Jam through vanilla

Blueberry ripple

Name: Blueberry ripple
Prep time: 25 min
Cook time: 15 min
Total time: 5 h
Yield: 1 litre (about 8 scoops)
Cuisine: American
Ingredients: 300 g (2 cups) blueberries, fresh or frozen; 60 g (⅓ cup) caster sugar; 1 tbsp lemon juice; A pinch of salt; 400 ml (1⅔ cups) double cream (heavy cream); 300 ml (1¼ cups) whole milk; 130 g (⅔ cup) caster sugar; 1 tsp vanilla extract; A good pinch of fine salt

A quick lemony blueberry jam rippled through a no-egg vanilla base. The trick is to cook the jam down properly and let it go completely cold, so it ribbons rather than bleeds.

Makes about 1 litre
25 min hands-on
Chill 4 hrs
Churn 20–30 min
No eggs

Illustration of a cup of blueberry ice cream

Ingredients

Makes about 1 litre (1 quart), roughly eight scoops.

For the ripple

300 g2 cups blueberries, fresh or frozen
60 g⅓ cup caster sugar
1 tbsp lemon juice
A pinch of salt

For the base

400 ml1⅔ cups double cream (heavy cream)
300 ml1¼ cups whole milk
130 g⅔ cup caster sugar
1 tsp vanilla extract
A good pinch of fine salt

Method

Make the jam first so it has time to go properly cold. Warm jam melts channels straight through the ice cream.

Cook the blueberries with the sugar, lemon juice and salt over a medium heat, squashing some of them, until thick and reduced by about a third, which takes 10 to 12 minutes. It should mound on a spoon.
Cool the jam completely, then chill it. This is not optional.
Stir the sugar and salt into the milk until fully dissolved: a good two minutes of whisking.
Stir in the cream and vanilla, and chill for at least 4 hours.
Churn for 20–30 minutes, until thick.
Pack in layers: a third of the ice cream, spoonfuls of cold jam, another third, more jam, the rest. Drag a knife through once.
Freeze for at least 4 hours before scooping.

Worth knowing

Stirring is the enemy of a ripple. One pass with a knife is all it takes; anything more and you have purple ice cream.
Cook the jam further than you think. A loose jam freezes into icy veins; a thick one stays soft and glossy.
Frozen blueberries are ideal here and cheaper. Cook them straight from frozen, allowing a few extra minutes.
Any leftover jam keeps in the fridge for a fortnight and is very good on toast.

Make it yours

Five ways to change it

Blackcurrant

Swap the blueberries for blackcurrants and add 20 g more sugar: they are much sharper.

Lemon blueberry

Add the zest of a lemon to the base as well as the juice to the jam.

Cheesecake ripple

Whisk 100 g cream cheese into the milk at step 3 and add a handful of crushed digestives at the end.

Bramble

Use blackberries, and add a splash of crème de cassis to the jam.

Blueberry and bay

Simmer a bay leaf with the jam, then fish it out. Herbal and unexpected.

If it goes wrong

Rescue remedies

The ripple froze into hard purple ice

The jam was too thin. Cook it down further, or stir a teaspoon of lemon juice or vodka into the finished jam to keep it soft.

The colour bled everywhere

The jam was warm, or you stirred rather than layered. Chill it hard and use a single knife pass.

The base tastes flat

Uncooked bases need more salt than you would expect, and the vanilla must be good.

Can I use shop-bought jam?

Yes, though it is usually looser and sweeter. Cook it down for a couple of minutes with a squeeze of lemon first.