Why Does This Happen To My Cup?

[barry1010]

I drink the same coffee (instant) in the same cup (hands off, it's mine!) with the same milk every time.

Sometimes my cup is badly stained after one cup; other times there is no staining at all.

Why?

[Old_Geezer]

Maybe not all the instant coffee dissolves properly sometimes.

[douglas9401]

Does it happen when contents are contained or when your cup runneth over?

[albaqwerty]

Not all coffee is the same....

[barry1010]

It happens with coffee from the same jar; one spoonful stains,  the next doesn't 

[gingejbee]

Could it be that the cup is thoroughly washed after some uses, but only rinsed after others?...so that a small film of milk fat remains, onto which amounts of suspended coffee material sticks. That's my best offer!

[1581960]

Might be the temperature of the water/milk that is the variable.

[albaqwerty]

Do you drink each cup within the same time frame?

I'll be going down the silly suggestion route soon :))

[barry1010]

That could be the answer, ginge. I will experiment throughout tomorrow 

[Khandro]

barry; The only 3 variables are the milk (ugh!), because it comes from different cows, the water, and the spoon. 

1. All things are in flux.

2. No man can stand in the same river twice, for it is never the same river and he is never the same man.

Heraclitus.   🙂

[curlyfries81]

I find this happens with my tea if I leave it anywhere near a fan or a draught. 

[albaqwerty]

I hope Heraclitus is pronounced a particular way.

My inner child want to play, but I've grounded her.

[vulcan42]

Delving into my school memories we were told it was pronounced Hear are cly tuss but perhaps that was due to the master being very aware how smutty little boys are.

[netherfield]

Now there's a thing, sometimes in summer midst gardening we'll have a mug of tea outside on the table. That always seems to leave a stain down the inside of the mug. Never does it inside the house.

[albaqwerty]

Thanks Vulcan. 

I went with Herr a Clee tus, capitals not my doing. Am better with Latin than Greek and am hoping Herr was a Greek philosopher  :)

[calda49]

I have the same problem. I think it has some thing to do with how long you take to drink your coffee. If I drink it quickly it doesn't happen, but if I take sips while doing a crossword or composing an email, then I will get staining.