Reverse Osmosis water = sour shots?

[James Cheim]

Just wondering if anyone uses reverse osmosis water for espresso. I am
pulling shots using a Rocky, PID Silvia with commercial PF and 'LM'
double/triple baskets. I've was consistently getting very good results with
distilled water but installed a reverse osmosis (RO) system last year and
switched over to RO water. Since then I was never able to get a good shot.
Extraction time, texture, color and crema were all bang on but no matter how
I tweaked the PID, changed my grind/tamp and tried various beans (many of
which I earlier considered to be 'tried and true') I always got sour shots.
Really sour in that it was never drinkable straight up and at best was
mildly noticeable in a latte. I was very reluctant to think it was the water
because it tasted great from the tap and I tested it to have negligibly low
mineral content. I thoroughly cleaned and backflushed the machine but the
sourness persisted. Hot water run through the portafilter with no coffee
tasted fine, with no odour or sourness... it just makes sour coffee!

Does anyone have similar experiences or have an explanation for this? I
recall reading somewhere that reverse osmosis water is not totally
pH-neutral - could that be affecting the taste of the coffee? Right now I am
back to distilled water and everything was as it used to be. The sourness
totally went away the moment I put in distilled water, and I am now back
where I started - great coffee, but breaking my back hauling around those
18L water bottles.

Regards,
James

[David Lewis]

Post by James Cheim
Just wondering if anyone uses reverse osmosis water for espresso. I am
pulling shots using a Rocky, PID Silvia with commercial PF and 'LM'
double/triple baskets. I've was consistently getting very good results with
distilled water but installed a reverse osmosis (RO) system last year and
switched over to RO water. Since then I was never able to get a good shot.
Extraction time, texture, color and crema were all bang on but no matter how
I tweaked the PID, changed my grind/tamp and tried various beans (many of
which I earlier considered to be 'tried and true') I always got sour shots.
Really sour in that it was never drinkable straight up and at best was
mildly noticeable in a latte. I was very reluctant to think it was the water
because it tasted great from the tap and I tested it to have negligibly low
mineral content. I thoroughly cleaned and backflushed the machine but the
sourness persisted. Hot water run through the portafilter with no coffee
tasted fine, with no odour or sourness... it just makes sour coffee!

RO water by itself isn't very good for coffee; neither, by the way, is
distilled. The easiest solution for an RO system is to put an inline
calcite filter after it to add back a couple of grains of hardness. I
think Chris Coffee sells one that goes into a housing, and Omnipure
K5648 is a fairly widely available 10" inline one. Hope this helps.

Best,
David

[Marshall]

Post by David Lewis

Post by James Cheim
Just wondering if anyone uses reverse osmosis water for espresso. I am
pulling shots using a Rocky, PID Silvia with commercial PF and 'LM'
double/triple baskets. I've was consistently getting very good results with
distilled water but installed a reverse osmosis (RO) system last year and
switched over to RO water. Since then I was never able to get a good shot.
Extraction time, texture, color and crema were all bang on but no matter how
I tweaked the PID, changed my grind/tamp and tried various beans (many of
which I earlier considered to be 'tried and true') I always got sour shots.
Really sour in that it was never drinkable straight up and at best was
mildly noticeable in a latte. I was very reluctant to think it was the water
because it tasted great from the tap and I tested it to have negligibly low
mineral content. I thoroughly cleaned and backflushed the machine but the
sourness persisted. Hot water run through the portafilter with no coffee
tasted fine, with no odour or sourness... it just makes sour coffee!

RO water by itself isn't very good for coffee; neither, by the way, is
distilled. The easiest solution for an RO system is to put an inline
calcite filter after it to add back a couple of grains of hardness. I
think Chris Coffee sells one that goes into a housing, and Omnipure
K5648 is a fairly widely available 10" inline one. Hope this helps.
Best,
David

Ditto. There's a lot of interesting chemistry going on in a cup while
it's brewing. Minerals don't just add flavor by themselves. They bond
with important flavor elements in the coffee grounds. Assuming you're
starting with good beans, without minerals, you are leaving lots of
good flavor behind. A blind comparison of coffees brewed with water at
different mineral levels is pretty persuasive for most people. Reams
have been on the subject.

