Custard-Base Ice Cream
Cooking Skills: Ice Cream 1
Chapter 3 · Custard-Base Ice Cream
Skill goal
Cook a custard safely, chill it and freeze it into four rich custard-based ice creams.
Shopping list for this chapter
The basics
Custard ice cream starts with a cooked custard: milk, cream, egg yolks and sugar heated gently until they thicken. The yolks act as an emulsifier, holding the fat and water together, which is why custard ice cream is richer and smoother than no-churn. Cooking the eggs also makes it safe: there is no raw egg.
The method
- Warm the milk first, and add it to the yolks slowly so they warm gradually rather than curdling.
- Cook low and stir constantly, in a clean pan, until it coats the back of a spoon. A finger drawn across the spoon should leave a clear line.
- Never boil: above about 85°C the egg scrambles. If it starts to lump, take it off the heat at once and whisk or blend it, then strain.
- Strain and cool fast, then chill for at least 4 hours: a very cold base freezes with smaller crystals.
- Spare whites: freeze them or use them for meringues (Cooking Skills: Eggs 2).
| Stage | What you see | What to do |
|---|---|---|
| Warm | Steaming, small bubbles at the edge | Turn off before it boils |
| Thickening | Slightly thicker, glossy; coats the spoon | Take it off the heat; strain |
| Too far | Small lumps or a curdled look | Whisk or blend hard; strain; use the ice cream anyway |
Custard, eggs, hot milk and allergens
Cooking the custard: stir constantly over a low heat until it coats the back of a spoon and leaves a clear line when you draw a finger across it. With a thermometer this is about 75 to 80°C, and it must never go above about 85°C or the eggs scramble (general guidance). Never boil it. Strain it and cool it quickly: stand the bowl in iced water, and refrigerate within about 1 hour. Cooked custard ice cream is best eaten within about 1 week (general guidance). Check current FSA advice if serving to pregnant women or other vulnerable people.Eggs: use eggs with the British Lion mark and wash your hands after handling raw egg. This course never serves raw egg: custards are cooked, and the no-churn and sorbet recipes have none. Pregnant women, babies, older people and anyone unwell should check current FSA advice before eating egg dishes, even cooked custard.
Hot sugar syrup and custard: sugar syrup is much hotter than boiling water and sticks to skin, so keep the pan handle turned in and don't touch it. Don't let anything boil over, and keep children away from the hob.
Allergens: ice cream usually contains milk (cream, condensed milk), and often egg, nuts, peanuts, soy (in some chocolate and cookies) and wheat (cookies and cones). Check labels, and never serve a nut-containing ice cream to someone with a nut allergy without telling them. Coconut cream or oat cream can replace dairy cream in some recipes, but the texture changes.
Try it
Level 1 · Start here
Vanilla custard ice cream
The classic: milk and cream, egg yolks and sugar, cooked gently into a custard, chilled and frozen. The yolks make it richer and smoother, and they hold the air and the water together so the crystals stay tiny.
Ingredients (5 portions)
- 300 ml whole milk
- 200 ml double cream
- 4 Lion-marked egg yolks
- 75 g caster sugar
- 1 tsp vanilla extract or paste (or half a vanilla pod, split and scraped)
- 1 pinch salt
- Heat the milk and cream (with the vanilla pod, if using) in a pan until just steaming. Don't boil.
- In a bowl whisk the yolks, sugar and salt together for 1 to 2 minutes until pale. Pour the hot milk onto the yolks a little at a time, whisking, so the yolks warm gently.
- Pour it all back into the clean pan and stir over a low heat for 5 to 8 minutes until it coats the back of the spoon (75 to 80°C). Don't let it boil.
- Strain through a sieve into a bowl, add the vanilla extract, and stand the bowl in iced water, stirring, until cool. Cover and chill for at least 4 hours or overnight.
- Freeze in a shallow tub, beating it every 30 to 45 minutes 3 or 4 times (about 4 hours), or churn in a machine for 20 to 30 minutes and freeze to firm up.
Custard, hot milk, eggs and allergens
Cooking the custard: stir constantly over a low heat until it coats the back of a spoon and leaves a clear line when you draw a finger across it. With a thermometer this is about 75 to 80°C, and it must never go above about 85°C or the eggs scramble (general guidance). Never boil it. Strain it and cool it quickly: stand the bowl in iced water, and refrigerate within about 1 hour. Cooked custard ice cream is best eaten within about 1 week (general guidance). Check current FSA advice if serving to pregnant women or other vulnerable people.Eggs: use eggs with the British Lion mark and wash your hands after handling raw egg. This course never serves raw egg: custards are cooked, and the no-churn and sorbet recipes have none. Pregnant women, babies, older people and anyone unwell should check current FSA advice before eating egg dishes, even cooked custard.
