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Glass bowl of marmalade, with a silver spoon in it, sitting on a wooden board, with a beige napkin to the left of the bowl. Half a grapefruit is sitting next to the bowl.

Grapefruit Marmalade

If you enjoy making your own condiments from seasonal produce, this soft set Grapefruit Marmalade is for you. Marmalade is a favoured preserve on many breakfast tables. It is easy to appreciate that this zesty, tangy preserve is a great way to start the day.
Course Condiments
Cuisine British
Prep Time 20 minutes
Cook Time 40 minutes
Inactive Time 12 hours
Total Time 13 hours
Servings 9 x 250 ml Jars
Calories 715kcal
Author Alexandra


  • 500 g (1 lb) grapefruit - prepared weight See Notes 1 and 2
  • 1 lemon
  • 6 cups (1.5 Litre) water
  • 8 cups (1.8 kg) sugar See Note 3


To Sterilise the Jars:

  • Sterilise the jars you'll be using to store the marmalade.
    Choose glass jars with an airtight, metal lid and ensure they have been washed in the dishwasher or by hand in hot soapy water then rinsed well.
    Check that the metal lids do not have rubber inserts. (See Note 9)
    Preheat the oven to 130 Degrees C (270 F) and place the jars in the oven for 15-20 minutes.

For the Marmalade:

  • Place 2 saucers or small plates in the freezer, ready to check for the setting point of your marmalade.
    Thoroughly wash the grapefruit and lemon. Remove each end of the grapefruit to get rid of excess pith. Remove each end of the lemon. Cut the grapefruit and lemon into quarters length ways. Holding two of the quarters together, slice as thinly as possible and remove any seeds.
  • Place the citrus slices in a non-reactive bowl. See Note 4.  Add the 6 cups of water, cover the bowl and leave the fruit to stand overnight, up to 24 hours. If your bowl is not large enough to accommodate all the water, add what you can and add the remainder the following day. It’s best to make a note of what you have added.
    The following day, place the fruit and water into a very large, non-reactive saucepan. – See Note 5.
  • Over medium-high heat, bring the fruit and water to the boil. Rapidly boil for approximately 15 minutes or until the peel is tender, stirring occasionally with a long-handled wooden spoon – See Note 6.
  • Add the sugar and stir well to dissolve it. After dissolving the sugar, return the fruit to the boil, stirring occasionally. Continue to stir until the marmalade reaches setting point - I start to check at about 10 minutes. When the very aggressive bubbles subside to a slower, gentler boil, that's an indication that your marmalade may have reached setting point – See Note 7.
    Remove from the heat to conduct the wrinkle test. If not set, continue to boil for another 1 minute and then test again.
  • To test for setting point, I use the “wrinkle” test. Take one of your saucers from the freezer and pour a small amount of marmalade onto it. Let it cool for a minute then push against the marmalade with the tip of your finger. If the surface wrinkles slightly, it means setting point has been reached.
    Alternatively, if you are not confident checking this way or are not experienced at making marmalade, you can use the fail-safe method of using a jam/candy thermometer which you clip to the side of your saucepan. When attaching your thermometer, make sure that the base is not touching the bottom of the saucepan. Your marmalade has reached setting point when the temperature reaches 104.5 degree C or 220 degrees F. 
    (Taking it much higher than this will result in the marmalade being overboiled, the pectin being destroyed, and therefore, your marmalade will not set.)
    At this time, your marmalade will look very liquidy - it can take 24-48 hours to completely cool and set.
    Please note, this recipe will produce marmalade which has a soft set; it will not be as firm as many commercial varieties which often contain additives.
  • Take the mixture off the heat. If there is any scum on the marmalade, add a teaspoon of butter and stir; that should settle the scum.
  • Let the marmalade stand for about 10 minutes to allow the fruit to settle. If you bottle it immediately, the fruit will not be evenly distributed but will settle at the top of the jar.
  • Remove your jars from the oven and carefully ladle the marmalade into the heated, sterilised jars. The jars should be filled as full as possible to minimise the amount of air between the marmalade and the lid. The marmalade should not touch the lid. Seal tight once filled with marmalade. See Note 8
    You need to be very careful. Splashing yourself with hot marmalade will result in a very serious burn. I suggest you have clothing with long sleeves and ensure that you do not have children nearby.



  1. I used 2 medium-large grapefruit to achieve the weight after the ends and seeds have been removed.
  2. As the peel is such an important part of the marmalade, I like to use organic or home-grown citrus. Commercially produced grapefruit and lemons generally have a wax coating and may have been sprayed with something toxic. If this is all that you can obtain, you can clean the grapefruit and lemons by placing them in a colander and pouring over freshly boiled water. Then, scrub them gently with a nail brush while holding them under cold running water.
  3. This may seem an excessive amount of sugar, however, this is not the usual fruit to sugar ratio. We use a large amount of water to soak the fruit. The water is included in the marmalade.so this means a larger amount of sugar.
  4. Non-reactive bowls and saucepans are stainless steel, glass, ceramic or enamelled cookware. Aluminium, copper and iron bowls or pans are reactive. Acidic foods, such as citrus, may discolour and take on a metallic taste if these are used.
  5. A large saucepan is essential. When you add the sugar, it foams up enormously. Without a very large saucepan, there is the risk of it boiling over.
  6. To stir, use a long-handled wooden spoon. Do not use metal, it will become dangerously hot.
  7. The boiling time may vary slightly depending on several factors, the thickness of your fruit slices, the width of your saucepan and the heat at which the fruit is boiled.
  8. Your marmalade will be very liquid when you add it to the jars so please don’t be concerned. It will continue to thicken as it cools. Leave it for 24-48 hours and then check again. If it is still runny, you can re-boil the marmalade. Empty the contents of the jars back into the saucepan and bring to a boil. To increase the pectin and help the marmalade to set, you can add the juice of half a lemon. Boil for a few minutes and test again.
    However, if the marmalade was initially boiled too long, it can still result in it not setting as the pectin may have been damaged.
  9. Properly sterilising your jars is an essential process to remove bacteria which could cause your preserves to spoil. I prefer to sterilise jars in the oven. To do this, preheat your oven to 130 Degrees C (270F).
    Use glass jars with an airtight, metal lid. If recycling jars, ensure that the jars do not have cracks or chips and the lids are in good condition. Discard any lids that are pitted or rusted.
    Wash the jars and lids either in the dishwasher or by hand in hot soapy water, and rinse well. Do not dry them with a tea towel. Place upright jars and lids on a baking tray. If you are using kilner jars with rubber seals, be sure to remove the seals before placing the jars in the oven. The dry heat of the oven would damage the seals. Boil the seals separately in a saucepan for about 10 minutes. Heat the jars in the oven for at least 20 minutes. When your preserves are ready to bottle, use thick oven mits or jar tongs to remove the jars. Do not place them on a cold surface as they may shatter. I place mine on a wooden chopping board which I cover with a tea towel. Always sterilise a few more jars than you think you will need. It is better to have too many jars than not enough.
  10. Please note, the nutritional information is based on one 250ml jar. The nutritional information is an estimate only.


Calories: 715kcal | Carbohydrates: 185g | Protein: 1g | Fat: 1g | Saturated Fat: 1g | Sodium: 10mg | Potassium: 92mg | Fiber: 1g | Sugar: 182g | Calcium: 22mg | Iron: 1mg