Some places to start:
http://www.scaa.org/whatis_brewing.asp
http://www.gourmetretailer.com/gourmetretailer/magazine/article_display.jsp?vnu_content_id=2071600

Marshall

[Dan Bollinger]

Post by James Cheim
Does anyone have similar experiences or have an explanation for this?

Both RO and distilled water is acidic and not good for the cup nor the
machine. If your 'distilled' water tastes better, then I think it isn't all
that distilled. I added a calcite reformulator to mine. (some people call
them 'filters' but of course that's the wrong terminology. A calcite filter
would remove, not add, calcite) Dan

[~ ElektraMan ~]

Dan,

Post by Dan Bollinger
Both RO and distilled water is acidic and not good for the cup nor the
machine.

RO, distilled water acidic? What damage do they do to the machines?

Thanks,
Steve

Post by Dan Bollinger

Post by James Cheim
Does anyone have similar experiences or have an explanation for this?

If your 'distilled' water tastes better, then I think it isn't all

Post by Dan Bollinger
that distilled. I added a calcite reformulator to mine. (some people call
them 'filters' but of course that's the wrong terminology. A calcite filter
would remove, not add, calcite) Dan

[Randy R]

Post by ~ ElektraMan ~
Dan,

Post by Dan Bollinger
Both RO and distilled water is acidic and not good for the cup nor the
machine.

RO, distilled water acidic? What damage do they do to the machines?
Thanks,
Steve

Because the (RO or distilled,) water is low in minerals, it is very acidic
(low PH,) and will corrode any metal it comes in contact with because it
will leech out the minerals because the TDS (total dissolved solids,) is too
low. The calcite will replace the missing minerals and make the water
neutral, as long as the water stays in contact with the calcite for long
enough.
Hard water has a high PH and high TDS and when it is heated it looses
minerals in the form of scale, especially when the water is alkaline.

This relates to how coffee is brewed. The ideal water for brewing has a
neutral PH and a TDS between 100 and 200. If the TDS is too low, the water
will leech out too much solubles out of the coffee making it "muddy". If the
TDS is too high, the coffee will be under extracted and bitter. This is the
same for brewed coffee and espresso.

Randy R

[Dan Bollinger]

Post by Randy R

Post by ~ ElektraMan ~
RO, distilled water acidic? What damage do they do to the machines?
Thanks,
Steve

Because the (RO or distilled,) water is low in minerals, it is very acidic
Randy R

Steve, Don't be alarmed, Randy is exaggerating when he says "very acidic."
Its not like you can strip chrome with RO water or even make salad dressing
from it. Mine tests at 6.2 pH. Neutral is 7.0. I now have a calcite
reformulator between the RO unit and my plumbed IM. When I was using it as
a pourover machine I treated the water by adding calcite to a pitcher and
giving it a good shake before pouring into the reservoir. Write to me
offline if you want more information. Dan

[Randy R]

Post by Dan Bollinger
Steve, Don't be alarmed, Randy is exaggerating when he says "very acidic."

Sorry, I didn't mean to say "very acidic". I should have said (and what I
meant to infer,) was that water that has a PH that is lower than neutral
will have more of an effect on taste than it will on the espresso machine
boiler and fittings, though it may have some effect over the long term if
you continued to use pure RO or distilled water.

Randy R

[Dimal]

Hi,

Here's a very brief explanation of why distilled/RO water may be acidic.
We're not talking about highly corrosive solutions here as the
concentrations involved are extremely low due to significant dilution. Other
factors within the system(s) containing the water are able to affect pH far
more than the very small quantities of ions present in the original
distilled water. Anyway, this article and lots of others explain the causes
and effects.

