Demineralized vs Distilled Water

Water analysis, treatment, and mineral recipes for optimum taste and equipment health.

#1: Post by Grant »

So, for the last while, I've been using the potassium mineral recipe/solution into distilled water and been very pleased with things overall.

But, unfortunately, I can no longer get "bulk" distilled water here...the local shop is selling "demineralized" water instead. There seems to be varying opinions on how these differ, how sterile demineralized is vs distilled (they add ozone to their demineralized according to the label).

Has anyone delved into this and have any ideas, thoughts etc? They say their demineralized is run through 7 membranes and their testing shows virtually no difference...but my one truism in life is..."Never trust what anyone says if they are making money from it...."


#2: Post by Auctor »

Have you considered Zero Water?

RPavlis water formula and ZeroWater

(Full disclosure: my Zero water kit is arriving tomorrow, which I'm hoping is a cheaper, slightly more elegant solution solution than buying gallons of distilled water.)

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#3: Post by sadbox »

I'm guessing they are using a Reverse Osmosis process. If so, it does normally bring the mineral content down to extremely low levels, around 5% of the original. In most areas this will give you sufficiently low mineral content to the point where it would be indistinguishable from distilled for the purposes of coffee.

Luckily though this is something super easy to verify! Grab a water testing kit and see what level the water they actually give you is!
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#4: Post by walr00s »

I'm using ZeroWater for my base (then following RPavlis formula). Cheap, seems to work based on different testing kits I've purchased (Chris' Coffee and La Marzoco kits)

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#5: Post by Nunas »

The trouble with demieralized water is that there are multiple ways to produce it and, as far as I know, no standards. Distilled water, on the other hand is a well-understood process with consistent results. But, your post gives a clue to what you're getting in that they are using membranes (IE, RO). I've got a fair bit of experience with RO demineralization and am a bit puzzled by "seven membranes". That sounds like a bit of Madison Avenue terminology to me, as multiple membranes are generally used to increase volume, not purity. Even if they are cascading membranes due to severely hard source water, anything beyond two in series would be overkill. As for the ozone, demineralizing by some methods does not remove non-ionic elements, such as bacteria. The ionization is a way to kill these off. Usually they use UV light,or at least that's what we used many years ago. So, based on your post, I'd hazard a guess that using the demineralized to make up your espresso water would not be an issue.

Ha, ha, I just noticed that the auto-spell thing changed demineralized to decriminalized...I hope I found them all :lol: