drinking coffee is one of life's
pleasures
a pleasure that cannot be duplicated by
any other
[Music]
welcome to this episode of weird coffee
science and today we're going to be
messing around and having some fun with
the buffer to explain this I'm gonna
have to talk to you about water
chemistry in relation to coffee brewing
and lots of you are hoping that this is
going to be that video the one that
explains everything the one that says
which is the right sort of water
chemistry for the best-tasting coffee
this is not that video I am going to
talk to you about a couple of key
aspects of water chemistry though but
before we begin I do need to shout out
it's got rayou this is ultimately his
idea he mentioned this this kind of big
idea to me
when he was in London and it's nagged at
the back of my brain and I wanted to try
it I thought this was the perfect
opportunity
so let's talk water chemistry and I'm
gonna do it in a way that I hope is
simple enough that if you don't care
that much it still makes sense and if
you do care you don't feel like I'm
basically lying to you now for a long
time we talked about TDs in water and
that's total dissolved solids and if you
look at say the back of a bottle of
mineral water you'll be able to see what
kind of minerals are dissolved in that
water now TDS is easy to measure you can
buy a cheap TDS meter it'll tell you how
much stuff is in the water
and we used that for a long time to kind
of tune our recipes and tune our water
treatment but people like Max walk alone
our dash would pretty vocal in saying
TDS is kind of useless it tells you that
there's lots of stuff in there but not
what makes it up and really to massively
oversimplify there are two big
categories of things when it comes to
coffee that are important the first are
the minerals things like calcium things
like magnesium these are necessary to
help extract coffee flavor too much can
be bad but not enough can be bad as well
with calcium and magnesium they each get
involved in slightly different reactions
so having a load of calcium will produce
a brew that tastes quite different to
having a load of magnesium we're not
going to get too deep into that today
the other key aspect of water chemistry
is what's called the buffer the
alkalinity of the water
buffering compounds when they go into
solution produce both a weak acid and a
weak base in that solution right so if
you add an acid to them that base reacts
with that acid and it neutralizes it
that way your pH doesn't move too much
you add an acid to a buffered solution
now things like your blood have a ton of
buffer in them because if the pH of your
blood moves much at all
you're dead that's very bad now in water
bicarbonate acts as the buffering have
compound here so you'll see a
correlation between the level of
bicarbonate and it's alkalinity it's
buffering potential if you took a filter
coffee and you had a ton of buffer in
that water
you'd mute out a lot of interesting
flavors it would be very boring now most
of the time we talk about brewing water
for coffee we're often talking about
filter coffee
now the strength of filter coffee is
usually between let's say 1.3 to 1.5%
that's how much of that coffee is is
dissolved coffee and the rest the 98.7
to the 98.5 that's just water filter
coffee is not particularly strong at all
now espresso well that has a much higher
concentration at that point you're
looking at maybe 8 through 10 even
twelve percent strength Scott's
suggestion was what if the amount of
buffer correlated to the strength of the
beverage right having the right amount
of buffer for filter coffee well that
might not be the right amount of buffer
for espresso what if you had let's say
seven times more buffer in your espresso
what would happen would that moderate
the acidity of a super light roast a
kind of filter coffee roast that when
you brew it as espresso is just brutally
dominantly unpleasantly acidic so what
we're gonna do is this we're gonna take
a coffee we're gonna take a Kenyan
coffee that was roasted for filtered
drinking we're gonna make some espresso
with it that's gonna be our benchmark
because we can extract that but that end
result as an espresso may not taste that
good let's start by getting an espresso
machine
let's start by dialing it in with just
some nice brewing water and pulling
shots of this light roast to filter
roast kind of coffee and seeing how that
tastes
we're gonna do here to start off with is
take some these mean normal brewing
water it's relatively low in both
minerals and actually relatively low in
buffer but that's okay because I
actually want a benchmark of what will
be a very acidic espresso I'm gonna dose
20 grams into this machine
I'm gonna pull 40 grams out in around 28
