# different water - sour brews



## dsc (Jun 7, 2013)

Gents,

before the weekend I've received a package from SQM with 4 lovely coffees. Super excited I boiled some water and did a Clever brew using my standard method (described in the Clever thread), but the brew came out far from perfect. I changed the grind a bit, messed around with the brew time, but still there was a lot of bitterness which I wasn't happy with. Yesterday I decided to use some mineral water (the big 5L bottled type) instead of tap water to see if it makes a difference, but it went the other way, now all my brews are super sour, as if I used lemon on the brew itself. This is both with standard brewing temps (around 96degC brew water) and high brew temps (around 98degC).

Has anyone experienced anything similar? I was expecting to see less bitterness and more friendly flavours, but it seems like mineral water, or at least the type I'm using, isn't super coffee friendly. Could it be that the mineral water has too many solids already, so it's crap as brew water, not taking out all the lovely flavours / solids from the coffee?

Regards,

T.


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## garydyke1 (Mar 9, 2011)

Water certainly has an impact. Volvic is best mineral water Ive come across but it is expensive (wish they did 5 ltr bottles)

I use a 50:50 blend of Waitrose essential and Buxton, with 100% waitrose in the espresso machine. It tends to under-extract (sourish) versus brita filter severn trent (bitters) but it has the advantage of being a fixed variable - filter cartridges degrade etc, and, no chlorine/floride.

Makes me wonder how many roasters (who cup using THEIR local water) are coming across as 'always sour' or 'always bitter' to certain folk across other parts of the country


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## matisse (Jul 21, 2010)

Sounds like massive under extraction to me, but which coffees are they?

which water did you use? ashbeck spring from tesco seems to be the best for filter.


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## garydyke1 (Mar 9, 2011)

matisse said:


> which water did you use? ashbeck spring from tesco seems to be the best for filter.


Im also interested to know which water.

Ashbeck is not a million miles off the Waitrose profile, its what I tend to use for beer brewing, although I alter the PH a little with gypsum


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## MWJB (Feb 28, 2012)

I got a lower level of extraction in side by side French presses using Volvic (quoted at ~120ppm? mine read a little less) vs tap water (hard ~300ppm). It was a bit of a tortoise & hare situation, sampled at different times, preference switched back & forth between the 2.

You might have to grind quite a bit finer with the mineral water.


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## dsc (Jun 7, 2013)

It's strange as the TDS values seems to be in the right range, I thought underextraction would affect TDS massively.

I'm using 5L bottles from Sainsbury, don't want to start using anything which is 1.5L only as it tends to be rather expensive (especially when you're warming things up with boiling water, rinsing paper filters and brewing with the same kettle / water). I've got a Brita filter, will give that a go, I also have a long forgotten TDS water meter, so will do some tests tonight.

Grind doesn't seem to affect it too much, unless I a good few ticks into the fine area and then it's a mixture of bitter / sour, which is even more bad.

Regards,

T.


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## MWJB (Feb 28, 2012)

dsc said:


> It's strange as the TDS values seems to be in the right range, I thought underextraction would affect TDS massively.
> 
> 
> > Out of interest, what would that range be? Extraction yield (specifically) might not always be as simple to calculate with the CCD as it holds a fair amount back sometimes.
> ...


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## dsc (Jun 7, 2013)

Right, just made a brew (Bosques de San Franscisco), checked water TDS, it's 90ppm on the mineral water and 270ppm on the tap, so I mixed them up to get a solution of 120ppm. Used 95degC brew water, typical 100g to bloom for 20s, top up to 400g, mix, cover, mix after 3min and drain. Had roughly 100g left in the Clever, thought it would be good, turned out otherwise, still rather sour, but less than previous brews, maybe I need 6-7min instead of 5min. The strange bit is the Mojo measurement, got 1.71%. Hmmm... not sure what to think.

Regards,

T.


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## MWJB (Feb 28, 2012)

Did you stir up the beverage before testing with the refractometer? Sounds like the mixing in the CCD should have taken care of that & evened out the TDS, but I find it's worth checking top & bottom of the beverage to see if there's any deviation.

There are 2 ways of looking at your TDS reading...

#1 As "extraction yield": Sounds like it may still a shade under in those terms, compared to my preference, maybe the sourness is accentuated by the pungency at such a high concentration? As sourness specifically is your issue, I'd grind finer...and/or see how much beverage is getting caught up in the mechanism...another 30g might not sound like much but it could carry enough dissolved solids to push you up nearly another 2% on the yield, maybe enough to add some balance?

