Rhubarb jam in the Thermomix® takes 25 minutes of active time, plus one hour of resting with the jam sugar. From 1 kg of rhubarb you get 4 jars of 250 ml. The secret boost: 20 g of amaretto at the end. It softens the acidity and adds an almond note that pairs perfectly with the fresh rhubarb flavour.
We make rhubarb jam every May, when the first stalks in the garden are ripe. The season is short (April to June in the UK and Germany), and a sealed jar keeps for at least a year. That way there is still rhubarb on your toast in February.
Rhubarb Jam in the Thermomix®
Ingredients 0 / 5 ✓
- 1 kg rhubarb
- 500 g 2:1 jam sugar
- 3 tsp vanilla extract or 2 sachets of vanilla sugar
- 15 g lemon juice
- 20 g amaretto optional
Instructions 0 / 5
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1
Prepare the rhubarb.
Rhubarb: wash, peel away the strings, cut into pieces of about 3 cm, place in the mixing bowl, chop for 10 seconds / speed 6 and push down with the spatula.
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2
Mix in the sugar.
Add the jam sugar, mix for 10 seconds / speed 3 and leave to rest for 1 hour.
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3
Cook the jam.
Add the vanilla extract or vanilla sugar and lemon juice and cook for 15 minutes / 100°C / speed 2. If the jam foams too much, reduce the temperature briefly.
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4
Sterilise the jars.
Meanwhile, sterilise jars and lids with boiling water. Do a set test, add the amaretto and mix for 10 seconds / speed 3.
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5
Fill the jars.
Fill the jam into the prepared jars, seal and leave to cool.
Tip: You can also mix rhubarb with raspberries or strawberries. This makes the jam even fruitier. Please note that the total quantity of fruit should not exceed 1 kg.
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Nutrition per serving
The one-hour rest is not optional
The rhubarb is first chopped for 10 seconds at speed 6, then the jam sugar goes in, mix briefly, and the whole thing rests for one hour at room temperature. During this time the sugar draws the water out of the rhubarb and dissolves into it. The result is a slightly liquid pulp that cooks evenly.
Skipping the resting time (which many Vorwerk community recipes do with 13 to 18 minutes of direct cooking) gives you an uneven jam. The sugar sinks to the bottom, the rhubarb floats on top, and the cooking either burns the sugar or leaves the rhubarb undercooked. The resting time is what sets our recipe apart from the faster direct-cook versions.
2:1 jam sugar is essential
Rhubarb contains 0.4 to 0.6 per cent pectin (German Nutrition Society, 2024). That is in the lower-middle range. With 1:1 jam sugar the ratio of 1 kg rhubarb to 1 kg sugar would simply be too sweet. With 2:1 (500 g sugar to 1 kg rhubarb) the characteristic tart note is preserved, and the jam still sets firmly.
If you try 3:1: possible with very tart early-season rhubarb, but risky. The pectin content in 3:1 jam sugar often is not enough, and the jam stays runny. For the Xucker jam-sugar alternative, use the 1:1 ratio (stated on the packaging).
Vanilla and lemon: the two supporting pillars
3 tsp of vanilla extract, or a scraped vanilla pod, turn a sharp rhubarb jam into a grown-up preserve. Vanilla rounds out the acidity without masking the flavour. The 15 g of lemon juice (about half a lemon) is not there for taste: it activates the pectin in the jam sugar.
Without lemon the jam will not set, even with jam sugar. That is chemistry, not flavour. The acidity (pH 2.4 in lemon juice) triggers the pectin cross-linking. If you have no fresh lemon: 1 tsp of citric acid powder or 15 g of lime juice works just as well.
Amaretto at the end: 20 g make all the difference
The amaretto goes in after cooking, not before. At 100°C the alcohol evaporates completely within 90 seconds (USDA data on alcohol loss during cooking, 2022). If you want the almond flavour to come through, add the amaretto in the last 10 seconds at speed 3, when the jam has cooled to around 80°C.
If you prefer no alcohol: 1 tsp of bitter almond extract or 1 tbsp of almond syrup as a substitute. Leaving it out entirely works too, but the result tastes noticeably flatter. The almond-rhubarb combination is one of the best jam pairings we know.
Strawberry and rhubarb jam: the most popular combination
If you want to combine rhubarb with strawberries (actually the most searched term in the Vorwerk community), use 500 g rhubarb plus 500 g strawberries with 500 g of 2:1 jam sugar and 30 g of lemon juice. Strawberries add sweetness and colour, rhubarb adds acidity and pectin. The ratio otherwise stays the same.
Chop both fruits together for 15 seconds at speed 5, leave to rest for 1 hour, then cook for 18 minutes at 100°C on reverse direction, speed 2. Reverse direction for this combination, otherwise the strawberries will be completely crushed and the typical chunky texture will be lost.
Spring rhubarb vs. summer rhubarb: which works better
Spring rhubarb (April to May) is mild, almost sweet, with green to pink stalks. Summer rhubarb (June) is more intense, more tart, often with red stalks. For jam we use spring rhubarb because the natural sweetness balances the amount of sugar needed.
Summer rhubarb works too, but needs 50 g more jam sugar (550 g instead of 500 g) and one extra tsp of vanilla to bind the acidity. The colour turns a more intense red, which looks attractive in a jar.
Rhubarb jam as a gift or alongside cheese
The jam works classically on toast with butter. We also use it as a topping for Greek yoghurt with granola, as a filling for Linzer biscuits or as a glaze for cheesecake. If you want to bake a cheesecake with rhubarb and crumble topping: the jam as a layer between the quark filling and the crumble gives a lovely sweet-and-sour balance.
It makes a great gift because the season is short and the jam is rarely bought ready-made. Pop it in a jar with a handwritten label (date, variety) and a red ribbon. Keeps for a year in sealed jars, and four weeks in the fridge once opened.
More jam inspiration from the mixing bowl
If you want to understand the pectin concept and the right jam sugar for each fruit: our basic jam recipe in the Thermomix® explains the theory. A classic with Cointreau: strawberry jam with Cointreau. Summer stone fruit: apricot jam. For sterilising jars via the Varoma: sterilising in the Thermomix®.
Goes well with: cream cheese, butter and bread rolls.
