# Strange Phenomenon



## fluffles (Sep 4, 2012)

OK, this has been puzzling me for a while and I'd like to know if anyone else has experienced this or can offer an explanation.

I have been drinking brewed coffee for years now. I brew with either Aeropress or Kalita Wave. My usual routine is to brew it in the morning and take to work in a thermos to drink at about 10:30 in the morning. I've noticed that doing this makes the coffee taste a lot nicer than when I brew and drink immediately.

It's definitely not to do with temperature because I always let my brewed coffee cool to bring out the flavours. I can only describe it as having a far more balanced and complex taste. My immediate brews are, in comparison, flat and dull with less acidity.

Something must be happening inside that Thermos but I cannot think what it could be. There are precious few grounds in there as I filter the Aeropress with paper.


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## The Systemic Kid (Nov 23, 2012)

What type of Thermos do you use - stainless steel lined or glass?


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## MWJB (Feb 28, 2012)

Assuming the method is the same for brews drunk immediately vs those that go in the thermos, I have a couple of theories...

As the drip brew is made you can get noticable layering, first issue is oily, reducing as the brew progresses & in the cup/carafe as it cools, the oils float nearer the top and the less oily stage of extraction sinks to the bottom. Maybe brewing in the thermos, retaining heat better than an uncovered cup/carafe allows more time/agitation for the stratification to even out/stop the layering from becoming such an issue as viscosity of the oils is reduced with the higher holding temp?

Material of the thermos might also be shifting the flavour?


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## beebah (Apr 1, 2012)

The aeropress can let fine particles through into the brew, perhaps it carries on extracting in the thermos?


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## fluffles (Sep 4, 2012)

I brew from aeropress into a stainless steel milk jug, which I then decant into the thermos. It's a metal thermos... would assume it's stainless steel though couldn't say for sure.

Not only is the thermos version tastier, I also regularly get close to tasting notes that come with the coffee.

Tomorrow, will try this: brew into thermos as normal, close the cap and give it a good shake and sit for a few minutes. Will then pour a little bit out and taste to see if the short time in the Thermos has made any difference.


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## michaelg (Jul 25, 2013)

I'm sure you would anyway but just in case I would say to cautiously unscrew to release the gas between shakes or you risk a ruined shirt! Maybe a prolonged vigorous stirring might have the same effect?


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## DavecUK (Aug 6, 2013)

Do you drink the coffee with milk?


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