Iron in the water? Looking info how Fe effects the mash

[SnowRaven]

Is there information out there on how Fe Iron effects the mash
and what levels are desirable?

I have been reading up on water Chemistry in Brewing but have yet to see this addressed.

Any Basic Comments? I Looking for sources that are reliable for further research.

Or is it as simple as get all the Fe out?


(In my case I am on an artesian well in Mid East WI, we do have a Iron curtain (Bubble Column) but I am not sure what else this Iron Curtain removes. Thinking of taking the water for the brew liquor pre-softener, post curtain) (I also have a RODI for zero TDS water) So I have access to 3 water types - Softened / Column Filtered / RODI) (Raw has 11-14ppm FE not an option) Hoping Column Filtered gives me low Fe and keeps a desirable RA profile

 

[jeffjm]

I don't know about mash chemistry, but even a small amount of iron may result in metallic off-flavors. Keep it out!

 

[mchrispen]

SnowRaven,

Depending on your water profile - you should pass the softened water into the RO membranes to extend their life, with as much of the iron (and other metals) oxidized and removed beforehand. I believe that high concentrations of iron are particularly troublesome. There are likely other elevated mineral levels that accompany iron.

I brew solely with RO, built with salts to specific recipe profiles and have had good results. While it adds a step into by preparation process, it has been worth the effort and expense. RO, without any significant alkalinity, is easily manipulated through liquid acid, base additions and the salts themselves to achieve your target mash pH and flavor profile. I say this knowing that others will correctly argue that the accuracy/efficacy of those additions are reliant on verification with a calibrated pH meter and potentially dubious target profile information.

If your Column filtered water tests with very low iron (below 0.3 ppm I believe is the taste threshold), then consider dilution of that water with RO to achieve the appropriate target water. I would have that column water tested by Wards or another lab for brewing characteristics.

As for residual alkalinity in RO water, you can always deploy a little pickling lime or baking soda to add some alkalinity to the mash.

Peek at this for some information on metal levels for brewing - https://sites.google.com/site/brunwater/water-knowledge

 

[mabrungard]

Ironically, iron is actually a necessary component in brewing water since it is a trace element used by yeast. However, that trace level is well below the taste threshold that Matt points out above.

So...iron=yes, but not enough to be able to taste. If you can taste iron in your water or can see rusty staining, you probably need to employ some removal treatment.

 

[SnowRaven]

So if my thinking is correct

DI (De-Ionized) pure water would not be desirable either from the above comments
Makes me curious on how or if the solubility of brewer salts and buffers are affected when the water is zero TDS pure

 

[ajdelange]

Iron is very important for electron transport during respiration. But yeast don't respire (during fermentation). Iron may also be a co-factor for some enzymes but there is plenty in the grains for this purpose. There is, thus, no problem in using RO/DI water for brewing which is not to say that you can't improve the beer by adding minerals. You don't need to add iron. It should be below 0.1 mg/L for brewing applications.

Obviouly, de-ionized water maximizes the solubility of anything in it relative to water which contains ions i.e. it is further from saturation with respect to any dissolved substance.