jpender Senior Member Joined: 11 Jul 2011 Posts: 401 Location: California Expertise: I like coffee
Grinder: Kyocera CM-50 Vac Pot: S/S Moka Pot Drip: Aeropress
Posted Wed Feb 27, 2013, 8:50am Subject: Who understands water?
Our water is quite good, very clean and straight from the Sierra Nevada mountains. They don't even have to filter it, just treat with UV and a touch of chlorine. It tastes great, but is it ideal for coffee? Can anybody tell me?
Lee_M Senior Member Joined: 2 Dec 2012 Posts: 42 Location: Los Angeles Expertise: I live coffee
Grinder: Baratza Encore Drip: V60 Roaster: Popper
Posted Wed Feb 27, 2013, 10:20am Subject: Re: Who understands water?
The limited information I've been able to find suggests that your water is nearly optimal for coffee. Cirqua (now Global Customized Water) recommends the following:
Based on your numbers, the only adjustments you might consider are a small addition of calcium chloride or calcium sulfate to raise hardness and TDS slightly, and possibly a small addition of lactic or phosphoric acid to lower your pH. It's probably worth buying some test strips and double checking the pH of your water. You can use a brewing water calculator (such as: Click Here (www.brewersfriend.com)) to calculate your water adjustments.
As for the flavor impact of specific ions (e.g., chloride, sulfate), I have not found any information. If anyone has access to this article, I imagine they'd find some useful stuff.
jpender Senior Member Joined: 11 Jul 2011 Posts: 401 Location: California Expertise: I like coffee
Grinder: Kyocera CM-50 Vac Pot: S/S Moka Pot Drip: Aeropress
Posted Wed Feb 27, 2013, 2:41pm Subject: Re: Who understands water?
Thanks, Lee. I'm not certain whether or not I can get that paper, but it appears that you can rent a read-only copy for 99¢, as if it were DVD from Netflix.
Posted Thu Feb 28, 2013, 12:40pm Subject: Re: Who understands water?
You'll find the pH can change dramatically with no changes in the rest of the parameters.
Just take a sample of water, shake it in a jar with some headroom, then re-measure pH. The added CO2 will drop the pH, even at 300ppm in the atmosphere.
If you run water through a fine pore carbon filter, you'll find the TDS migrates toward the hardness value + magnesium. Basically, TDS is the same thing you'd get if you dehydrate the sample of water. In your case, the tap water would yield 0.132g of solids if you dehydrated 1 liter (1kg) of your water. Some of that is calcium/calcium bicarbonate, some of it is magnesium/magnesium bicarbonate, and there's also some of the other permanent hardness minerals (sulphates and chlorides of calcium and magnesium, oxides of iron, etc.). Those are the things you would need a water softener to remove.
The measurements are in CaCO3 equivalent (German degrees, but 1deg = 17.4ppm or something like that).
Theoretically, alkalinity (sometimes called temporary hardness) is supposed to be able to boil out of the water. Heating water drives off CO2, as the solubility drops this reduced acidity causes the calcium and magnesium to precipitate out.
Total harness - alkalinity = permanent hardness.
Because of the variation in water pH at any given time (depending on temperature, dissolved CO2, etc.), there is a tendency for water at ~room temp, exposed to atmosphere, to reach an equilibrium pH that is closely related to alkalinity. 49 ppm implies an equilibrium of right around 7pH, I remember in my head that "fifty is neutral". It probably comes out of the tap at 8, quickly reaches 7 after exposure to atmosphere (or possibly lower), but ends up right back around 7 once heated.
Total hardness and alkalinity will drop once you boil the water - you should see this in two ways:
1) make a cup of tea with your water. If it makes scum, this means that you probably have precipitation of calcium and magnesium bicarbonates into carbonates. 2) take a cup of your water, then boil it for a few minutes. Inspect it afterward - if you see floaties, then this is another view of "temporary hardness". You can actually filter these out, and the resulting water will technically be softer.
While this seems simple, it's actually too simple, but it's a starting point of understanding water and water quality.
A guy named Buswell did a paper showing that alkalinity and temporary hardness are not EXACTLY the same thing, and the intro kinda explains the relationship between alkalinity, temporary hardness, permanent hardness, total hardness:
The total hardness of a water is a measure of the calcium and magnesium salts, carbonates, sulphates, etc., present in the water. The temporary hardness is the amount of calcium and magnesium salts which are precipitated by thorough boiling. This precipita- tion is due in part to the decomposition of bicarbonates to form the less soluble carbonates, and in part to the hydrolysis of carbonates and sulphates. The permanent hardness is the hardness after boiling. Thè alkalinity is the sum of the carbonates and hydroxides of the alkali and alkaline-earth metals. So many writers1 state, or lead one to infer, that "temporary hardness" in water is equal, or nearly equal, to the "alkalinity" that it seems worth while to call attention to a few typical analyses in which the temporary hardness differs widely from the alkalinity. Data will therefore be presented to show that there is a veiy considerable alkalinity in many waters after boiling
Indeed, I've done this exercise - and while my alkalinity is high and comes down significantly after boiling, it definitely does NOT go to zero after boiling. That same paper (written in early 20th century) goes on to say that "temporary hardness" term should be abandoned.
