On 10/11/2019 09:41, Scott wrote:
On Sun, 10 Nov 2019 09:27:15 +0000, Martin Brown
wrote:

It makes an even bigger difference for coffees. It turns out that for
them to be optimally made requires exactly the right amount of hardness
or it tastes too bitter (excessive hardness) or insipid (too soft).

Water hardness critically affects the free alkaloids in the drink as
well as the insoluble calcium scum that forms on the top.

Interesting, do the big chains (Costa etc) try to supply a consistent
product?

I went to a lecture on the chemistry of coffee at Newcastle University
where unusually the audience were able to participate in a controlled
tasting starting with deionised water and working up in hardness. The
lecture was held in a bar since no eating or drinking is permitted in
lecture theatres. One chemist and one top barrista doing it.

Starbucks is notorious for burning the beans to an inch of their life
and making the tarry stuff up with deionised water. The taste is
characteristic and best suited to the rubbish thin US coffee.

Couldn't find the same diagram online but this one is close:
https://www.cirellicoffee.com.au/wp-...led_grande.jpg

Costa is somewhat less burnt. But yes reproducibility is viewed as a
brand strength (as is maximising the amount of coffee made per bean).

--
Regards,
Martin Brown