Does Magnesium Matter?

[whovous]

I use Bru'n Water and start with RO water; i.e., water with essentially no chemical content. When I build up my water, one of two things always happens:
1) My water has less magnesium than does virtually any other water profile I can find; or,
2) If I add, say, Epsom salt to build up the magnesium, my chloride or other numbers go out of whack.

Should I just ignore magnesium when creating water profiles? It seems like more trouble than it is worth. Does it do any good for my beer?

 

[Silver_Is_Money]

I recently was informed that there are ample loads of magnesium present within barley malt grains. If this is true, then magnesium deficiencies can likely be ignored.

 

[McKnuckle]

I always ignore it for the reason above, and my observation over roughly 50 batches of water-adjusted beer that omitting it didn't seem to matter.

 

[ajdelange]

Magnesium ion is bitter so most people don't like it. If you check the water profile for Schimmelsberg you may find that it contains some magnesium and so the naive assume that to make an authentic Schimmelsberger they must have magnesium in the water. What they aren't thinking of is that the Schimmelsberg brewers may well have done everything within their power to get as much of that magnesium out (split treatment with lime) and would have happily gotten rid of the rest of it if they could. OK, to be really authentic your Schimmelsberger should have as much magnesium as the original but your Schimmelsberger may be better than the original without any at all. Or not. Someone will chime in and say 'I find that the high magnesium in the Schimmelsberg bore waters supports the aromatic maltiness given to the barley cultivars grown in in the Schimmeltal morain derived soils due to the high zirconium content of those soils'. If you buy that then by all means use some magnesium in your liquor. It's easy enough to get a rough idea as to what magnesium is going to do to your beer by adding a pinch of epsom salts to a glass of it brewed without any. Like the result? Use MgSO4 the next time you brew. It's really up to you to decide.

 

[mabrungard]

Since malt supplies all the Mg that the yeast need for their performance, only add Mg if you want its effect of increased bitterness. I find that pale ales and IPA's are the only time I add Mg.

With that said, if your water has modest Mg content (<20 ppm), I wouldn't worry too much about it being too high. There are plenty of brewery water sources that have modest Mg content and they are still fine beers.

 

[whovous]

Thank you one and all. I've resolved to stop thinking about Mg until the next Schimmelsbergerfest.

 

[ajdelange]

I believe that's the week after St. Schleppfuß Tag.