If you have the Calcium and Magnesium, then total hardness (if the total hardness is only by calcium and magnesium ions - if you have iron that would have to be added too) ~ 2.5*Ca + 4*Mg. The rest of the difference is other elements that contribute to total hardness.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Thu Feb 28, 2013, 12:41pm Subject: Re: Who understands water?
The good news - from a technical standpoint you won't see an effect of water hardness going from distilled to 350ppm on extraction calculation.
You WILL taste the difference, though.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Thu Feb 28, 2013, 12:45pm Subject: Re: Who understands water?
oh, and even at 500ppm, the amount that is contributed in solids to a cup of coffee is small.
If you dehydrate 100g of coffee at 1.5% strength, and the water is 500ppm TDS:
Coffee TDS=1.5g TDS from the water = 0.05g
In your case = 0.0132g
Basically noise.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
tdifraia Senior Member Joined: 13 Dec 2012 Posts: 75 Location: Boston Expertise: Just starting
Espresso: QM67 Grinder: Baratza Vario Drip: Bunn
Posted Fri Mar 1, 2013, 1:46am Subject: Re: Who understands water?
You water is very good for drinking. It is slightly alkaline and has a lot of minerals. It is very healthy and I would drink lots of it if I were you. As far as for making coffee, thats another story. Certain minerals such as calcium and magnesium under high temperatures will precipitate out of the water and become solids (scale). The alkalinity (49ppm) will help prevent any corrosion, and gives you an indication of what portion of the calcium in your water is calcium carbonate or temporary scale, also called limescale. This scale is the better scale because it is soft and can be cleaned off easily. The other scale (Ca 13ppm and Mg 4.9ppm) is permanent scale and will stick to metal and act as an insulator. This scale is very hard to clean. Acid cleaning is somewhat effective but can cause more problems than do good, and is alot of work. Hard scale also acts as a very effective insulator and effects heat transfer considerably. People use RO's and water softeners to remove these minerals. Which is great for espresso and coffee machines. With RO and softened water your machine will not scale up. RO and softened water does have other drawbacks. What gives water its taste is the minerals. When we drink water we are consuming the minerals in it. Not only does it give us its taste, it supplies our bodies with trace minerals necessary to survive. So RO and softened water is great for washing machines, swimming pools, boilers etc... But not really healthy for drinking. It will not hurt you, but it will not be a healthy choice and may taste flat because of the lack of minerals. When you are using RO or soft water for coffee, I do not think it will effect the taste noticibly because there are so many flavors extracted from the coffee. Your waters total hardness is a little high 57 ppm is equal to approx. 3.5 grains per gallon. I would use a Brita water filter, which helps remove some of the hardness and you should be fine. Generally you want to be 3 grains or less to prevent scale build up. The greater the hardness the greater the scale build up. I definately would NOT add any hardness to it like someone suggested. Your water is fine for coffee. Invest in a Brita water filter and check your waters hardness once in a while. I hope this helps.
jpender Said:
Our water is quite good, very clean and straight from the Sierra Nevada mountains. They don't even have to filter it, just treat with UV and a touch of chlorine. It tastes great, but is it ideal for coffee? Can anybody tell me?
jpender Senior Member Joined: 11 Jul 2011 Posts: 401 Location: California Expertise: I like coffee
Grinder: Kyocera CM-50 Vac Pot: S/S Moka Pot Drip: Aeropress
Posted Fri Mar 1, 2013, 11:23am Subject: Re: Who understands water?
All very interesting. So should I treat my water for the coffee or just leave it as is?
There isn't any noticeable scale in any of our cookware, the bottom of my moka pot, or the tea pot which is used to boil water regularly and sits with some water in it 365 days a year (we never clean the inside of it). So I don't believe we need to purify the water. I was wondering if it might benefit from some small additions, as Lee suggested.
Posted Fri Mar 1, 2013, 12:16pm Subject: Re: Who understands water?
jpender Said:
All very interesting. So should I treat my water for the coffee or just leave it as is?
There isn't any noticeable scale in any of our cookware, the bottom of my moka pot, or the tea pot which is used to boil water regularly and sits with some water in it 365 days a year (we never clean the inside of it). So I don't believe we need to purify the water. I was wondering if it might benefit from some small additions, as Lee suggested.
Personally, I wouldn't treat the water. It's very likely that in your case a healthy chunk of your alkalinity is actually permanent (i.e. like I've seen, the alkalinity won't disappear after boiling the water).
Have you tried brewing coffee with distilled water as a baseline? I'm certain you could taste the difference.
"by the numbers", your water should be pretty much in line with suggested limits for water quality and coffee making.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
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