30 seconds there should be a lot a lot
of acidity in the cup which is what we
want for this experiment I need some
espresso we've got the all-important
teaspoon we can give this espresso a
little stir that's got a lot of acidity
that's got a lot of acidity in it this
is exactly what I wanted to explore this
is a great benchmark so this you yoo-hoo
there's a ton of origin characteristics
here I can taste the coffee that went in
there there is a ton of sweetness in
this but my oh my this is sour so Wow
on to our first experiment so what I've
done and you just have to trust me on
this because I can't actually prove it
to you is I've changed the water inside
this this machines tank and we've gone
to a very high alkalinity water it's
like 350 milligrams per liter alkalinity
which is about seven times more than you
would have in say good brewing water the
question is if you're going at much
higher concentrations if the
concentration of espresso is seven times
higher than that a filter ish does the
seven times higher alkalinity give you
balance wherein you would usually
struggle there's only one way to find
out we have to make more delicious
espresso so same thing twenty grams of
coffee in 40-ish grams of coffee out and
around about thirty seconds that's our
benchmark let's make it happen
looks good
acids definitely there but it doesn't
hurt my face still maybe a touch more
acid that I might want a little harsh
bad about better than before no no
physical pain as before now that's
definitely interesting but there is one
big problem high levels of bicarbonate
coupled with at reasonably high levels
and minerals coupled with a hot
environment equals limescale so this
kind of water is much much much more
likely to scale up a machine and cause
you problems at this point there's
something interesting here but I'm not
sure I'd recommend brewing with high
alkalinity water there is one more idea
to discuss but before we do that I just
need to tell you about this video
sponsor which is Squarespace from
websites and online stores to marketing
tools and analytics Squarespace is the
all-in-one platform to build a beautiful
online presence and to run your business
if you want all the information
contained in today's video then there's
a link to my website down below and
that's a website that I built with
Squarespace
it was so quick and it was so easy to do
I could create something beautiful but
something unique something that was mine
I could take one of their myriad of
templates and customize it very simply
beyond that I don't have to worry about
patching or installing upgrades it's all
taken care of and if I do have an issue
there's 24/7 email support that really
matters to me
now someone active across a number of
social media sites I love the way that
Squarespace interacts with them it makes
it super easy to import content from
places like Instagram or Twitter but at
the same time I can simultaneously
publish back to those platforms it makes
it a super easy hub for my work so why
not head to Squarespace comm and sign up
for a free trial build a website and
when you're ready to launch go to
Squarespace comm slash James Hoffman or
use James Hoffman as a discount code to
get 10% off your first website or domain
name
thanks so much to Squarespace for
sponsoring this video
now I did have a second experiment in
mind what I wanted to do was brew that
original that kind of benchmark espresso
but add the alkalinity in afterwards you
see alkalinity is going to affect the
extract of coffee right it's going to
affect the liquid is going to affect the
pH of that liquid it can affect it if
you add it into the Machine but there's
no real reason that you couldn't just
add it into the cup and still have that
buffering effect on the acidity of the
cup now you're gonna need a lot more
bicarb here like a lot more so I've made
up a solution just using sodium
bicarbonate so this is 2,000 milligrams
per liter of alkalinity that's a lot so
what we should be able to do is just add
maybe 5 grams of that water slightly
dilute our espresso but then add a bunch
of buffer to that drink to see if it
kind of mops up some acidity so what
we're going to need to do of course is
to brew another espresso give it a
little taste just to give myself a
benchmark yeah yeah yep that's still
it's still very sour so I have my super
high alkalinity water here but I'm gonna
add maybe 5 grams so does this work yes
yes it does there's still tons of acid
here like this was still an overwhelming
level of acidity in the coffee that the
buffer 5 grams of this buffer isn't
going to kind of mop it all up but
goodness mean that's an interesting
change now I'm trying to work out if
it's in other ways changing or messing
with my perception of the coffee I feel
