Causing a stir

At around 11am every day, there is a long-standing debate in our office about the coffee making process and I wonder if any of your readers would be able to settle the matter once and for all.

When I make coffee I add the cold milk and then hold on to the mug and stir vigorously in a clockwise circular motion — creating a sort of vortex.

Unfortunately, one of my colleagues doesn’t agree with me. When he makes coffee, he takes the spoon and after adding the milk just places the spoon into the centre of the mug and gently makes two figures of eight. He says this method is more effective and I should adopt it. As the engineer in our office, he claims that his opinion is based on his superior knowledge.

I am no engineer and know nothing about viscosity of fluids and which would be the most effective method of mixing a cold fatty liquid into a hot thin one, but as this debate has been going on for the best part of 20 years I’d be glad to hear the opinion of someone who does know.

I realise that I am running the risk of engineers wanting to stick together on this one, but I believe the integrity and technical understanding of your readers will produce the correct answer.

Shirley Batten

TS Technology, Watford