Coffee, I wrote, must never be served
in a clear glass cup. It will taste richer
and more robust when served in an opaque
cup or mug (white is best). "It's
just simple physics."
It was a joke. I was kidding.
(Sorry!) I know about as much about physics
as I know about ... well, the nearly infinite
number of things I know almost nothing about
(though I do think the coffee LOOKS
darker/richer in an opaque mug, and hence I
am tricked into thinking it is).
But I loved your responses.
Dennis Pierson: I can't stand it
anymore. I've got to know why the opacity
of the container affects coffee. I believe you
said in your column that it was a basic law of
physics. Okay, so science was not my strong
suit — but I can't figure out what
difference it would make. I know I run the risk
of appearing really stupid if you were simply
being facetious (of course, it would not be the
first time ... or even the second) but I guess
I trust you more than I fear being naive (talk
about the lamb being led to slaughter). Please
answer this so I can have peace of mind while
running. It's practically all I've
thought about on my recent jogs.
Marc A. Armstrong: Nonsense. Black coffee
will taste hotter longer in whatever container is
the better insulator, and glass is a better
insulator than porcelain. It's simple
physics.
Darcy Horrocks: Eh? Pish and, indeed,
tosh! As a gentleman, I must take issue with
your bald assertion. Shape can affect taste
(ask any sommelier or anyone who's drunk
from glasses blown to match the wine) but
colour/transparency can only affect mood.
American coffee tastes watery because it's
brewed that way: find an Italian deli and ask
for a Ristretto(ree-STRAY-toh): same coffee,
incredible flavour. Or worse, go to Italy.
But be prepared never to be able to drink
Starbucks again! (This email to be taken terribly
terribly seriously indeed.)
Robert G. Doucette: Regarding your
observation on the physics of coffee served
in glass cups: HUH? It has been a few years since
I spent my days as an active physicist, but I
don't recall how the optical properties of
the coffee cup affects the taste of the coffee.
Now, there may be some chemistry involved, certainly
some psychology, but probably not physics. On the
other hand, the material of the coffee cup could
affect the thermodynamics of the coffee. Ceramics
are better insulators than glass. The temperature
of the coffee and the texture of the mug would be
different than expected. So the total experience
of the coffee may be different.
Bill Nagler: If coffee tastes watery
in a glass mug because light passing through the
mug pushes the coffee molecules apart, why does
coffee taste better in a white mug than in a black
one? Theoretically, a white mug will keep the
coffee molecules farther apart than a black mug.
Or is it that the coffee molecules are held too
close together in a black mug? Or does the color of
the mug significantly effect [sic] the epithelium
of the lips and tongue?
Joe Robinson: The best coffee is served in
Latin American countries. And it's not the
type of coffee, but the way it is prepared and
served. When I was in Honduras on business last
year, the waiter would come around with two stainless
steel pitchers (no, not regular and decaf!). He would
first ask "cafe?", at which time he would
fill your cup half way with a really strong, dark
brew from one pitcher. Then he would ask "con
leche?", and if you said "si" he would
fill the rest of your cup with hot milk from the
other pitcher. Very few people drink the coffee
black. In Panama, coffee is prepared and served in
a similar fashion. I haven't had a good cup of
coffee since I've been back in the States!
Christina O'Sullivan: That paragraph on
Strong Coffee was a "Eureka." You know,
the Sad Thing is that I live in Seattle, and with
hundreds of espresso joints abound, you would THINK
some of the better places in town would know better.
The very very best place in Seattle does use white
opaque mugs. The place I frequent has glass mugs,
but I take my mochas to go by and large.
Charlie McDannald: Amen! I thought it was
just me, but even Starbucks (who should know better)
at most Barnes & Noble stores does this. Also,
the coffee should be in a short, wide mug, rather
than a tall drink glass.
Thanks, one and all.