like there's been a textural change here
yeah I know we need to do this
double-blind and there's some flaws here
but there's no question that that has
changed the experience of this coffee it
is more enjoyable to drink I don't know
what this means I know that coffee
science is weird
I think we've got something kind of cool
here I think we've got something really
fun and definitely something that you at
home can play with get some some
bicarbonate of soda and it's important
that you get bicarbonate of soda don't
get baking powder that has other stuff
you want bicarbonate of soda sodium
bicarbonate that's what you want it's
cheap it's everywhere it's in every
grocery store get some you probably have
some already dissolve it in water I used
about 3.2 grams per liter to produce
water that had about 2,000 milligrams
per liter of alkalinity now you could
probably double that actually and be
able to then use less in your espresso
but this is so easy to do and I think
you should totally do it the potential
is kind of interesting here I'd be
really interested to hear if you don't
like this the point here is that you
could have like a little dropper bottle
of water that has super high alkalinity
and if you pull a shot that's well
extracted but just a little bit too
acidic one drop two drops three drops a
gram two grams
maybe that rounds it out maybe that
cleanse it up maybe you don't lose any
origin characteristics maybe you keep
everything you like you know
historically we used sugar to fix
acidity right if you take lemon juice if
you add sugar to it it becomes Pleasant
the pH doesn't change but the perceived
acidity does here we're messing with the
pH and it changes the kind of acidity in
a different way than sugar does right
but it doesn't skew things it doesn't
obscure things in the same way it's
super interesting I want you to try it
and tell me why this is a bad idea tell
me why this is stupid tell me why this
is wrong tell me if it just makes you
feel weird adding a little bit of bicarb
of soda to your espresso I think with
lots of coffees it won't work right like
this is for light roasted coffees that
taste really good but are just too
acidic when you breathe them as espresso
where that concentration is just
overwhelming I would love love to hear
your thoughts if you try this thank you
so much for watching I hope you have a
great day
pleasures
a pleasure that cannot be duplicated by
any other
[Music]
welcome to this episode of weird coffee
science and today we're going to be
messing around and having some fun with
the buffer to explain this I'm gonna
have to talk to you about water
chemistry in relation to coffee brewing
and lots of you are hoping that this is
going to be that video the one that
explains everything the one that says
which is the right sort of water
chemistry for the best-tasting coffee
this is not that video I am going to
talk to you about a couple of key
aspects of water chemistry though but
before we begin I do need to shout out
it's got rayou this is ultimately his
idea he mentioned this this kind of big
idea to me
when he was in London and it's nagged at
the back of my brain and I wanted to try
it I thought this was the perfect
opportunity
so let's talk water chemistry and I'm
gonna do it in a way that I hope is
simple enough that if you don't care
that much it still makes sense and if
you do care you don't feel like I'm
basically lying to you now for a long
time we talked about TDs in water and
that's total dissolved solids and if you
look at say the back of a bottle of
mineral water you'll be able to see what
kind of minerals are dissolved in that
water now TDS is easy to measure you can
buy a cheap TDS meter it'll tell you how
much stuff is in the water
and we used that for a long time to kind
of tune our recipes and tune our water
treatment but people like Max walk alone
our dash would pretty vocal in saying
TDS is kind of useless it tells you that
there's lots of stuff in there but not
what makes it up and really to massively
oversimplify there are two big
categories of things when it comes to
coffee that are important the first are
the minerals things like calcium things
like magnesium these are necessary to
help extract coffee flavor too much can
be bad but not enough can be bad as well
with calcium and magnesium they each get
involved in slightly different reactions
so having a load of calcium will produce
a brew that tastes quite different to
having a load of magnesium we're not
going to get too deep into that today
the other key aspect of water chemistry
is what's called the buffer the
alkalinity of the water
buffering compounds when they go into
solution produce both a weak acid and a
weak base in that solution right so if
