezer. This will be used to test the jam later.

Place pith and seeds into a saucepan and bring to a boil. Cook for 10 minutes. If there is not much water here (ie you’ve been restrained when covering the pith the day before, it is ok to add a little more here, just so your pith and seeds won’t burn).

cumquat seeds and pith in bottom of saucepan

Strain the liquid into the other bowl of prepared fruit. Use a teaspoon to push the thick liquid through the strainer. You will need all of this as this is what will make your jam set. I move the spoon around and around and push down on the seeds and pith to extract every bit of pectin I can. Add the juice of one lemon to the fruit.

cumquat pith and seeds in a strainer over bowl of processed fruit

Put all of this (not the seeds) into a saucepan. Heat the fruit for five minutes before adding 1 cup of sugar for every cup of fruit. (see cook’s tip above)

Bring to the boil and keep stirring so it doesn’t stick to the saucepan. Rolling boil for 20 minutes.

cumquat jam in saucepan on rolling boil

After 20 minutes put a drop onto the saucer that you placed into the freezer to see if it will set. Run your finger through the jam on the plate. It should be slightly sticky and set, and maybe wrinkle up as your finger passes through. If it does this, it doesn’t require any further cooking. If it’s runny, keep cooking. Cooking time shouldn’t exceed 30 minutes.

testing jam on white plate with spoon

Step 6

Once the jam is ready, allow it to cool slightly before pouring into sterilised bottles (see tips below). Refrigerate.

finished bottles of cumquat jam with fresh cumquats and english muffins

How to sterilise bottles

When preserving food it is especially important to have sterilised the bottles before adding any food to them. Depending on how much time we have, we use one of the following methods.

Sterilising in the oven

Place the bottles – upside down is best – on baking paper inside a baking tray. Place into an oven at 110 degrees Celsius (230 degrees Fahrenheit for 10-15 minutes. The lids can be sterilised this way as well, provided there is no plastic inside them. Remove from the oven and use as soon as possible.

Sterilising on the stove

Place a tea towel on the bottom of a large pot and put the bottles on top. This prevents the bottles from moving around once the water starts to circulate. The lids may be added to the pot as well. Bring the water to a boil and leave for 10 minutes before removing them.

Note: Don’t ever put cold bottles into hot or boiling water as they are likely to crack. Warm them up first.

Recipe FAQs and Expert Tips

Can I substitute another fruit for cumquats?

Technically your could, but the secret of this cumquat jam recipe is that it uses the pith and seeds for pectin. Many other jams do not use the pith (because they may not have enough) and rely solely on lemon juice or manufactured pectin. Another citrus fruit could be tried using this recipe.

Why isn’t there a measurement for the water components?

The water isn’t measured in ml or cups as it isn’t a key ingredient in the whole recipe. You just simply need enough water to cover the pith and seeds, and the fruit. See the photos above to see how much water is necessary.

Do I need to leave the mixture overnight?

If you were to start this recipe at the beginning of the day, you could make it at night. Give it at least 10-12 hours to do its magic.

Setting the jam

The jam will still appear a bit runny whilst it is still hot. It will set into a jam consistency once it cools.

Can I just process the fruit altogether with the seeds and pith?

You can but the result will be different. We’ve tested doing it this way, but you end up with bits of seeds in the jam and you run the risk of the pectin not developing properly.

What type of sugar is used?

In this recipe, standard white sugar is used. We don’t recommend changing the amount of sugar required. White sugar can be substituted with raw sugar.

What size jars do I need?

You can use any jars you like. Generally, we use jars that are around 385g (0.8 lb). 500g of processed fruit usually generates about 2.5 standard jam bottles.

Do I need to refrigerate the jam?

If you have sterilised the jars properly, you should be able to store your jam in the pantry as you would any commercially bought jar of jam. Or, you can refrigerate if you have space.

Tip for cutting the fruit

I set up a production line when I am preparing the fruit. I cut all the fruit that I am planning on using first into quarters and place them into a bowl. Then I put an empty bowl next in line for the pith and seeds and then place the food processor bowl at the end. With my scissors in one hand and the fruit in another, I pick the pieces up one by one, cut the pith and any seeds out of each quarter, put them into the middle bowl and then the remaining piece of fruit into the food processor bowl. Once you’ve done a few like this, you’ll get faster and faster. I can quarter, de-seed and remove the pith of one kilogram (2.2 pounds) of cumquats, and have the fruit processed and all bowls covered with water in under an hour.

fresh cumquats and cut cumquats

How to make old fashioned cumquat jam

Yield: 3 bottles
Prep Time: 2 hours 1 second
Active Time: 1 hour
Total Time: 3 hours 1 second

This old-fashioned cumquat jam recipe is a family one that has been handed down over generations. It takes a bit of time but the end result is a delicious jam.

