Milk First or Milk Second - Does it alter the taste?

Does Tea Taste Different If You Add Milk First or Second?

This simple question evokes strong responses.   

Inspired by a pioneering experiment from 1935, we decided to test this, and our results are detailed further down this page. But let’s start by understanding the background of the early scientific experiment on this topic.

The 1935 Experiment

British statistician Ronald Fisher and biochemist William Roach experimented to see if passionate tea drinker and biologist Blanche Muriel Bristol could taste the difference across multiple cups of tea.  Fisher often used sensory evaluation to illustrate statistical concepts so tea tasting offered a great subject matter. 

Blanche always added milk second and was confident she could taste the difference if it was added first.  Fishers, analytical view was that since the final temperature and relative proportions were identical, the order doesn’t matter, they should taste the same.

The experiment was to see if Bristol could distinguish, which four of the eight randomly ordered cups of black tea, had milk added first and which added second. 

The experiment was included in a Fisher-authored book published in 1935, called The Design of Experiments. As the story goes, biologist and tea lover Bristol could distinguish the differences.    

Our Stir Tea Experiment

We recreated a scaled-down version of the experiment at Stir HQ. We brewed four identical cups of Assam tea, serving them to Michelle for a blind tasting in identical white cups; two with milk added first and two with milk added second.

The parameters we tested under along with our observations:

• Measure of Tea:  3.50 gms of loose-leaf Assam black tea per 250 ml cup 
• Preparation Method: Boiling Water, steep for 4 minutes, prepared in a 1200 ml teapot
• Milk – Full fat, organic milk, 30 mls per 250 ml cup
• Pictured – Top line shows milk in first tea, second line shows milk in second.

Stir Tea Results

Michelle was able to identify a difference and group the cups into two different sets.  She commented that she really had to tune her senses in to do this – it wasn’t obvious from the liquor colour or temperature but the texture of the liquor.  There was a noticeable difference in mouthfeel for two of the cups, a creamier sense in the mouth which came from adding the milk first and perhaps is explained by the fact the milk was able to temper and integrate more.     

In Conclusion

The outcome of any experiment like this is very subjective.  Individual tastes and flavour preferences dominate however it is very interesting to explore how the sequencing of an action – milk first, milk second can impact on our overall tea experience.  Try it for yourself.