Francisco Mena at Exclusive Coffees in Costa Rica |
- Chris | follow on twitter @Gastronomin and this blog for continued updates on this years harvest.
Canonical, Coffee Education and Tech Tips: Practical tips and advice to give you the tools to brew better coffee. Brought to you by Pete Cannon, who handles barismo's in house training, education, and technical services.
We’re back to water quality again, to finally talk
about how to filter it for coffee brewing. See Part 1 for the basics of
water chemistry, and Part 2 for how our water tests in the Boston area.
The numbers for what’s ideal for brewing vary slightly based on who you ask. The SCAA water specification is available here. La Marzocco has a more specific set of water specifications for what is best for the health of espresso machines at this link.
We
have some variation from these numbers in the Boston area — our water
is relatively soft (very low hardness), but you can still brew great
coffee with it. In Boston, our pH is slightly alkaline; in Cambridge,
occasionally the pH swings higher, but alkalinity stays roughly the
same. Tangentially, we’ve noticed a decrease in brewed coffee quality
when pH increases towards 9.0.
In
Boston, the only major concern for water quality are chemical
impurities: things in our water that give off tastes. The most familiar
of these is chlorine, but there can also be localized plumbing issues
that will contribute to this. The good news is that this is easy to take
care of with a simple carbon & particulate filter. For in-line
filtering, something like this.
For home use, there are a number of common countertop water filtration
devices (e.g. Brita) that provide basic carbon filtration.
In
Cambridge, for home use a basic carbon filter will work fine for
brewing filter coffee. However, for commercial applications, there are
some additional concerns due to chlorides. Historically, Cambridge has
experienced intermittently high chloride levels at times, due to runoff
from road de-icing chemicals. High chloride levels cause metals to
corrode — with espresso machines being particularly vulnerable.
For
commercial usage, it’s critical to test your water regularly. Water
quality fluctuates seasonally, so a test at one point of the year will
not always be representative for the rest of the year. If chloride
contamination rises to unacceptable levels (>30 ppm), reverse osmosis
is the only way to treat that water. You will need to design an
appropriate remineralization system to restore some minerals to that
water afterwards. RO is expensive, but it sure is less expensive than
buying a new espresso machine!
- Pete Cannon | barismo's training, education and technical services. Follow his updates here on the barismo blog.Stay Fresh Updates: Upcoming events, classes and education, new coffees, and much more... Sign up to receive updates.
Saturday, March 22, 2014 from 9:30am-2pm
barismo at the Somerville Winter Farmers Market
Grab a freshly roasted retail bag of barismo coffee from our well stocked weekly selection, as well as a fresh, made-to-order pourover or a delicious cup of cold brew iced coffee. Catch us soon, only two markets left! And then where will you go for fresh roaster coffee in Somerville? Stay Tuned for updates on our new location...
Sunday, April 6, 2014 from 5pm-7pm
Espresso 101 class hosted at barsimo
"A barista will explain grinding, tamping, and more, then watch as you pull shot after shot. Like an espresso coach, he’ll give you pointers on everything from your mouse tails to your brew’s hue. Small classes are taught monthly on Sunday nights" - from a recent Boston Globe article featuring barismo's Espresso 101 class. (And then there was this endorsement.) One seat left as of posting, sign up Now!