Purified vs spring water and espresso quality?

Water analysis, treatment, and mineral recipes for optimum taste and equipment health.
twisterlove
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#1: Post by twisterlove »

Hi folks,

I acquired a lever la pavoni a couple of months ago. I got to making nice espresso shots. Then, suddenly, my shots got bad, where I get a good shot once in about 6 shots. I thought it was mainly temperature; I fixed the temp issue by attaching thermos. Yet, my shots are not consistent.

I found later that I started with Spring water, and at that time I get nice shots. Then, I switched to purified water, and that is when I got inconsistent shots. When I got back to using Spring water I again get nice shots more often, even though I brew sometimes at different temperatures.


I wonder if this is universally valid, given I pull on a lever La Pavoni, which is a challenging machine!

chrisbodnarphoto
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#2: Post by chrisbodnarphoto »

By 'purified' water, do you mean distilled water?

There are plenty of good water for coffee articles on this forum and others, but the basic is this :: coffee needs to have water that contains minerals to be drinkable in taste (you'll find various 'recipes' or comments on exactly which ones). Since distilled water contains zero minerals, not only will the taste be fairly terrible, but it can cause issues with more advanced machines, as different types of sensors require mineralized water to operate ... Even tho I don't think your La Pavoni would be much of an issue in that regard, but I'm not an expert on that.

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OldNuc
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#3: Post by OldNuc »

Adding "minerals" to the water is how you end up with boiler scale and heater failures. Boilers and associated heating elements experience the longest trouble free service life using pure water that is properly buffered to control Ph. This search result will shed some light on the chemistry involved with pure vs. designer water. /search-res ... &sa=Search

emradguy
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#4: Post by emradguy »

Definitely read, read, read all you can get your hands on regarding water quality for coffee. There's even a book dedicated to it.

There's more to it than taste of the water (which is clearly important and should hold up on its own - ie, if you don't like the taste of the water on its own, you probably won't like the coffee you make with it) and scaling potential, as extraction of various compounds found in the beans is affected by mineral concentrations and pH of the water. It's a very complex subject that one could write their PhD thesis on. Fortunately, we don't need a degree in biochemistry to understand the general principles, but we do need to do some reading and learning if we want to control our source water. The alternative is to use bottle spring water from particular sources (such as Crystal Geiser) or get expert help from a vendor that sells filtration/treatment systems designed for coffee (stick to the coffee retailers you buy machines and grinders from)
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rpavlis
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#5: Post by rpavlis »

The real problem with water from wells, springs, etc. is that it is variable depending on rainfall, etc. Furthermore water that is contaminated with massive amounts of calcium and magnesium has a constantly varying composition whilst espresso is being made from it as the Ca and Mg precipitate out in the boiler and group.

Look at the K, Mg, and Ca analysis of coffee. The amount of these elements in the coffee beans at the brew ratios used for espresso is large relative to even the most Mg and Ca polluted water. The beans have remarkably little sodium. Some beans tend to have more Rubidium than sodium, the element under potassium on the periodic table. This means the sodium in water will have a significant effect on the quantity of it in the espresso. Some people seem to like lots of Na in their espresso, others dislike it.

What does matter, and it can matter a lot is the concentration of pH buffers, especially bicarbonate. If one use beans that are dark roasted, near to being cremated, the decomposition of things in the coffee leads to a lot of basic material so that the stuff is apt not to be acidic. If one use less severely roasted coffee lots of the acids in the coffee as well as some formed in early roasting will be in the coffee. This will lead to noticibly acidic coffee. Bicarbonate ion added to this will have a profound effect on flavour.

It seems to me that it is utterly foolish to state that any special water is wonderful because the only water that has a constant composition is the water mixed on the spot. Bicarbonates seem to be about the only thing to add that do not dramatically change the natural ratios of things in the coffee and make a chemical brew instead of a coffee drink. Because coffee contains massive quantities of potassium, K, potassium bicarbonate is a natural choice of a compound to add to adjust pH. It is weakly basic, stable, and does not destroy boilers. It, in fact, leaves boiler pH near the point where there is least chance of corrosion, which by accident seems to correspond to best flavour. Potassium bicarbonate is readily available and is used in wine production to avoid adding things to the wine not naturally in the grapes. Potassium bicarbonate is readily available in food grade.

One can take pure water and add potassium bicarbonate to taste. One will find that the lighter the roast, the more bicarbonate will be required to avoid having sour coffee. The bicarbonate will also effect what compounds in the coffee will be eluted, because the ratio of acidic to basic forms of acidic and basic compounds will change.

