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Experimentbeginnerdraft

Lemon turns black tea pale

Also searched as: tea colour lemon, tea experiment

In short: A squeeze of lemon visibly lightens black tea; a pinch of baking soda makes it darker.

Picture it

Like a traffic light in a glass: the colour shows whether it is acidic or alkaline.

Before · Afterfresh tea
with lemon
plain
with soda
Schematic
You need · 5 minutes
  • freshly brewed black tea
  • three clear glasses
  • lemon juice
  • a pinch of baking soda

How it’s done

Sequence · Step 1 of 3
123

Divide the tea evenly between three glasses.

All steps as a list
  1. Divide the tea evenly between three glasses.
  2. Add a teaspoon of lemon juice to the first, a pinch of baking soda to the second, leave the third as it is.
  3. Stir and compare the colours.

What you see

With lemon the tea turns light orange, with baking soda dark red-brown.

Why it happens

The red and brown pigments in black tea change colour with the pH, much like red cabbage juice. Acid makes them lighter, a base darker.

Related entries
pH (acidic to alkaline)IndicatorRed cabbage colour magicBrewing tea properly
Sources · 1
  • Harold McGee: On Food and Cooking (2004), Kapitel Tee