Hot sugar syrup and custard: sugar syrup is much hotter than boiling water and sticks to skin, so keep the pan handle turned in and don't touch it. Don't let anything boil over, and keep children away from the hob.
Allergens: ice cream usually contains milk (cream, condensed milk), and often egg, nuts, peanuts, soy (in some chocolate and cookies) and wheat (cookies and cones). Check labels, and never serve a nut-containing ice cream to someone with a nut allergy without telling them. Coconut cream or oat cream can replace dairy cream in some recipes, but the texture changes.
Level 2 · Flavour
Chocolate custard ice cream
Chocolate goes into the hot, strained custard and melts smoothly. The cocoa adds depth. This is a rich, dark ice cream that does not need many extras.
Ingredients (5 portions)
- 1 batch vanilla custard base (without the vanilla)
- 100 g dark chocolate (about 70%), finely chopped
- 2 tbsp cocoa powder, sifted
- 1 tsp vanilla extract
- Make the custard as above, but add the cocoa powder to the milk while heating and whisk smooth.
- Strain the cooked custard over the chopped chocolate and stir until completely melted and smooth. Add the vanilla.
- Cool in iced water, cover and chill for at least 4 hours.
- Freeze with beating or churning, as before.
Custard, eggs and allergens
Cooking the custard: stir constantly over a low heat until it coats the back of a spoon and leaves a clear line when you draw a finger across it. With a thermometer this is about 75 to 80°C, and it must never go above about 85°C or the eggs scramble (general guidance). Never boil it. Strain it and cool it quickly: stand the bowl in iced water, and refrigerate within about 1 hour. Cooked custard ice cream is best eaten within about 1 week (general guidance). Check current FSA advice if serving to pregnant women or other vulnerable people.Chocolate: chop it small so it melts fast in the hot custard, and check labels, as many dark chocolates contain soy and milk.
Allergens: ice cream usually contains milk (cream, condensed milk), and often egg, nuts, peanuts, soy (in some chocolate and cookies) and wheat (cookies and cones). Check labels, and never serve a nut-containing ice cream to someone with a nut allergy without telling them. Coconut cream or oat cream can replace dairy cream in some recipes, but the texture changes.
Level 2 · Flavour
Coffee custard ice cream
Dissolve the coffee in a spoonful of hot water, then stir it into the hot custard so it blends fully. Keep the sugar the same: coffee tastes bitter if it is under-sweetened.
Ingredients (5 portions)
- 1 batch vanilla custard base
- 2 tbsp instant coffee granules (decaf if you like)
- 1 tbsp hot water
- 1 pinch of salt
- Make the custard as in the vanilla recipe, leaving out the vanilla.
- Dissolve the coffee in the hot water and stir it into the strained, hot custard. Taste: it should be pleasantly bitter, not harsh.
- Cool in iced water and chill for at least 4 hours.
- Freeze with beating or churning.
Custard, eggs and caffeine
Cooking the custard: stir constantly over a low heat until it coats the back of a spoon and leaves a clear line when you draw a finger across it. With a thermometer this is about 75 to 80°C, and it must never go above about 85°C or the eggs scramble (general guidance). Never boil it. Strain it and cool it quickly: stand the bowl in iced water, and refrigerate within about 1 hour. Cooked custard ice cream is best eaten within about 1 week (general guidance). Check current FSA advice if serving to pregnant women or other vulnerable people.Coffee: coffee contains caffeine, so use decaffeinated instant coffee for an evening dessert or for children.
Eggs: use eggs with the British Lion mark and wash your hands after handling raw egg. This course never serves raw egg: custards are cooked, and the no-churn and sorbet recipes have none. Pregnant women, babies, older people and anyone unwell should check current FSA advice before eating egg dishes, even cooked custard.
Level 3 · Infusion
Honey and ginger custard ice cream
Warm the milk with sliced ginger and let it infuse for 15 minutes before making the custard: the flavour is gentle and warm. Honey replaces some sugar and adds floral sweetness, and it also keeps the ice cream a bit softer.
Ingredients (5 portions)
- 300 ml whole milk
- 200 ml double cream
- 2 cm fresh ginger, thinly sliced
- ½ tsp ground ginger
- 4 Lion-marked egg yolks
- 40 g caster sugar
- 4 tbsp runny honey
- 1 pinch salt
- Heat the milk, cream, sliced ginger and ground ginger until steaming. Turn off the heat, cover and leave for 15 minutes to infuse. Reheat gently until steaming.
- Whisk the yolks, sugar and salt, then add the hot, strained milk a little at a time, whisking.
- Cook over a low heat as before until it coats the spoon (75 to 80°C). Strain and stir in the honey while hot.
