Lavender Milk

Warm milk with something botanical stirred into it is one of the oldest comfort drinks there is, and almost every kitchen has a version. India has golden milk, turmeric and pepper simmered into whole milk, which the cafes rediscovered and renamed the turmeric latte. The same cafes went on to moon milk, warm and spiced and sold as a way to end the day. Malaysia and Singapore have bandung, rose syrup and evaporated milk, poured a startling pink. Thailand pours butterfly pea into milk tea. The Philippines gave the rest of the world the ube latte, and bubble tea shops gave it taro. Spain and Mexico have horchata.

They are all the same idea. Take something floral or spiced or nutty, put it in milk, and drink it slowly.

Ours belongs in that company, and it does one thing none of the others do. It changes colour in front of you, and it changes in the unexpected direction.

Why it turns violet

Butterfly pea flower is a natural pH indicator. Most people meet it in a bar, where a blue drink goes pink the moment a lemon hits it. Our syrup starts at the other end. It carries a little citric acid, which is what lets it sit on a shelf instead of in your fridge, and that acid holds the butterfly pea at the red end of its range. That is why the bottle pours a deep ruby.

Milk is close to neutral and it resists being pushed around, far more than water or soda does. Stir a measure of an acidic ruby syrup into a whole mug of it and the milk wins. The pH climbs back up, the butterfly pea swings the other way, and the red blooms into a soft lavender violet. It is the same chemistry as the lemon trick, run backwards, and it lands on the exact colour the flower is named for.

No dye. Nothing added. Just the same pigment, reading a different room.

The one trick

Add the syrup to the milk, not the milk to the syrup. A splash of milk falling into a glass of neat acidic syrup is the one way to make it curdle. A measure of syrup going into a full mug of warm milk is not, because there is far more milk than acid and the milk holds its own comfortably.

Keep the heat gentle and stop at steaming. Boiled milk catches, and heat plus acid is harder on it than either alone.

Whole dairy gives the best colour and the most reliable result. Oat and almond milk work, but they are thin on the buffering that makes this behave, so add the syrup slowly and expect a paler violet. Barista-formulated plant milks handle it better than the standard ones.

Make it yours

A pinch of flaky salt sharpens the lavender and is worth doing once before you decide against it. Nutmeg or cardamom pushes it toward moon milk. A spoonful of honey suits it if your lavender is on the bold side, and ours is: we grow Grosso, a lavandin, and it carries.

For the iced version, pour it over ice as an Okanagan Blue. For the caffeinated one, add espresso and you have an iced lavender latte. Start from a bottle of Bench & Bloom, or make a batch of lavender simple syrup at home, which sets blue instead and does the trick the usual way round.