I recently installed a water drop RO/UV with a remineralization filter. I've been trying to find information regarding the optimal parameters for espresso extraction and machines. The attached image has what I read was SCA recommended parameters vs the tap scores I received after sending in a sample of my water for analysis.

Are my parameters too far off for optimal extraction ? Also, is the CSMR level harmful for my Lelit Bianca? If so, is there anything I can do to my current water filtration set up, to reach optimal levels? Would a different remineralization possibly help? I appreciate any feedback or insights!!

TampMore wrote:Are my parameters too far off for optimal extraction ?

I think you are probably fine. With RO and a typical remin cartridge, which adds a tiny amount of calcite (CaCO3) you expect a small but equal calcium hardness and alkalinity. Your numbers don't show that, but it can be hard to accurately measure these low levels. You might try a better measurement kit. If you use the inexpensive API fishcare kit you can get better precision using a 10 ml (rather than 5 ml) sample. With a 10 ml sample, each drop corresponds to 8.9 ppm as CaCO3. With RO and remin, you expect water that is softer than typical recommendations, similar to what they live with in Seattle, Portland, Vancouver, Oslo, Melbourne, etc., where many espresso shops brew perfectly tasty coffee.

TampMore wrote:Also, is the CSMR level harmful for my Lelit Bianca?

Chloride Sulfate Mass Ratio (CSMR) is a crude measure sometimes used to evaluate corrosion risk in household plumbing situations that involve potential lead leaching and galvanic corrosion. Not very useful in evaluating espresso machine risk. For the espresso machine you especially want to look at your chloride ion number in relation to alkalinity. If your chloride is below 15 mg/L, which I'm sure would be the case in an RO + remin cartridge situation you should be fine. (If you use a blending valve for remin, and if your source water is high in chloride, than you may have a concern.)

Thank you for that information! So I forgot to mention, I didn't use an at home kit, I used Simplelab- Tap Score, and sent them a sample by mail for analysis.

TampMore wrote:I didn't use an at home kit, I used Simplelab- Tap Score, and sent them a sample by mail for analysis.

In that case you should have also gotten a chloride ion value as part of the test.

What are you using for remineralization? If calcite or similar, and if it's not depleted you certainly expect to see measurable calcium hardness. If depleted you need to replace it.

My Chloride score is 8.38 ppm... some others- Potassium: .324 ppm, Sodium: 7.36 ppm...

I am using the Water Drop brand remineralization filter. Perhaps I'll looking into replacing or upgrading to a better one if possible.

That chloride number is OK although is higher than what you normally expect from an RO system.

TampMore wrote:I am using the Water Drop brand remineralization filter. Perhaps I'll looking into replacing or upgrading to a better one if possible.

That remin filter is reportedly full of nonsense minerals, but should be adding a small amount of calcium when fresh. I think replacing it with a conventional calcite or calcite+corosex in line filter would be a good move.

Ok, sounds good. I'll look into some other/better options than their remin filter. I really appreciate all the help and insight!