Oh come on! That 42.5 ppm Mg
level is just a quote from that source. There is no way that we can
define it as 'optimum'. The other thing that you should take away from
that article is that the malt contributes 100% of the Ca and Mg that the
yeast need for their fermentation. Adding any more of those ions via
the water is at the brewer's discretion and should be made based on
their goals. For instance, if you wanted the beer to clear rapidly, then
do add Ca. If you want more Cl or SO4, then the brewer might consider
more of a salt that contains Ca or Mg to supply those anions for flavor.
I wouldn't worry too much about the Mg:Ca ratio, but it is
important to recognize that you may not want to add a boatload of Ca to
your brewing water and push that ratio into an unfavorable range. You
should recognize that the additions of Mg and Ca to the water are
typically going to be modest in comparison to the concentrations of
those ions added by the malt. So as long as you aren't overdoing mineral
additions in the water, your wort is probably going to be in an OK
range.
Regarding starter preparation, yes it may be reasonable
to add a Mg salt to the water. I suggested that in the article as a way
to help infuse the yeast with a little extra Mg for the main ferment.
However, I suggest that you might best prepare your yeast by generally
mimicking the water profile that you will be brewing that next batch
with. I wouldn't worry too much about it though.
Let me correct
your take home message! Ca additions for the mash ARE beneficial since
they help precipitate oxalate from the wort. I suggest that all brewers
always include at least 40 ppm Ca in the mash for that purpose. But that
does not mean that your overall Ca content in the kettle needs to be
that high. For my recent lagers, I've been adding Ca salts to the mash
and none to the sparging water in order to end up with low Ca content in
the kettle. So target at least 40 ppm Ca in the mash and whatever you
want in the kettle (may be higher or lower). By the way, the latest
supporter's version of Bru'n Water includes a setting so that you can
tell the program that you want to add all the sparging minerals to the
mash to create the technique I mention above. The program also reports
the ion levels in the mash and kettle separately so that you can assess
that you are boosting that Ca level to that desirable 40+ ppm level.
level is just a quote from that source. There is no way that we can
define it as 'optimum'. The other thing that you should take away from
that article is that the malt contributes 100% of the Ca and Mg that the
yeast need for their fermentation. Adding any more of those ions via
the water is at the brewer's discretion and should be made based on
their goals. For instance, if you wanted the beer to clear rapidly, then
do add Ca. If you want more Cl or SO4, then the brewer might consider
more of a salt that contains Ca or Mg to supply those anions for flavor.
I wouldn't worry too much about the Mg:Ca ratio, but it is
important to recognize that you may not want to add a boatload of Ca to
your brewing water and push that ratio into an unfavorable range. You
should recognize that the additions of Mg and Ca to the water are
typically going to be modest in comparison to the concentrations of
those ions added by the malt. So as long as you aren't overdoing mineral
additions in the water, your wort is probably going to be in an OK
range.
Regarding starter preparation, yes it may be reasonable
to add a Mg salt to the water. I suggested that in the article as a way
to help infuse the yeast with a little extra Mg for the main ferment.
However, I suggest that you might best prepare your yeast by generally
mimicking the water profile that you will be brewing that next batch
with. I wouldn't worry too much about it though.
Let me correct
your take home message! Ca additions for the mash ARE beneficial since
they help precipitate oxalate from the wort. I suggest that all brewers
always include at least 40 ppm Ca in the mash for that purpose. But that
does not mean that your overall Ca content in the kettle needs to be
that high. For my recent lagers, I've been adding Ca salts to the mash
and none to the sparging water in order to end up with low Ca content in
the kettle. So target at least 40 ppm Ca in the mash and whatever you
want in the kettle (may be higher or lower). By the way, the latest
supporter's version of Bru'n Water includes a setting so that you can
tell the program that you want to add all the sparging minerals to the
mash to create the technique I mention above. The program also reports
the ion levels in the mash and kettle separately so that you can assess
that you are boosting that Ca level to that desirable 40+ ppm level.