#2 Steeped brews may have a reasonably even TDS accross the beverage as well as the retained brew water in the grinds... this can make "extraction yield" pe se less pertinent. The fact that the CCD brew steeps, then also drains through the bed (rather than being poured off it) confuses the issue...how much more TDS is picked up in the drain? I have been meaning to test the brew in the CCD & compare to the drained output, but everyday expenses have taken priority over buying syringe filters for now...









There, I seem to have sufficiently hedged my bets!









Have you tried tasting off the top of the CCD prior to draw down? Is the sourness there all along? Is it better/worse after draw down.

My best steeped CCD brews to date have either been either ~16% extraction yield, but more normally 20-21%...you may be between Scott Rao's humps? Push on to the big one...


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## dsc (Jun 7, 2013)

I always stir, pull into the syringe, bin and pull again to get a fresh sample.

I tend to drain for 60s, might not be long enough as I still have some coffee left in the Clever. Then again it depends on the TDS in the left overs, if it's super concentrated it will only add to the total TDS. I'll do a syringe filter TDS vs. drain brew TDS test tomorros, see what happens.

I have never tasted from the top of the Clever, again something to try tomorrow. Gave a sample to my missus, she pulled all sorts of faces and said it's super sour, I must be getting used to crap

Regards,

T.


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## MWJB (Feb 28, 2012)

dsc said:


> I tend to drain for 60s, might not be long enough as I still have some coffee left in the Clever. Then again it depends on the TDS in the left overs, if it's super concentrated it will only add to the total TDS. I'll do a syringe filter TDS vs. drain brew TDS test tomorros, see what happens.
> 
> Regards,
> 
> T.


If you let the remainder drain at 1.71% (it's not a given that the TDS itself will be rising significantly at this stage...it may be a little higher, or lower than what came out at 300g...but I suspect the TDS will have plateaued somewhat.. and you may end up with a little more in the cup then that will bring your yield up? Maybe clipping that last bit is part of the issue?


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## garydyke1 (Mar 9, 2011)

Today im using the CCD as a cupping bowl. However , when the brew tastes insanely good Ill drain it and see what its like.

Ill try this twice for fun. 1 x my mineral water blend and 1 x severn trent unfiltered


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## garydyke1 (Mar 9, 2011)

Our tap water - severn trent B32

Analysis Typical value UK/EU Limit Units

Hardness Level Soft No Standard Applies

Hardness Clark 3.00 No Standard Applies Degrees Clark

Hardness French 4.00 No Standard Applies French Degrees

Hardness German 2.00 No Standard Applies German Degrees

Aluminium 13.38 200 μgAl/l

Chlorine 0.49 No Standard Applies mg/l

Coliform bacteria 0.00 0 no./100ml

Colour 1.49 20 mg/l Pt/Co

*Conductivity 121.23* 2500 μS/cm at 20°C

E.coli bacteria 0.00 0 no./100ml

Fluoride 0.90 1.5 mgF/l

Iron 20.27 200 μgFe/l

Manganese 1.82 50 μgMn/l

Nitrate 1.75 50 mgNO3/l

Odour 0.00 Acceptable to customers and no abnormal change Dilution Number

Pesticides 0.00 0.5 μg/l

*pH 8.09* 6.5 - 9.5 pH Value

Sodium 8.04 200 mgNa/l

Taste 0.00 Acceptable to customers and no abnormal change Dilution Number

Plumbing Metals

Copper 0.01 2.0 mgCu/l

Lead 0.50 25 μgPb/l

Nickel 1.01 20 μgNi/l

Waitrose

Nutrition

Typical values per litre

Chloride 18mg

Magnesium 4.5mg

*Calcium 15mg *

Nitrates 7.8mg

Sulphates 17.8mg

Sodium 10.5mg

*Bicarbonates 39mg *

Potassium 0.8mg

*ph 6.7*

*
tds 105*


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## garydyke1 (Mar 9, 2011)

Ah, this is confusing.

My unfilter tap water .....(gulp)....wins









EDIT - it wins on taste, but NOT aroma.

I hate water


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## El carajillo (Mar 16, 2013)

I think most of Birmingham's water comes from Wales down two 48" pipes down the middle of the Bristol road .


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## garydyke1 (Mar 9, 2011)

El carajillo said:


> I think most of Birmingham's water comes from Wales down two 48" pipes down the middle of the Bristol road .


Youre right! Welsh mountain water...we call it birmingham wine. Ours is meant to be some of the best tap water in the world, however I find the chlorine very obvious.

