Colour changing gin is gin, and it is as safe to drink as the bottle of gin you made it from. The colour comes from blue pea flowers, also called butterfly pea flowers, a flower long used to make tea, and the kit adds nothing artificial at all: no colourings, no sugars, no sweeteners. What you are drinking is a plain gin you bought, steeped with dried flowers and strained, with a pigment in it that reacts to acidity. The usual sense applies as with any spirit, and the kits are for adults aged 18 and over.
What is butterfly pea flower?
It is the flower of a climbing plant grown widely in South and South East Asia, deep blue and long used to make tea. In the kitchen it turns up in rice dishes, drinks and desserts wherever a strong blue is wanted, because the flower carries an unusually vivid pigment and gives it up readily to hot or cold liquid.
In our Colour Changing Gin Kit the flowers are dried, and they go into a bottle of plain gin. Roughly 8 to 10 flowers per 700ml bottle, either dropped straight in for the strongest colour or tucked into a paper filter bag for a tidier infusion. Seal it, shake it, and leave it about 12 hours. That is the whole of it, and there is nothing in the box that is not a dried botanical.
Why does the colour change?
Because the pigment in the flowers responds to pH. In the neutral spirit it reads as a deep blue. Introduce something acidic and the same pigment shifts towards pink or purple, and it does so almost the instant the mixer hits the glass.
That is a straightforward chemical reaction and not an additive doing a trick. It is also the reason the effect is reliable: a proper tonic, lemonade, or soda with a squeeze of lemon will all set it off, and the more acidic the mixer, the more dramatic the shift. Some diet tonics are not acidic enough to do much, which is the usual explanation when someone tells us their gin refused to change. Test a little with the pipette before you pour for guests, and add a squeeze of lemon if it needs help.
Is there any artificial colouring in it?
None. The colour is the flower's own pigment, which is why the drink goes blue in the first place and why it behaves the way it does with an acidic mixer. There are no sugars or sweeteners in the botanical blend either, so all the flavour comes from what is in the jar.
This is worth saying plainly because bright blue drinks have a reputation, and a lot of colour changing novelty products earn it. This one does not work like that. If you have ever brewed a pot of blue tea, you have already seen the same pigment doing the same thing.
What does it taste of?
It tastes of the gin you started with, plus whatever you choose to add. The kit pairs the blue pea flowers with an Earl Grey botanical infusion, and a teaspoon of that stirred in for the last hour of the steep is optional rather than compulsory. Add it if you want the bergamot note, leave it out if you want the colour and nothing else.
Because of that, the base gin matters more than usual. Use a plain, uncoloured gin that you actually like drinking. Coloured gins mask the effect, and flavoured gins are often more acidic, which can set the colour change off early and spoil the moment. A straightforward gin is the right choice here.
How strong is the finished gin?
Exactly as strong as the gin you poured in. Infusing does not dilute a spirit, so if the label on your bottle says 37.5%, your blue gin is 37.5% as well. Dried flowers do not change the alcohol content any more than a slice of lemon does.
That is worth remembering because the colour makes it look like a soft drink, particularly once it has gone pink over ice. Label the bottle, keep it with the other spirits rather than the cordials, and keep it away from children. Once strained and bottled it keeps up to a year, stored sealed and out of direct sunlight.
Can you make a version without alcohol?
Yes, and it works just as well, because the pigment does not care what it is dissolved in. Make a blue pea flower syrup instead: warm about 350ml of water with 350g of sugar until the sugar dissolves and the pan is steaming rather than boiling, take it off the heat, add around ten flowers and leave them to steep for half an hour, then strain and bottle it. It keeps for about a month in the fridge.
Pour the syrup over ice, top it with lemonade, and it turns from blue to pink up the side of the glass. It is a good option for anyone at the table who is not drinking, and the effect is identical.
Colour changing gin FAQs
Is colour changing gin safe to drink?
Yes. It is a plain gin you bought, infused with dried blue pea flowers and strained. Nothing artificial is added, and it is an adult drink like any other gin, for those aged 18 and over.
What makes colour changing gin blue?
Blue pea flowers, also known as butterfly pea flowers, a flower long used to make tea. Their own pigment colours the spirit, with no artificial colouring involved.
Why does it turn pink with tonic?
The pigment responds to pH. It reads blue in the neutral spirit and shifts to pink or purple when something acidic such as tonic is added, and the change happens almost instantly.
Why is my gin not changing colour?
The mixer is probably not acidic enough. Some diet tonics will not do it. Use a proper tonic, or add a squeeze of lemon, and test a small amount with the pipette before serving.
Can I use pink or flavoured gin as the base?
Better not to. Coloured gins mask the effect and flavoured gins are often acidic enough to trigger the change early. The kit works best with a plain, uncoloured gin you enjoy drinking.
Fancy making a bottle that changes in the glass? Take a look at our gin making kits.