One might find one likes Na in coffee. Then one can use sodium bicarbonate instead of potassium. I have noticed that many people really dislike sodium rich coffee. It is a bad idea to add chlorides in any form to boiler water because chloride complexes many metals, like copper, and brings about corrosion. They can also add a brine flavour.

The important thing to realise here is that one can adjust the amount of potassium bicarbonate to individual beans. It does result in still another variable, but it is still one that should be controlled for optimal results. A good place to start is to try 100 mg/litre. Inexpensive electronic balances can weigh accurately enough to do this, or one can make 10% stock solutions and pipette the stock solution into the pure water.

No scale will form, and, with copper boilers, a very good protective oxide layer will form on the surface preventing corrosion.

Again, the amount of potassium bicarbonate added can profoundly effect flavour. With plumbed in machines there can be problems, but otherwise one can mix up water to order.

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CoffeeBar
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#6: Post by CoffeeBar »

I have used spring water before but not noticeable taste different from my home water Purifier system. I am much concerned the US water has many added Commercial Fluoride and Chloramine,( The same in China as well ) So, I am only using the best water purifier system only.

Here are my simple setup

First stage: Unicel , 1 micron absolute sediment water filter and 0.35 micron ratings use a multi-ply laminate for particle retention. Ideal for Cryptosporidium and Giardia cysts reduction to 99.9%

2. Pentek CBR2-10R Carbon Block 0.5 Micron Filter w/ Flow Restrictor

Last stage: Aries (4 lb) KDF-55/GAC Filter

Now, your water will be very safe and taste good even in Coffee :D

HBchris
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#7: Post by HBchris »

I have a water related question,

I have been using Poland spring natural spring water, here is a link to their 2015 water analysis report:

http://www.nestle-watersna.com/asset-li ... PS_ENG.pdf

(page 17)


In my own testing, it had the following specs:

TDS: 61

using hardness test kit for GH and KH:

GH: 2 drops ( according to kit, 3 drops = 50ppm)

and seperately tested,

KH: 2 drops ( according to kit, 3 drops = 50ppm)


However using the La marzocco water calculator:
http://techcenter.lamarzocco.com/jsp/Te ... ulator.jsp


if i put the specs in with PH at 7

It tells me,
"water effects on Equipment: Heavy Corrosion"


does this seem correct? Will the above water cause an issue with scale or corrosion ? or maybe i am filling in the la marzocco form wrong.

your help appreciated.

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homeburrero
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#8: Post by homeburrero »

HBchris wrote: ...It tells me, "water effects on Equipment: Heavy Corrosion"
does this seem correct? Will the above water cause an issue with scale or corrosion ? or maybe i am filling in the la marzocco form wrong.
You are entering in the correct numbers. I don't know for sure what's under the covers of that LM water calculator, but I think it's doing a simple Langelier saturation index calculation, and if the numbers go negative enough it gives you that red "heavy corrosion" warning.

Your Poland spring water certainly would not scale. And as for corrosion, I think it's more complex than that.

For example, if you plug in a reasonably safe (non-scaling) water like this:
TDS = 100 ppm
hardness = 49 ppm
pH = 6.9 ppm
alkalinity = 42 ppm
chloride = 0 ppm
(all the other numbers 0 ppm)
Then that calculator gives you the same "Heavy Corrosion" red warning.

Or, for a more illustrative test, try plugging in values that correspond to Dr Pavlis' 100 mg/l potassium bicarbonate water:
TDS = 100 ppm
hardness = 0 ppm
pH = 7.1
alkalinity = 50 ppm
chloride = 0 ppm
(all the other numbers 0 ppm)
Then the calculator gives you a "Corrosion Intolerable" warning. And I'm very confident in Dr Pavlis' expertise about water and corrosion, and would not hesitate to use that water in a prized vintage machine.

So my opinion is that one needs to take those corrosion warnings from the LM calculator with a grain of salt.

Having said that, that Poland spring water does appear to be variably soft to very soft, with low (under 40 ppm) alkalinity, with a small but variable amount of chloride ion, and therefore may not be your best choice of bottled water.
Pat
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LDT
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#9: Post by LDT »

For rpavlis:
Locally, I can only find potassium carbonate and not potassium bi-carbonate. I know the molecular structure is different, but I do not understand the water chemistry. Are they interchangeable in your water formula? :?:

OldNuc
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#10: Post by OldNuc »

This is where I buy the potassium bicarbonate: https://nuts.com/cookingbaking/leavener ... onate.html They sell other goodies as well. :wink:

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