Cheers,
Dimal.
(Please remove the alpha "at" from my address to reply)

Post by Randy R

Post by ~ ElektraMan ~
Dan,

Post by Dan Bollinger
Both RO and distilled water is acidic and not good for the cup nor the
machine.

RO, distilled water acidic? What damage do they do to the machines?
Thanks,
Steve

Because the (RO or distilled,) water is low in minerals, it is very acidic
(low PH,) and will corrode any metal it comes in contact with because it
will leech out the minerals because the TDS (total dissolved solids,) is too
low. The calcite will replace the missing minerals and make the water
neutral, as long as the water stays in contact with the calcite for long
enough.
Hard water has a high PH and high TDS and when it is heated it looses
minerals in the form of scale, especially when the water is alkaline.
This relates to how coffee is brewed. The ideal water for brewing has a
neutral PH and a TDS between 100 and 200. If the TDS is too low, the water
will leech out too much solubles out of the coffee making it "muddy". If the
TDS is too high, the coffee will be under extracted and bitter. This is the
same for brewed coffee and espresso.
Randy R

[Dimal]

Hi again,

After all that I omitted to paste the link to the info page I was referring
to. Sorry about that but here it is, guaranteed this time...
http://antoine.frostburg.edu/chem/senese/101/matter/faq/is-distilled-water-a-solution.shtml

Cheers,
Dimal.
~~~~~~~~~~~~~~~~~~ Message Break ~~~~~~~~~~~~~~~~~~

Post by Dimal
Hi,
Here's a very brief explanation of why distilled/RO water may be acidic.
We're not talking about highly corrosive solutions here as the
concentrations involved are extremely low due to significant dilution. Other
factors within the system(s) containing the water are able to affect pH far
more than the very small quantities of ions present in the original
distilled water. Anyway, this article and lots of others explain the causes
and effects.
Cheers,
Dimal.
(Please remove the alpha "at" from my address to reply)

Post by Randy R

Post by ~ ElektraMan ~
Dan,

Post by Dan Bollinger
Both RO and distilled water is acidic and not good for the cup nor the
machine.

RO, distilled water acidic? What damage do they do to the machines?
Thanks,
Steve

Because the (RO or distilled,) water is low in minerals, it is very acidic
(low PH,) and will corrode any metal it comes in contact with because it
will leech out the minerals because the TDS (total dissolved solids,) is

too

Post by Randy R
low. The calcite will replace the missing minerals and make the water
neutral, as long as the water stays in contact with the calcite for long
enough.
Hard water has a high PH and high TDS and when it is heated it looses
minerals in the form of scale, especially when the water is alkaline.
This relates to how coffee is brewed. The ideal water for brewing has a
neutral PH and a TDS between 100 and 200. If the TDS is too low, the water
will leech out too much solubles out of the coffee making it "muddy". If

the

Post by Randy R
TDS is too high, the coffee will be under extracted and bitter. This is

the

Post by Randy R
same for brewed coffee and espresso.
Randy R

[vMike]

Post by ~ ElektraMan ~
Dan,

Post by Dan Bollinger
Both RO and distilled water is acidic and not good for the cup nor the
machine.

RO, distilled water acidic? What damage do they do to the machines?
Thanks,
Steve

Post by Dan Bollinger

Post by James Cheim
Does anyone have similar experiences or have an explanation for this?

If your 'distilled' water tastes better, then I think it isn't all

Post by Dan Bollinger
that distilled. I added a calcite reformulator to mine. (some people

call

Post by Dan Bollinger
them 'filters' but of course that's the wrong terminology. A calcite

filter

Post by Dan Bollinger
would remove, not add, calcite) Dan

I think that RO water is not good for the autofill. Not enough TDS. I think
there was a post a while back on that discussion. RO water was blamed for
taken out a Giotto, I believe.
Mike