you add an acid to them that base reacts
with that acid and it neutralizes it
that way your pH doesn't move too much
you add an acid to a buffered solution
now things like your blood have a ton of
buffer in them because if the pH of your
blood moves much at all
you're dead that's very bad now in water
bicarbonate acts as the buffering have
compound here so you'll see a
correlation between the level of
bicarbonate and it's alkalinity it's
buffering potential if you took a filter
coffee and you had a ton of buffer in
that water
you'd mute out a lot of interesting
flavors it would be very boring now most
of the time we talk about brewing water
for coffee we're often talking about
filter coffee
now the strength of filter coffee is
usually between let's say 1.3 to 1.5%
that's how much of that coffee is is
dissolved coffee and the rest the 98.7
to the 98.5 that's just water filter
coffee is not particularly strong at all
now espresso well that has a much higher
concentration at that point you're
looking at maybe 8 through 10 even
twelve percent strength Scott's
suggestion was what if the amount of
buffer correlated to the strength of the
beverage right having the right amount
of buffer for filter coffee well that
might not be the right amount of buffer
for espresso what if you had let's say
seven times more buffer in your espresso
what would happen would that moderate
the acidity of a super light roast a
kind of filter coffee roast that when
you brew it as espresso is just brutally
dominantly unpleasantly acidic so what
we're gonna do is this we're gonna take
a coffee we're gonna take a Kenyan
coffee that was roasted for filtered
drinking we're gonna make some espresso
with it that's gonna be our benchmark
because we can extract that but that end
result as an espresso may not taste that
good let's start by getting an espresso
machine
let's start by dialing it in with just
some nice brewing water and pulling
shots of this light roast to filter
roast kind of coffee and seeing how that
tastes
we're gonna do here to start off with is
take some these mean normal brewing
water it's relatively low in both
minerals and actually relatively low in
buffer but that's okay because I
actually want a benchmark of what will
be a very acidic espresso I'm gonna dose
20 grams into this machine
I'm gonna pull 40 grams out in around 28
30 seconds there should be a lot a lot
of acidity in the cup which is what we
want for this experiment I need some
espresso we've got the all-important
teaspoon we can give this espresso a
little stir that's got a lot of acidity
that's got a lot of acidity in it this
is exactly what I wanted to explore this
is a great benchmark so this you yoo-hoo
there's a ton of origin characteristics
here I can taste the coffee that went in
there there is a ton of sweetness in
this but my oh my this is sour so Wow
on to our first experiment so what I've
done and you just have to trust me on
this because I can't actually prove it
to you is I've changed the water inside
this this machines tank and we've gone
to a very high alkalinity water it's
like 350 milligrams per liter alkalinity
which is about seven times more than you
would have in say good brewing water the
question is if you're going at much
higher concentrations if the
concentration of espresso is seven times
higher than that a filter ish does the
seven times higher alkalinity give you
balance wherein you would usually
struggle there's only one way to find
out we have to make more delicious
espresso so same thing twenty grams of
coffee in 40-ish grams of coffee out and
around about thirty seconds that's our
benchmark let's make it happen
looks good
acids definitely there but it doesn't
hurt my face still maybe a touch more
acid that I might want a little harsh
bad about better than before no no
physical pain as before now that's
definitely interesting but there is one
big problem high levels of bicarbonate
coupled with at reasonably high levels
and minerals coupled with a hot
environment equals limescale so this
kind of water is much much much more
likely to scale up a machine and cause
you problems at this point there's
something interesting here but I'm not
sure I'd recommend brewing with high
alkalinity water there is one more idea
to discuss but before we do that I just
need to tell you about this video
sponsor which is Squarespace from
websites and online stores to marketing
tools and analytics Squarespace is the
all-in-one platform to build a beautiful
online presence and to run your business
if you want all the information
contained in today's video then there's
a link to my website down below and
that's a website that I built with
Squarespace
it was so quick and it was so easy to do
