Reverse Osmosis Water Filters and Scale

[pyro2b]

I''m looking for anyone with actual experience or factual knowledge regarding the use of Reverse Osmosis (RO) water in commercial coffee machines.

At home I have a Sunbeam EM6910 Cafe Series machine which I now run on RO water, with no problems, and no bitter taste to the coffee, it actually tastes better on RO water than on either straight tap water or through a bench top activated carbon water filter. This is a thermo block system using a vibrating pump and is NOT auto-filling.

My town tap water varies between 100 to 120 ppm, our RO water is 5 to 7 ppm.

I have concerns about the autofill sensors on a Rancilio machine working with RO water. I have contacted the two local agents for Rancilio regarding this, but they have no idea what the minimum electrical conductivity of water is required to operate the sensor. I have emailed Rancilio Italy twice with no response.

I have recently stripped down a Rancilio S20 that has been connected on our town water via a commerial grade 10\" water filter, and the amout of internal scale is unbelievable! Nearly 2kg of scale from around 5 years use in a small cafe!

I''m looking at using RO because I don''t want to see this amount of scale re-occur, and I want to stay away from the polyphosphate (Scale reducing) cartridges as I cannot find any long term health effects studies on its consumption in water. Besides whos wants man made chemicals in their coffee?!?!

I am thinking of adding a remineralising cartridge inline before the coffee machine, which will give around 15ppm hardness, but I am worried if this will just undo all the hard work of preventing the scale.

 

[Davec]

Our water is 360 ppm and VV hard. I use a RO system for my water. I have tested many different makes of coffee machines and have not yet found one where the autofill sensor will not work properly at TDS levels as low as 11 ppm. So I wouldn't worry about that.

I don't know about taste, I personally think it tastes better, even though many leading authorities say it makes it more bitter. My view, our water is full of crap (pesticides, flourine, chlorine, sediment, rust, organophosphates, calcium etc..) I can't imagine all this stuff benefits the taste of the coffee and prefer the "straight" RO water.

Commercial coffee machines would need a fairly good RO system to work, but they should be fine with it, certainly an old engineer told me once "salt softeners are great, there is nothing better for the machines", of course our food laws mean that salt softeners cannot be used in commercial premises for coffee machines.

I also did a couple of articles

http://coffeetime.wikidot.com/search:si ... 520osmosis

 

[ElPugDiablo]

Isn't 5 to 7 ppm too low? Most of the articles I read suggest 50 ppm for espresso extraction.

 

[pyro2b]

Davec,

Thanks for the info, I think I will just try hooking up a RO unit to the machine and see what happens.

 

[Carmine Domenaco]

My understanding is that RO water is not ideal for espresso or coffee as you need 50-100 ppm in order to get the best extraction from your coffee.

Most RO users I know actually add ppm back into the water at acceptable levels.

 

[morrisn]

We use a salt type water softener as well as filters to remove any sediment, taste, chlorine,etc and it works great. There is no reason you cannot use a salt type conditioner in a commercial application. In this type of softener the water passes through a resin tube which removes the minerals and after a set amount of water has run through it the softener goes into a cleaning mode which is set for a time you are not open. In this mode it puts the softener into a bypass mode then it brings water in through the salt and flushes the minerals off the resin tube into your sewer system and then flushes any salt residue out of the tube and then it comes out of bypass and starts softening the water again. So no salt ever gets into your water system.

 

[pyro2b]

The machine I had did have a industry standard water filter on it, I'm not sure what the actual cartridge consisted of, but it should have been activated carbon, possibly with some De-ionising Resin. It was set up in the cafe by Mocopan, who are the Australian Agents for Rancilio, so I assume they would use the manufacturer's reccommended filtration set up.
I know the machine came out of a busy cafe environment (5 minutes away on the same water supply) where the machine was only attended to when it broke down. However after 5 years of use nearly 2kg scale had accumulated in the machine (Our Total Disolved Solids in our water is only 120mg/l which isn't that high).
The machine has been donated to my church, which were hoping to just plug it in and turn it on and use it. I'm trying to prevent this from ever occuing again, I have already spent 6 or 7 days stripping down the machine acid bathing, grinding, sanding and cleaning. I know that this amount of effort would not normally be spent on such a machine, but the church can't afford to buy one, and I'm not charging for my time.

My other problem is that in Sydney they use Chloramine to treat the water, which cannot be readily removed by normal filtration on a longterm cotinuous basis. The other problem is that they also add Sodium Silicofluoride and Hydrofluosilic Acid to our tap water which they claim is for our health, but just check out the MSDS for these chemicals, especially the toxilogical data:

http://www.magitsurplus.com/PDF Files/Na2SiF6-MSDS.pdf

https://fscimage.fishersci.com/msds/11110.htm

I don't know who on earth would want these nasties in their coffee, I certainly don't!!!

Also Herbacides, Pestacides, Heavy Metals and dissolved salts CAN ONLY be removed by either distillation or Reverse Osmosis. As you can see from this graph

I'm looking at a system like this: (Click on the link for more information, as it talks indepth about RO compared to other filtration methods.

http://www.greenpastures.com.au/ind...ufacturer_id=0&option=com_virtuemart&Itemid=1