Ingredients

  • Fresh cumquats (about 500g or 1.1 lb)
  • 1 cup sugar per cup of fruit
  • Juice of one lemon
  • Water

Instructions

  1. Cut cumquats into quarters and cut the pith out and remove the seeds.
  2. Put pith and seeds into a bowl and cover with just enough water, cover with plastic wrap and leave overnight. Do not put it in the fridge.
  3. Place the remaining fruit into a food processor and puree. This should be quite a thick consistency.
  4. Pour the processed fruit into a separate bowl, and also cover with just enough water to coat the fruit. This should also be left overnight on a bench, not in the fridge.
  5. The next day, the jam can be cooked. Note: Before starting the cooking process, the quantity of fruit needs to be measured, to determine the amount of sugar to be included. Sugar is added on a basis of one cup of sugar to one cup of fruit. To be clear, the fruit is measured after it has been sitting overnight, not the original weight of the fruit in its natural form. Measure out the fruit into cups and make a note of how many cups you have. You will need to match this with the sugar very soon.
  6. Put a saucer in the freezer. This will be used to test the jam later.
  7. Place pith and seeds into a saucepan and bring to the boil. Cook for 10 minutes. Strain the liquid into the prepared fruit.
  8. Add the juice of one lemon to the fruit.
  9. Put the fruit (which now includes the juice from the pith, seeds and lemon) into a saucepan. Heat the fruit for five minutes before adding 1 cup of sugar for every cup of fruit. (see Cook's tip above)
  10. Bring to the boil and keep stirring so it doesn’t stick to the saucepan. Boil for about 20 to 30 minutes. After 20 minutes put a drop onto the cold saucer and see if it will set. If not, keep cooking and repeat the process. Cooking time shouldn't exceed 30 minutes.
  11. Once the jam is ready, allow to cool slightly before pouring into sterilised bottles.

Notes

  • It's important to start with fresh cumquats. Having them fresh makes them easier to cut.
  • The setting agent in this recipe comes from the pith and the seeds. Because this fruit is small, it's easiest to first cut the fruit in half, then in quarters. This way you can then cut the centre pith out without digging around in the fruit.
  • It might seem easier to throw all the seeds in, but take the time to remove them now and it will save time in the end, and give a better end result.
  • It's easy to learn how to make cumquat jam and this is an easy cumquat jam recipe.  Just don't let the annoying cutting process stop you from doing it. It makes such beautiful jam that everyone who loves to cook should make it at least once.
  • Cook's tip: Before starting the cooking process, the quantity of fruit needs to be measured, to determine the amount of sugar to be included. Sugar is added on a basis of one cup of sugar to one cup of fruit. To be clear, the fruit is measured after it has been sitting overnight, not the original weight of the fruit in its natural form.

Nutrition Information:
Yield: 48 Serving Size: 25g
Amount Per Serving: Calories: 18Total Fat: 0gSaturated Fat: 0gTrans Fat: 0gUnsaturated Fat: 0gCholesterol: 0mgSodium: 0mgCarbohydrates: 5gFiber: 0gSugar: 5gProtein: 0g

This data was provided and calculated by Nutritionix.

Did you make this recipe?

We'd love for you to share it and show us how you went. Mention @beerandcroissants or tag #beerandcroissants

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fresh cumquats and cumquat jam

41 thoughts on “How to make the best cumquat jam”

  1. This looks so good! I have never seen kumquats like that before-the ones I see in my supermarkets are more oval shaped. I will have to try this when they are in season here!

  2. I got some cumquats from my aunt and just made the jam following your recipe. The result is amazing! Thank you very much.

  3. My cumquat tree is loaded and I have now made 3 batches of jam using your recipe – absolutely delicious. Thank you for sharing your recipe. ? Jill

  4. Hi Jill, they really produce a lot of fruit once they get going don’t they! Ours are fruiting again now. We’ve started pickling them as we have so much jam! So pleased you liked it. Enjoy.

  5. Warren Sullivan

    Hi iam just about to make some jam for the first time before I start I have a question? What size jars do you need to make 500 gems of Cumquats?
    Warren

  6. HI Warren, it should make about 1.2-1.4 litres…..we use whatever size bottles we can find around the house. Usually they would be about 385g each and we’d fill about 4 of those.

  7. It’s my first time making a jam and your recipe is just so simple and it gives an awesome result. Thanks heaps!
    Just a question about the shelf life…how long can I keep it in the fridge?
    Thanks again xox

  8. Hi Jeanne, that is awesome, I am so pleased! Seriously, it will last for ages. If you sterilise the bottles really well and seal well, it will keep for years in the refrigerator.

  9. Hi Gavin, as someone who has definitely made jam from 5 kg (and more) the answer is yes, you need to use everything that comes from the fruit you are using. Good luck.

