Blackberry and Raspberry Smoothie

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A blackberry and raspberry smoothie takes four ingredients and about two minutes: frozen blackberries, frozen raspberries, non-fat milk and a drop of vanilla essence, blitzed until smooth. Using the berries straight from the freezer is the whole trick, because they chill the drink and thicken it at the same time, so you never need ice and the flavour never gets watered down.It makes four good cupfuls at around 130 calories a cup, which puts it somewhere between a drink and a very light breakfast. Almost fat-free too, if you stay with the non-fat milk.Updated August 2026. The recipe itself has not changed. What I have added is the part the original post skipped. The seed grit, the dairy-free version, how thick it should actually be, and whether you can make it the night before.The printable card sits at the bottom of the page.

Why I pair these two berries

Blackberries on their own make a smoothie that is dark and faintly tannic. Raspberries on their own go thin and sharp. Together they land where I want them, sweet enough to drink without adding sugar and sour enough that you finish the glass. The health side is a bonus, and each berry earns a paragraph of its own.

Blackberries

Blackberries are full of vitamin C and high in fibre. Vitamin C supports the immune system and helps us recover from illness quicker. Fibre helps with cholesterol and with feeling full for longer, which matters more here than the calorie count does when breakfast is something you drink. One cup of blackberries also provides over a third of the daily requirement of vitamin K, which does the quiet work of blood clotting and bone strength.

Raspberries

Raspberries do a similar job and bring antioxidants and gallic acid on top, both of which support the immune system as we get older. They also carry more perfume than blackberries do. Blitzed together you smell the raspberries first and taste the blackberries last, and that is a better glass than either berry gives you alone.

What you need

Only 4 ingredients for this super low-calorie blackberry and raspberry smoothie. You can make 4 good cupfuls with just 300 grams frozen blackberries, 200 grams frozen raspberries, 600 ml of non-fat milk, and a touch of vanilla essence. That’s it.

The vanilla is the one people leave out and the one I would keep. A teaspoon does not make the drink taste of vanilla. It rounds off the sharp edge of the raspberries, so the whole glass reads sweeter than it really is.

How I blend it

Use a food processor if you have one. If not a stick blender will do. Just remember that the stick blender may take a little while longer because the fruit is frozen. If using a stick blender also use an oversized bowl, which will save you scrubbing purple spots off the tiles.

Stir the vanilla into the milk before the fruit goes anywhere near the jug. It takes two seconds and it spreads the vanilla through the whole drink, so no single mouthful gets all of it. Then pour the milk in first and pile the frozen fruit on top. Blades drag liquid down and push frozen fruit up, so a jug loaded in that order blends without you stopping every few seconds to poke at it.

Getting the texture right

Straight out of the blender this pours like a thick milkshake and holds a swirl on the surface for a second or two. That is where I want it.

Too thick to pull through a straw? Loosen it with milk, 50 ml at a time. Do not reach for water. It flattens the flavour.

Too thin? Either the fruit went in fresh, or it sat out on the worktop while you hunted for the blender. Ten minutes in the freezer will firm the glass up, and next time hold back 100 ml of the milk until the end.

Grit is the part no setting on the blender will solve. Blackberry and raspberry seeds are hard, small and far too numerous for a domestic blender to break down, so even a long blitz leaves a faint rasp on the tongue. Most people never register it. If it bothers you, push the finished smoothie through a fine sieve with the back of a ladle. You lose volume and you lose the fibre along with the seeds, so weigh that up before you reach for the sieve.

Swaps that work

Dairy-free. Oat milk is the closest match, sweet on its own and thick enough to carry the fruit. Almond milk works but comes out noticeably thinner and turns the finish slightly nutty. Coconut drink simply talks over the raspberries.

Fresh fruit. It works. The drink just comes out thinner, barely cold, and gone in three gulps. If fresh is what you have in the house, spread it on a tray and freeze it for a couple of hours first.

Other berries. Blueberries in place of the blackberries give you a milder, sweeter glass. Strawberries make it thinner and paler. Keep the raspberries whatever else you change, because they are doing the heavy lifting on flavour.

Something more filling. A tablespoon of chia seeds or a spoonful of plain yoghurt turns this from a drink into breakfast. Both push the calorie count up, so if the low count is the reason you are here, leave them where they are.

Making it ahead

It keeps in the fridge for a day in a sealed bottle, filled right to the top so there is as little air in there as possible. It will separate while it sits, a paler band of milk rising and the fruit settling underneath. That is normal, and a hard shake puts it back together.

Past 24 hours it goes downhill. The vitamin C fades, the fruit oxidises and the colour drifts from purple towards brown, which is the point at which nobody in my house will drink it.

Freezer packs are the version I actually use. Bag the fruit up a batch at a time, both berries together in one freezer bag, flattened out, four or five bags done in one go. On a weekday morning you tip a bag into the blender, add the milk and vanilla, and the whole job takes about as long as the kettle.

Nutritional values

The panel below covers one cup of the four this recipe makes, using non-fat milk.

Printable recipe

 

Questions I get asked about this one

Can I use fresh berries instead of frozen?
Yes, but the drink comes out thinner and barely cold, so freeze the fruit on a tray for a couple of hours first if you have the time.

Why is my blackberry smoothie gritty?
That is the berry seeds. No domestic blender breaks them down, so sieve the finished drink if the texture bothers you.

Can I make it dairy-free?
Oat milk swaps in one for one and is the closest to the original. Almond milk works and comes out thinner.

How do I make it thicker?
Hold back some of the milk and add it only if you need it. Frozen fruit and less liquid is the whole answer.

Can I make it the night before?
Yes, in a sealed bottle filled to the top, and shake it hard before you drink it. It separates overnight but comes back together.

Is it really that low in calories?
The 130 is for one of the four cups, made with non-fat milk and nothing else added. Semi-skimmed milk, yoghurt or seeds all push it higher.

Where to go next

Four ingredients, one blender, four cups of something cold and purple with nothing in it you did not put there yourself. Give it a go at home and let me know how you get on in the comments box below.

If this one suits you, the Raspberry and Pineapple Smoothie takes the same raspberries somewhere sharper, the Cherry and Chia Seed Smoothie is the thicker and more filling end of the range, and the Green Tea, Raspberry and Banana Smoothie is what I make when I want the caffeine without the coffee.

There is a whole page of them. Have a look at the smoothie page by clicking the photo below, and bookmark it while you are there, because I keep adding to it.

Until the next healthy smoothie… Steve.