I used to live on the bristol road, we had a private water supply from a well. It tasted lush and was very very clean. However the kettle showed obvious signs of scale after a single use


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## dsc (Jun 7, 2013)

Right then, more tests done and more frustration...I've done a test brew, 7min brew time this time, got 1.4%TDS via a syringe filter and 1.55% on the drained brew. Taste is still crap, now a mixture of sour and bitter, still tastes like it's underextracted, but TDS is saying otherwise







Now thinking about it I always get similar results with SQM coffees and mineral water, although now I tend to stick to water at 120ppm, so I'm lost as to what is going on. I've drained the whole lot this time, didn't leave anything in the Clever, but it doesn't make much difference.

Regards,

T.


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## garydyke1 (Mar 9, 2011)

What water do SQM use themselves when they cup production roasts?


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## MWJB (Feb 28, 2012)

dsc said:


> Right then, more tests done and more frustration...I've done a test brew, 7min brew time this time, got 1.4%TDS via a syringe filter and 1.55% on the drained brew. Taste is still crap, now a mixture of sour and bitter, still tastes like it's underextracted, but TDS is saying otherwise
> 
> 
> 
> ...


Grind finer. Steep until you get 1.50-1.60% TDS in the CCD, then drain. Or taste in the CCD until the sourness is gone, then drain & record (this might put you a shade over, but you'll see if you're going in the right direction).

I've had some stunning SQM coffees, some were stunning only once I hit the sweetspot...if you don't hit it, it's easy to wonder what the fuss is about.

I'm going to have a go at your brew ratio, see what I get & report back.


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## MWJB (Feb 28, 2012)

30g Hasbean IMM Guatamala San Patricio El Limon, fine drip grind, don't know exact setting, it's just what the Porlex is on, probably just a click or two back from 1 turn out?

401g 95C water.

Bloom with 100g 20 seconds

Fill to total, stir (3-4 back & forths for the length of the brewer base), cover.

2:30 stir again.

5:00 attempted botched, cheapo, homemade filtering of sample dropper, failed, took an unfiltered sample. Tasted, just past the point of maximum brightness, flattening off. If I was doing this by feel, I'd drain just as it got the zingiest, a little before this point.

6:00 started draw down.

12:00 draw down complete 330g in cup. I was dipstick tasting the output right up to the end, I was only really getting bitter choc in the last 10-20g, it was all palatable.

Unfiltered, undrained, sample read 1.71%TDS".

Beverage read 1.88%TDS (all my steeped brews in the CCD at this grind & espresso have been 20.6% to 21.6% extraction yield, steeps have been 4min to 10min, brew ratios from 56g/l to 75g/l, I think that grind drives yield much more than brew ratio & time with this method).

Taste: Syrupy, big mouthfeel, acidity is there, lively but not "sour", like a moka pot brew, concentrated, fruity, rich but no astringency...some dark cocoa, doesn't taste like I'd quite expect for this level of extraction. However, I don't find very focused flavours, I get fruit, juice, zing, vaguely citrussy, vaguely choc. It's not bad (it'd no doubt be better if I had a Guatamala) but not very refined.

I have been dropping my grinds into the water, rather than pouring water onto the grinds with the CCD steeps because I'm trying to get away from the syrupy mouthfeel and "generally safe, but generic" CCD brews. I feel the high brew ratio is making it too much of a smack round the head with blunt instrument, personally I'd back off to 64-65g/l and aim for 1.45%-1.50% TDS.

I've just had 6.5g of coffee in one hit, I can't stop typing....I want to run around and shout... my eyes are really big...is it hot in here, or is it just me...


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## MWJB (Feb 28, 2012)

Oh yeah, water was Volvic.


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## MWJB (Feb 28, 2012)

dsc said:


> Right then, more tests done and more frustration...I've done a test brew, 7min brew time this time, got 1.4%TDS via a syringe filter and 1.55% on the drained brew. Taste is still crap, now a mixture of sour and bitter, still tastes like it's underextracted, but TDS is saying otherwise
> 
> 
> 
> ...


Here's my crackpot theory on what may be going on...

1.58% TDS would be your normal target by my, possibly unique, reckoning.

Now the quandary, do you want that 1.58% in the brewer before draw down, or in the cup? My gut says extract it to 1.58% in the brewer (I don't like "leaps of faith"), draw down & any rise in TDS is just something you have to live with, there's no other practical way of getting the brew out, it may push your total yield up, but this isn't a pourover scenario...so what that 10% actually consists of (it's not the weak, bitter, diluted output you'd expect at the end of a typical drip brew) may not be that damaging/detrimental to the overall cup?


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