  10. First of all thanks for the great ” CUMQUAT “recipe. We are spending 2 months in Fiji and our friend brought us cumquats from next door telling me the ladies here make jam. Found your recipe easy and straight forward to follow. The results are fantastic jam . I just finished making and have tried it on a fresh roll, wonderful colour and flavor. Thanks again..

  11. HI MaryAnn, thanks so much for taking the time to write about the wonderful Cumquat :).. What a great story. We love it because it’s not something you see everyday!

  12. HI MaryAnn, thanks so much for taking the time to write about the wonderful Cumquat :).. What a great story. We love it because it’s not something you see everyday!

  13. I have a question, is the cup of sugar for the original 500gms of whole fruit or the weight of the fruit after sitting overnight?

  14. Hi Jenny, I’ve mentioned that it’s before the cooking process but understand that might be a bit confusing so I will edit it to make it a bit clearer. Once you have processed the fruit and it has sat overnight, use this to determine your sugar measurements, not the original fruit.

  15. Hey there .. I’ve done Step 1. & now is sitting over night .. when I go to cook in morning do I drain off the liquid that the fruit is sitting in before I measure it?? Wow it is Time consuming they are little nuggets ? .. took me 3hrs to prep the Cumquats for step 1

  16. Hi there I just finished making this lovely cumquet jam using 1kg of cumquet and thanks to my hubby with green thumbs, planted a cumquet tree in our back yard garden and right now bearing lots of fruit and what could be nicer having this jam and fresh bread for breakfast. Thank you for the recipe and having followed the same except as mentioned I used 1kg cumquet and also while the jam was in the cooking process something cropped up my mind..my younger daughter added 1 star aniseed and 1 cinnamon stick in her jam she prepared last time so I did the same..wow taste is so unique.Thanks again.

  17. Hi Veena, you will have so much wonderful fruit now! Our tree has not stopped bearing for about 15 years. Totally get the star anise and cinnamon. I actually have a downloadable ebook that you can buy at the bottom of the recipe that has 10 cumquat recipes in it. There’s actually several recipes that include these ingredients! They work perfectly with cumquat.

  18. Recipe sounds great. But I am a bit confused as cumquat has no pith. And the pictures suggest that the fruit is being blitzed with the skin on. So where is the pith that has to be cut out and soaked????

  19. HI Krisha, thanks for your message. Cumquat absolutely has pith. It’s easiest to remove it if you cut into quarters as I have shown (ie not into wagon wheels). By cutting into quarters you can see the pith running along the edge of the quarter (on the inside). This is also where you find the seeds. You need to slice a thin piece of the edge of the quartered fruit to get the pith. You can see the pith and seeds in the photos I have in the recipe. You are correct, the fruit is then being processed with the skin on but at this stage, the pith has been removed. If you look at the early photos before the pith has been removed you will see white in the centre. This is not evident on the fruit in the processer as it has been removed in the previous step.

  20. Love love love this jam. Preparation is tedious but definitely worth the effort. So delicious. Best I have ever tasted.

  21. Hi Kathy, yes I couldn’t agree with you more on both points. It is soooo tedious to prepare but it’s definitely worth it! Thanks so much for giving our recipe a go.

  22. Waked out to my backyard, looked at my cumquat in a big tub and thought, “hey, this year I’m using them”, hunted out your recipe and made it up. Mine isn’t a orange colour , more golden yellow, and it knocks your socks off with the taste. I cheated and did not use the seeds in the way you showed, but used jam sugar which has pectin in it, and which is made by CSR sugar (Australia). I use it for blood orange marmalade as nowadays I just can’t get the pectin measure correct in things.
    I liked it so much I went and picked more off the bush and will have to give it much more respect than I have done before!

  23. That is awesome Heather! Thanks so much for letting me know how you went. I’ve used pectin sugar before, though not with my cumquats. It would certainly make it much easier. I can see my cumquats starting to show on my tree now so it will be jam making time again soon.

  24. MyTien Lazzarotto

    I just finished making kumquat jam following your recipe. It tastes so goooood ?. I found that when adding just enough water to cover the pith and seeds, when boiling, all the juice evaporated after a couple of minutes. I added a bit of water in however I did not collect much juice after 10mns and so I used a teaspoon to press on the cooked pith and seeds in the strainer. Other than that, everything went well. My tip to make the process of cutting the kumquat less tedious is to cut into quarter with a knife then use scissors to cut the piths and remove seeds ?. Thank you for this recipe. I will definitely make again ?

  25. Hi, thanks for your comments. I can’t say that I’ve ever had an issue with the juice evaporating though and I have made this recipe many, many times. Still, this proves that everything is natural and doesn’t always work the same way. Good tip re the scissors. I’m pleased it worked for you. Re why your comment wasn’t posted, probably because we are in different time zones.

  26. HI Caroline, I always leave mine. As it goes through the rolling boil, the fruit bubbles up to the top and looks like scum. AS it settles in the jars, I don’t have any scum at all, just jam.

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