Does reverse osmosis water filter prevent scale buildup? - Page 2

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

LaCrema wrote:So... the big question is, which is going to cause more damage; RO treated water over time to brass and copper or spring water with mineral buildup?
Why worry? Use spring/re-mineralized RO water and descale. These simplified instructions take less than 30 minutes and a pound of citric acid will last for years. It's especially easy for your La Cimbali Junior since the boiler has a drain (d):

Dan Kehn


#12: Post by draino »

Hi all.

I came upon this thread researching water for a direct plumbed machine. I currently have a Silvia and would really like to upgrade to a Vetrano for the steaming power and rotary pump. I have a water softener for the house, but also have an RO system for drinking as the slightly salty taste of the softened water is not to my liking.

Anyway....the question is whether to hook up to the RO or the softened tap water. What are the issues with taste? It seems that some folks suggest a calcite cartridge for RO while others like the plain RO and some prefer just the softened water. Help!


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#13: Post by drdna »

There is no question that the flavor of espresso is affected by the presence of minerals dissolved in the water. The tests that I have run with fractionated samples of espresso prepared with varying mineral salt concentrations suggest that this is due to the direct impact of the minerals on taste, NOT on any alteration of extraction or interaction with the solutes in the espresso solution.

There is a simple answer. Use RO or distilled water in your machine to minimize scale, but add a back a pinch of salts to your basket/portafilter before you extract. I have prepared ahead of time a batch of salts (sodium, potassium, calcium, sulfur, etc. based on the chemical analysis of my favorite spring water. I add a pinch of this to the basket after tamping. It works like a charm, is very simple to do, and eliminates scale buildup issues.



#14: Post by draino »

Adrian, would you care to share your proprietary formula? Is descaling that much of an issue with HX machines?

Assuming that I choose not to go that route, and that minerals are important, would RO +Calcite addition be better than plain softened water?


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#15: Post by drdna »

I use an admixture to achieve a final solution of:
Calcium 94 mg/L
Magnesium 20 mg/L
Sodium 7 mg/L
Potassium 1 mg/L
HCO3 250 mg/L
SO4 120 mg/L

This is very simple to make, using a mixture of baking soda, calcium carbonate & magnesium oxalate (easily obtained as vitamin supplements) and black salt.

Regarding RO water, I would try it both ways and just see what you prefer. I think you will find the water with added calcium to make more flavorful espresso.


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#16: Post by another_jim »

Now that's a trick I never thought of, remineralizing the water in the basket. Why the sulphate?
Jim Schulman

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#17: Post by Marshall »

drdna wrote:The tests that I have run with fractionated samples of espresso prepared with varying mineral salt concentrations suggest that this is due to the direct impact of the minerals on taste, NOT on any alteration of extraction or interaction with the solutes in the espresso solution.
The coffee industry has a great deal riding on which methods produce the best extractions. To this end they directly and indirectly employ a large number of chemists, who have conducted a great deal of testing. I believe their fairly unanimous conclusions disagree with you. That doesn't necessarily mean you are wrong, just that better controlled and more extensive experiments than kitchen table tests would be desirable before jumping to your conclusion.

Here is a suggestion. Why don't you contact a respected chemist in the industry like Joseph Rivera (through SCAA) or Dave Beeman at Cirqua Water Systems and discuss their test methods and conclusions? I think it would be enlightening for all of us.
Los Angeles

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#18: Post by mgwolf »

Adrian, What admixture are you using. I.e., per liter, how much baking soda, etc? Can you tell me what ingredients, how much. I have the Mini and am using RO water. The taste is fine, but I'm always happy to have better. Also, I didn't realize RO was hard on copper which sounds costly. Thanks in advance. Michael


#19: Post by JackJ »

I get r.o. water in refillable 5 gal bottles from the natural foods store. I believe I've read that these commercial dispensers may either leave or intentionally add (through a calcite filter, I guess) minerals in some cases. Are there certain test strips (or other inexpensive means) that are accurate enough to let me know the mineral content of treated water? (As opposed to the gross mineral overload that comes out of my tap.)

I've wondered about doctoring each 5 gal. bottle to reach the best balance. I'm imagining an alka seltzer-like tablet that I can drop in, and which will fully dissolve and distribute itself. Might such a thing exist?



#20: Post by Les »

I too am about to upgrade (to a db machine), and I've been trying to put together a water strategy, taking into account the various issues. Here's what my thoughts are so far:

• Pure RO water causes the boiler to leach, will foil the autofill on plumbed machines, and is flat tasting (I think so anyway), but adding minerals to the water will cause some scale.

• drdna suggests adding a mineral mixture to the basket (sounds brilliant, but haven't tried it yet); if that works for taste, then the issue is how to best protect the machine.

• I can get a small RO system just for the espresso machine for under $300, and my water is so hard the tech has said it might leave enough minerals to solve the negatives of an RO system on the machine; if not, we can add a calcite filter.

• And of course, I could just put in a small cation system.

I am thinking of either using RO remineralized and descaling, or using cation. Any thoughts?