How SP3 adds tastes to your Coffee!
Watch Your Coffee!
If Calcium and Magnesium are
put into the Coffee
- “it changes the Coffee”
Helping Coffee flow smoothly
Chemistry of taste
with Ca2+ & Mg2+
Top ten sources of antioxidants in diets
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Coffee
Chemistry
Water
Technology
& Chemicals
Coffee
WATCH WATER®
Chemistry
The Science behind the perfect coffee – it’s in the water!
08 June 2014 (weblink)
page
2
Coffee
Chemistry
A chemist at the University has teamed up with
the UK Barista Champion to find the best type of
water for making coffee. The pair are heading to
the World Barista Championships in Italy on 8
June to share their coffee chemistry knowledge
with the rest of the world.
Christopher Hendon, a PhD student from our
Department of Chemistry, embarked on the
project in his spare time with friend Maxwell
Colonna-Dashwood, owner of Colonna and
Small’s coffee shop in Bath, after a discussion
about why the taste of coffee varies so much.
Hendon used computational chemistry methods
to look at how different compositions of water
affect the extraction of six chemicals that
contribute to the flavor of coffee, along with
caffeine. The study, published in the Journal of
Agricultural Food Chemistry, found that water
composition can make a dramatic difference to
the taste of coffee made from the same bean.
Hendon explained: “Coffee beans contain hundreds
of chemicals; the precise composition depends on
the type of bean and how it is roasted. The flavor
of the resulting coffee is determined by how much
of these chemicals are extracted by the water,
which is influenced by roast time, grind,
temperature, pressure and brew time.
“We’ve found that the water composition is key
to the proportions of sugars, starches, bases
and acids extracted from a particular roast.”
The coffee industry uses guidelines on the ideal
water for coffee extraction from the Speciality
Coffee Association of Europe (SCAE), which
measures ionic conductivity to quantify the total
dissolved solids, however the researchers found
that it was the proportions of these ions that
affected the extraction and therefore the taste of
the coffee.
Hendon explained: “Hard water is generally
considered to be bad for coffee, but we found it
was the type of hardness that mattered – while
high bicarbonate levels are bad, high magnesium
ion levels increase the extraction of coffee into
water and improve the taste.”
The study also found that sodium rich water, such
as that produced by water softeners, didn’t help
the taste of the coffee either.
Hendon added: “There is no one particular perfect
composition of water that produces consistently
flavorsome extractions from all roasted coffee.
But magnesium-rich water is better at extracting
coffee compounds and the resultant flavor
depends on the balance between both the ions in
the water and the quantity of bicarbonate
present.”
Maxwell Colonna-Dashwood, co-author on the
paper, said: “Unfortunately most of the time you
are limited by the source water available. Water
from the tap varies regionally and from day to day
depending on how much it rains – the only way you
can get consistent quality is to use bottled
water, but even then not all waters are the same.
“For the Championships we test the local water
and then select the roast that is most suitable
for that particular water. For example you could
use a heavy roast with a soft water as it doesn’t
extract very much, but with hard water it would
extract too much and give a bitter taste, so it
would be better to use a lighter roast.
“Traditionally the coffee making industry is most
concerned about using water that doesn’t scale
up their machines. But we argue that more value
should be placed on the flavor of the coffee and
want to use chemistry to help people make the
best coffee they can with the water they have
available.”
Maxwell Colonna-Dashwood won the UK Barista
Championship in April and will represent the UK at
the World Championships in Rimini, Italy from 9
June.
The competition takes place over four days, with
baristas from 50 countries vying to become
World Barista Champion. Each competitor must
prepare four espressos, four cappuccinos, and
four original signature drinks to exacting
standards in a 15-minute performance set to
music. Each entry is judged on the taste of
beverages
served,
cleanliness,
creativity,
technical skill, and overall presentation.
Hendon and Colonna-Dashwood are now planning
to share their knowledge on the science behind
making the perfect coffee in a book
www.watchwater.de
A
Coffee
mmonium
Chemistry
removal
Water
Technology
& Chemicals
Laboratory News - CHEMISTRY IN THE PERFECT COFFEE
18 March 2015 (weblink)
So is the taste of coffee really affected
by water?
H2O
Most people are familiar with very small
quantities
of
chemicals
having
catastrophic
effects
on
chemical
reactions. Generally speaking, minute
H+
OH- Hydroxide
quantities of anything in a bulk
substance are termed impurities. Water
CO2
is no different, in bulk water acts like
Carbon
dioxide
H2O, but if we look closely, all water
contains ions (even water itself autoHCO3 Bicarbonate
ionises to form H+ and OH-, this defines
the pH scale). But depending on where
you are from, and what’s in the ground,
H2CO3 Carbonic acid
and how much rain you’ve had, and how
rich in CO2 the atmosphere is and many
Positive ions Ca2+, Mg2+ → CaCO3
more variables, we find that there are
low levels of Ca2+, Mg2+ and other less
when dissolves in water
pleasant things like UO22+. These
becomes Temporary Hardness = Ca(HCO3)2
positive ions can be considered flavor
All the positive ions are bounded to HCO3-(bicarbonate)
claws. They grab onto molecules in the
Which originally came from CO2 (carbon dioxide)
coffee bean and pull them into the
water. However, if you extract for too
FILTERSORB® SP3 opens this bracket
long, they start to pull out heavier
compounds, which are generally cellular
Ca(HCO3)2 → CaCO3 + H2O + CO2 ↑
(pure)
(g)
breakdown products, and they taste
page
bitter. If the extraction is too short, the
2+
Ca2+ +
coffee only has lightweight compound in
(flavor)
the water. All this positive charge has
to be countered somehow, and the most
Glass (SiO2-) coated very
familiar
counter
ion
is
HCO3-,
strong Hydrophillic surface
bicarbonate, which originally came from
dissolved carbon dioxide. Bicarbonate is
amphiprotic: it is acidic and basic. It
Negative surface charge
exists in the highest concentration of
SP3
attracts the positive ions
any naturally occurring ions, and is also
Ca(HCO3)2
the most basic constituent in water Hard water molecule
besides the trace amounts of OH-. Its
Ca2+
positive
job is to stabilize pH, and it does so by
CaCO3
deprotonating acids, and this is a big
Source of
crystal
Ca2+ & Mg2+
problem. We hold a nice balanced acidity
2+
CO32as one of the most important flavors in
negative
coffee, and if there is too much
(flavor)
H+
bicarbonate we end up tasting the
conjugate bases of the coffee acids and
corrects the pH as CO2 leaves the water as gas at
they are bitter.
temperutre of 27°C – 32°C (80.6°F – 89.6°F)
Coffee
Chemistry
Mg
3
Mg
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