- Cool in iced water, chill for at least 4 hours and freeze with beating or churning.
Custard, eggs, honey and allergens
Cooking the custard: stir constantly over a low heat until it coats the back of a spoon and leaves a clear line when you draw a finger across it. With a thermometer this is about 75 to 80°C, and it must never go above about 85°C or the eggs scramble (general guidance). Never boil it. Strain it and cool it quickly: stand the bowl in iced water, and refrigerate within about 1 hour. Cooked custard ice cream is best eaten within about 1 week (general guidance). Check current FSA advice if serving to pregnant women or other vulnerable people.Honey: don't give honey to babies under 12 months.
Allergens: ice cream usually contains milk (cream, condensed milk), and often egg, nuts, peanuts, soy (in some chocolate and cookies) and wheat (cookies and cones). Check labels, and never serve a nut-containing ice cream to someone with a nut allergy without telling them. Coconut cream or oat cream can replace dairy cream in some recipes, but the texture changes.
Experiments
Experiment
Custard thickness
Just thickened or a little further.
- Cook a vanilla custard and take a small spoonful off at the moment it first coats the spoon (about 75°C). Cook the rest for another minute and take another. Cool and freeze both.
Look for: The first is thinner and creamy. The second is thicker and richer, but too much more and it starts to curdle. Note the sweet spot.
Experiment
Yolk amount
3, 4 or 5 yolks.
- Make small batches of the custard with 3, 4 and 5 yolks per 500 ml of milk and cream.
Look for: More yolks make a richer, denser, more custardy ice cream, while fewer give a lighter, cleaner one. Four is a good middle.
Experiment
Chill time
1 hour or overnight.
- Freeze one portion of the custard after 1 hour of chilling and another after chilling overnight.
Look for: The overnight-chilled custard freezes smoother with fewer ice crystals. A warm base freezes slowly and goes icy.
Experiment
Stir during freezing
Beating or churning.
- Freeze the custard with 3 or 4 beatings and, in another tub, with none.
Look for: The beaten tub is far smoother. The unstirred one is hard, with a layer of ice. If you have a machine, compare it with a hand-beaten batch.
Tasting notes
| What I tried | Method or amount | What I saw | What I thought | Will I do it again? |
|---|---|---|---|---|
| Vanilla custard | ||||
| Chocolate custard | ||||
| Coffee custard | ||||
| Honey and ginger | ||||
| Custard thickness | ||||
| Yolk amount | ||||
| Chill time | ||||
| Stirring while freezing |
Troubleshooting
| Problem | Likely cause | What to do |
|---|---|---|
| Scrambled custard | Too hot or not stirred | Take off the heat, whisk or blend, strain; cook lower next time |
| Thin custard | Not cooked enough | Cook a little longer over a low heat, stirring |
| Icy ice cream | Base not cold enough, or no stirring | Chill overnight; beat or churn |
| Eggy taste | Over-cooked, or too many yolks | Cook just to coat the spoon; use 4 yolks |
| Grainy chocolate | Chocolate not fully melted | Chop it small and stir until smooth in the hot custard |
| Won't freeze hard | Too much sugar or honey | Cut back a little; chill the tub in the freezer first |
Custard, eggs and allergens
Cooking the custard: stir constantly over a low heat until it coats the back of a spoon and leaves a clear line when you draw a finger across it. With a thermometer this is about 75 to 80°C, and it must never go above about 85°C or the eggs scramble (general guidance). Never boil it. Strain it and cool it quickly: stand the bowl in iced water, and refrigerate within about 1 hour. Cooked custard ice cream is best eaten within about 1 week (general guidance). Check current FSA advice if serving to pregnant women or other vulnerable people.Eggs: use eggs with the British Lion mark and wash your hands after handling raw egg. This course never serves raw egg: custards are cooked, and the no-churn and sorbet recipes have none. Pregnant women, babies, older people and anyone unwell should check current FSA advice before eating egg dishes, even cooked custard.
Allergens: ice cream usually contains milk (cream, condensed milk), and often egg, nuts, peanuts, soy (in some chocolate and cookies) and wheat (cookies and cones). Check labels, and never serve a nut-containing ice cream to someone with a nut allergy without telling them. Coconut cream or oat cream can replace dairy cream in some recipes, but the texture changes.
Checkpoint: can you do this now?
- I can cook a custard to coat the spoon without scrambling it.
- I can strain, cool and chill a custard base properly.
- I can infuse a flavour into the milk.
- I can freeze custard ice cream with or without a machine.
- I know why there is no raw egg in my ice cream.
Next chapter
Cooking Skills: Ice Cream 1, chapter 4 is Fruit Sorbets: balancing sugar and fruit for a light, dairy-free freeze.