Water profiling question - Magnesium

[Darren Waszkinel]

Hi all

A question for you all if i may.
I am currently using RO water for my brewing.
I have found a water profile online for a Juicy bits clone and i have setup a target profile in Brewfather. The values i was given was only included values for Chloride, Sulfate and Calcium but nothing for Magnesium.
I have read elsewhere that Magnesium is important for the mash and the fermentation but as you can see from the profile, there is currently none there.
Should there be Magnesium in the water profile ?
Is there a number that people often use ?
Any help/guidance on this would be very much appreciated

 

[MHB]

Much debated.
One school of thought is that anything Mg can do Ca can do better. Its true that we need some Mg in the mash its an important enzyme cofactor, along with a heap of other minerals like Zinc, Copper, Iron, Manganese... Fortunately there is enough of most of these in the malt and they go into solution when you mash in.
There is another school of thought that all you really need is Mg. The guy from Bru'n Water (Posts here occasionally) appears to be of this persuasion. Its an idea that keeps cropping up every couple of years and has since the 1970's or early 80's.
Note that brewing literature and brewing schools keep talking about the importance of Ca, so meh, Ca will do for me.

One thing you might want think about is Zn. If you are using RoMo water and Australian malt it might be worth thinking about adding a touch of Zn. Australian malts are grown in the oldest soil on the planet and a lot of them are Zn deficient.
German brewers where they cant add stuff like Zn talk about the importance of doing everything they can to get Zinc out of the malt and into solution, including some pretty extreme measures that you wouldn't even think of doing without the Reinheitsgebot looking over your shoulder.
Mind you be careful, we are talking trace amounts like 0.1-0.2ppm but it can make a big difference.

For mine, go with the water profile you have, I would be tempted to add a teaspoon of yeast nutrient to the mash, being made up of digested yeast (in part) it contains most of the trace minerals you need if you want to be sure.
Mark

 

[wessmith]

Much debated.
One school of thought is that anything Mg can do Ca can do better. Its true that we need some Mg in the mash its an important enzyme cofactor, along with a heap of other minerals like Zinc, Copper, Iron, Manganese... Fortunately there is enough of most of these in the malt and they go into solution when you mash in.
There is another school of thought that all you really need is Mg. The guy from Bru'n Water (Posts here occasionally) appears to be of this persuasion. Its an idea that keeps cropping up every couple of years and has since the 1970's or early 80's.
Note that brewing literature and brewing schools keep talking about the importance of Ca, so meh, Ca will do for me.

One thing you might want think about is Zn. If you are using RoMo water and Australian malt it might be worth thinking about adding a touch of Zn. Australian malts are grown in the oldest soil on the planet and a lot of them are Zn deficient.
German brewers where they cant add stuff like Zn talk about the importance of doing everything they can to get Zinc out of the malt and into solution, including some pretty extreme measures that you wouldn't even think of doing without the Reinheitsgebot looking over your shoulder.
Mind you be careful, we are talking trace amounts like 0.1-0.2ppm but it can make a big difference.

For mine, go with the water profile you have, I would be tempted to add a teaspoon of yeast nutrient to the mash, being made up of digested yeast (in part) it contains most of the trace minerals you need if you want to be sure.
Mark

You heard about the large German brewery that installed a galvanised ladder inside its mash tun.........

 

[MHB]

Yep, other odds and ends like galvanised paddles in the mash mixer, bits of gal chain bolted to stirrer blades, using gal plumbing on cold water feed pipes...
Apparently letting some expended malt sour for a couple of days to get it acidic, extracts much more of the Zn then using it in later brews (or a sterilised extract from), pretty stinky, but gives some idea of how important Zn is. Continental malt has much more Zn than Aussie malt, their water tends to have more to.
Had a look at the water profile for Blizzard (basically snow melt) municipal water isn't even Chlorinated, just filtered and UV sterilised, but the Zn was in the low PPB range.

Considering the dilution I would be tempted to make up a mother solution and use a chamber bottle or similar, to avoid operator errors.
Like trace elements around a citrus tree, not something you want to put too much of, but some can really matter.
Mark

 

[mabrungard]

Magnesium can be an asset in brewing well-bittered beers since Mg adds a bitter note. However, there isn't a great need to add much Mg when brewing other styles. In a NEIPA, I wouldn't add more than about 10 ppm to the brewing water. Malt provides ALL the Mg that the yeast needs for their metabolism. But having a bit of Mg in the water does aid in yeast performance.

 

[MaggieO]

As a general rule I put 1/4 teaspoon of epsom salts in every batch I make, usually three gallons.

MaggieO