Colour changing gin is the closest thing your drinks cabinet will ever get to a magic trick: a gin that sits deep, glacial blue in the bottle, then blushes pink the moment the tonic goes in. There is no sleight of hand and nothing artificial behind it, just a remarkable little flower and some friendly, edible chemistry. In this guide we'll cover what colour changing gin actually is, the science that makes it switch, how to make five bottles of your own with our Colour Changing Gin Kit, which mixers set off the change, and how to serve it so the transformation happens right in front of your guests, which is exactly where it belongs.
What is colour changing gin?
Colour changing gin, sometimes called magic gin or colour change gin, is a gin that has been infused with blue pea flowers. The flowers lend the spirit a striking blue, and that blue is not fixed. Add something acidic, a good tonic being the classic choice, and the whole glass shifts to pink or purple before your eyes. The change happens almost instantly as the mixer goes in, and once it has changed, it stays changed.
You may have spotted commercial versions behind fashionable bars. Making your own is more satisfying by a country mile, partly because watching the colour bloom through the bottle is half the fun, and partly because a blue gin that turns pink is one of those rare things that works equally well as a gift, a party trick and a genuinely good G&T.
How does the magic actually work?
The secret is the blue pea flower, also known as the butterfly pea flower, whose petals are rich in anthocyanins. Anthocyanins are the same family of natural pigments that colour blueberries, blackberries and red cabbage, and they have a party piece of their own: their colour depends on pH. In a neutral liquid, such as a plain gin, they sit a deep blue. Introduce acid and the pigment's structure shifts, and the colour shifts with it, sliding through purple towards pink.
That is the entire trick. Tonic water is mildly acidic, so the moment it meets the blue gin, the anthocyanins respond and the drink transforms in the glass. Nothing synthetic, no additives, no dye from a lab. It's natural, not artificial: a flower doing what it has always done, just somewhere more glamorous than usual.
How do you make colour changing gin at home?
This is where the kit earns its keep, because the method is gloriously simple and very hard to get wrong.
- Start with a plain, uncoloured gin you like the taste of. The base matters more than you'd think: coloured gins mask the effect, and flavoured gins are often more acidic, which can set the change off early. Plain and simple wins.
- Add 8 to 10 blue pea flowers to a 700ml bottle. Drop them straight in for the strongest colour, or use a paper filter bag if you'd like a tidier infusion.
- Seal, shake and leave for about 12 hours. Overnight is perfect: flowers in after dinner, blue gin by breakfast.
- Add 1 tsp of the Earl Grey infusion for the final hour, if you fancy it. This step is entirely optional, a little extra flourish for the curious.
- Strain, bottle and admire. Stored sealed and out of direct sunlight, the finished gin keeps for up to a year.
The kit makes five 700ml bottles in all, and there's no need to make them all at once. One for your own shelf, one for the next celebration, and three for the people who taste it and immediately ask where on earth it came from.
What's the best way to serve a colour change gin?
In front of an audience, always. Because the transformation happens in seconds and doesn't reverse, the magic is in the pour, so never mix this one quietly in the kitchen. Build the drink at the table instead: plenty of ice, a generous measure of blue gin, then the tonic poured slowly while everyone watches the colour chase itself around the glass. It's the kind of moment people reach for their phones over, and honestly, we'd be a little disappointed if they didn't.
A classic G&T serve suits it beautifully: good tonic, lots of ice and a citrus garnish, which has the happy side effect of nudging the acidity along. If you're trying a new mixer, test a drop with the pipette on a small measure first, so the big reveal goes exactly to plan.
Which mixers make the colour change?
Any acidic mixer will trigger the change, and one simple rule governs the show: the more acidic the mixer, the more dramatic the shift.
- Tonic water is the classic, reliable and elegant. Choose a proper tonic rather than a diet one, because some diet tonics aren't acidic enough to flip the colour.
- Lemonade works well and leans the drink a little sweeter.
- Soda water with a squeeze of lemon gives you a lighter serve, with the lemon supplying the acidity the soda lacks.
Whatever you choose, a squeeze of fresh lemon over the finished drink pushes the acidity further, which makes garnishing feel less like decoration and more like stagecraft.
Why isn't my gin changing colour?
Nine times out of ten, the answer is acidity, or rather the lack of it. The change only happens when something acidic meets the gin, so if your glass is stubbornly staying blue, work through this short list:
- Check your tonic. Some diet and slimline tonics simply aren't acidic enough. Switch to a regular tonic and try again.
- Add a squeeze of lemon. A little citrus is usually all it takes to wake the colour up.
- Test before you pour. Use the pipette to try your mixer on a drop of gin before serving, so you know the magic will land on the night.
And if the colour misbehaved from the very start, look at the base gin. A coloured gin will mask the effect entirely, and a flavoured gin is often acidic enough to set the change off early, leaving nothing in reserve for the tonic. A plain, uncoloured gin keeps the blue safely stored until showtime.
Who does a magic gin kit delight?
Almost everyone, in our experience, but a few people especially. Gift-hunters first: the Colour Changing Gin Kit solves the perennial problem of the person who has everything, because they almost certainly don't have a gin that changes colour on command. Hosts second: birthdays, hen parties, Christmas drinks and anniversaries all improve measurably when the drinks arrive with their own special effects. And gin lovers third, because underneath the theatre this is still a proper gin serve that happens to come with a story attached. Like everything we make, the kit is hand-packed in Britain, and UK delivery is free on orders over £25.
If the making appeals as much as the magic, there's further to go. Our Gin Making Kit starts a step earlier, turning a bottle of inexpensive vodka into a London-style gin with juniper and botanicals in under a week. And the Ultimate Gin Making Kit is the full apprenticeship: 13 premium botanicals, enough for up to ten 700ml bottles, and the freedom to blend signature gins of your own.
Colour changing gin FAQs
Is the colour change natural?
Completely. The colour comes from blue pea flowers, whose natural pigment changes with pH: blue in the neutral spirit, pink or purple once something acidic like tonic is added. Nothing artificial is involved.
How long does colour changing gin keep?
Once strained and bottled, it keeps for up to a year. Store it sealed and out of direct sunlight, though we suspect it won't be around anywhere near that long.
Does the colour change back to blue?
No. The change happens almost instantly when the mixer goes in, and it stays changed. That's why the magic is in the pour: change the colour in front of your guests, not before.
Can I use pink or flavoured gin as the base?
Best not to. Coloured gins mask the effect, and flavoured gins are often more acidic, which can trigger the change too early. A plain, uncoloured gin you enjoy the taste of is the one to use.
Can I make a non-alcoholic colour changing drink?
Yes, with a blue pea flower syrup. Warm 350ml of water with 350g of sugar until dissolved and steaming, around 90°C, then take the pan off the heat, add 10 blue pea flowers and steep for 30 minutes. Strain, bottle and keep it in the fridge, where it lasts for a month. Poured over ice and topped with lemonade, it turns from blue to pink right up the glass.
How many bottles does the kit make?
Five 700ml bottles, each made from a bottle of plain gin. There's no rush, either: the kit has a shelf life of about a year, so you can spread the batches out and enjoy every pour.
Ready to pour a little magic? Browse our gin making kits and make your next G&T the one everyone remembers.