I could create something beautiful but
something unique something that was mine
I could take one of their myriad of
templates and customize it very simply
beyond that I don't have to worry about
patching or installing upgrades it's all
taken care of and if I do have an issue
there's 24/7 email support that really
matters to me
now someone active across a number of
social media sites I love the way that
Squarespace interacts with them it makes
it super easy to import content from
places like Instagram or Twitter but at
the same time I can simultaneously
publish back to those platforms it makes
it a super easy hub for my work so why
not head to Squarespace comm and sign up
for a free trial build a website and
when you're ready to launch go to
Squarespace comm slash James Hoffman or
use James Hoffman as a discount code to
get 10% off your first website or domain
name
thanks so much to Squarespace for
sponsoring this video
now I did have a second experiment in
mind what I wanted to do was brew that
original that kind of benchmark espresso
but add the alkalinity in afterwards you
see alkalinity is going to affect the
extract of coffee right it's going to
affect the liquid is going to affect the
pH of that liquid it can affect it if
you add it into the Machine but there's
no real reason that you couldn't just
add it into the cup and still have that
buffering effect on the acidity of the
cup now you're gonna need a lot more
bicarb here like a lot more so I've made
up a solution just using sodium
bicarbonate so this is 2,000 milligrams
per liter of alkalinity that's a lot so
what we should be able to do is just add
maybe 5 grams of that water slightly
dilute our espresso but then add a bunch
of buffer to that drink to see if it
kind of mops up some acidity so what
we're going to need to do of course is
to brew another espresso give it a
little taste just to give myself a
benchmark yeah yeah yep that's still
it's still very sour so I have my super
high alkalinity water here but I'm gonna
add maybe 5 grams so does this work yes
yes it does there's still tons of acid
here like this was still an overwhelming
level of acidity in the coffee that the
buffer 5 grams of this buffer isn't
going to kind of mop it all up but
goodness mean that's an interesting
change now I'm trying to work out if
it's in other ways changing or messing
with my perception of the coffee I feel
like there's been a textural change here
yeah I know we need to do this
double-blind and there's some flaws here
but there's no question that that has
changed the experience of this coffee it
is more enjoyable to drink I don't know
what this means I know that coffee
science is weird
I think we've got something kind of cool
here I think we've got something really
fun and definitely something that you at
home can play with get some some
bicarbonate of soda and it's important
that you get bicarbonate of soda don't
get baking powder that has other stuff
you want bicarbonate of soda sodium
bicarbonate that's what you want it's
cheap it's everywhere it's in every
grocery store get some you probably have
some already dissolve it in water I used
about 3.2 grams per liter to produce
water that had about 2,000 milligrams
per liter of alkalinity now you could
probably double that actually and be
able to then use less in your espresso
but this is so easy to do and I think
you should totally do it the potential
is kind of interesting here I'd be
really interested to hear if you don't
like this the point here is that you
could have like a little dropper bottle
of water that has super high alkalinity
and if you pull a shot that's well
extracted but just a little bit too
acidic one drop two drops three drops a
gram two grams
maybe that rounds it out maybe that
cleanse it up maybe you don't lose any
origin characteristics maybe you keep
everything you like you know
historically we used sugar to fix
acidity right if you take lemon juice if
you add sugar to it it becomes Pleasant
the pH doesn't change but the perceived
acidity does here we're messing with the
pH and it changes the kind of acidity in
a different way than sugar does right
but it doesn't skew things it doesn't
obscure things in the same way it's
super interesting I want you to try it
and tell me why this is a bad idea tell
me why this is stupid tell me why this
is wrong tell me if it just makes you
feel weird adding a little bit of bicarb
of soda to your espresso I think with
lots of coffees it won't work right like
this is for light roasted coffees that
taste really good but are just too
acidic when you breathe them as espresso
where that concentration is just
overwhelming I would love love to hear
your thoughts if you try this thank you
so much for watching I hope you have a
great day