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You are here: Home --> Forum Home --> Brewing Forum --> Brewing Discussion --> Anyone check out the March/April Zymurgy water article

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ingoogni
nl
314 Posts


Health shops have 50 mg pills of zinc-citrate.

on the Mg Ca subject, there is quite some literature and also quite a bit with impractical additions of 500 mg Mg and 800 mg Ca per liter. Looks like most conclusions are based on these additions. A normal mash has already more Mg than Ca so Martins advise to add Ca only at the (beginning of the mash) seems sound. I'll change my procedure somewhat and see if there are noticeable changes.

Adding Mg to starter is quite interesting, have to do some reading to find the right amounts. Probably just add until pH 5 - 4.7




Posted 34 days ago.

vinpaysdoc
Charter Member
High Point, NC
321 Posts


Thanks for the links. Looks like I need to get something with Zinc in it to add to the starters. Do you add Zinc-citrate? If so, what amount?






Posted 34 days ago.

ingoogni
nl
314 Posts


I use the Wyeast nutrient with zinc. A normal addition is 0,15 - 0,3 mg/l zinc in your wort for a good fermentation, 3mg for 5 gallon, so you could add 3-6 mg to a starter.

Those Zinc supplement tabs are the easiest available form of zinc, they are zinc citrate or zinc gluconate, of the latter I'm not sure whether it works for the yeast. Zinc sulphate and  zinc chloride are widely used but less easily available.




Posted 34 days ago.

mchrispen
Bastrop, TX
485 Posts


So both the usual subscription and the replacement copy I ordered arrived last night... I loved the article, but skeptical on a couple of points.

1. Context is important, and some of the conclusions that Martin draws from his article seem like a stretch taken on their own merit. More on that later. I plan to go back through the article and highlight and draw lines to the contextual statements. It jumps a bit.
2. He clearly states and illustrates that normal wort composition has more than adequate Ca and Mg for yeast health. Additional Ca and Mg have direct impacts on wort composition (at least into the fermenter), fermentation lag times and attenuation, as well as byproducts like beer stone. I didn't notice anything commenting on beer stability or longevity - which Narsiss and others speculate - but there are alleged benefits from removing trub during transfer to fermenter. (yeah I know Marshall experimented with this - but it is fairly well established at the commercial level).
3. The yeast starter experiment was done in a sucrose solution - not in traditional wort. Certainly worthy of experimentation and I may give that a shot (yeah blog idea!) The implication of additional Mg helping to create biomass is clear.
4. The correlation of a Ca to Mg ratio is confusing, but there seems to be a counter effect of too much Ca in a starter. Creating a situation with more Mg than Ca at 1.8:1 will take some very careful measurement. I am not sure how they draw that conclusion - the paper is a bit vague (or I missed that part) on experiments and results showing elevated Ca... it seems that in all cases the Ca was drawn from calcium chloride and I wonder what the role that may have played in addition to Mg. Magnesium Chloride is one of the saltiest and intensely minerally flavored addition - so dosing the correct amounts may also require some adjustment at mashing (particularly with very large lager yeast pitches) given the levels in malt.
5. The linked research also seems focused on lager yeasts, which have different metabolism rates and behaviors than ale yeasts. I am hesitant to draw a conclusion for any standard ale starters... but perhaps looking at regional appellation makes some sense. There are some ales that are brewed with very soft water - and perhaps that may require some additional Mg to boost healthy fermentation.
6. No data seemed to point toward the issue of viability and mutation. But the mineral levels seem nominal so I doubt that there are stress vectors introduced if you keep the calculated liquor concentrations of Ca reasonable and the Mg below 40 ppm in any scenario (mash tun, kettle or starter).

Maybe I overreacted to the conclusions... but find these confusing:
1. Don't add excess calcium in pursuit of improved enzyme activity. - this flies in the face of the application of calcium to lower mash pH to optimize enzyme activity. The comment on Ca v Mg in enzyme production early in the article makes this statement make more sense however.
2. Adding magnesium salts (Epson salt or magnesium chloride) to yeast starters to pre-condition yeast may improve fermentation performance. This seems a leap of faith - again the tests were in a sucrose only solution devoid of malt derived sugar compounds and nutrients. Reminds me of nutrient requirements for cider or mead where the trace minerals are not provided. I am concerned about the pre-condition statement and can only conclude he is again referring to yeast fermentation where Mg is utilized, but Ca can cause yeast to clump and floc out prematurely.

This seems a lot to balance out and digest against the practical expectation in the brewery... and to me, may indicate that reserving a larger portion of the mineral for the boil may make some sense (relative to enzymatic activity). It doesn't address any of the very iconic and success beers that have been brewed historically with extremely hard water. Curious.






Posted 34 days ago.

uberg33k
Charter Member
The Internet
314 Posts


You said you've worked with him before, right?  Couldn't you ask for some clarifications?



Posted 34 days ago.

mchrispen
Bastrop, TX
485 Posts


I have sent a note over... haven't heard from him on this or a problem jibing a mash estimate with the current free version and his beta version of the spreadsheet. I see that he is still posting on HBT and AHA forums and reached out again to him on Facebook and email this morning.

Like a lot of research - I suspect that it isn't exhaustive enough to reach a conclusion - rather point to possible correlations that must be further explored. I'll update when I hear from him ... but maybe NHC till I can sit down and have a conversation.

One of the AHA research projects I proposed was to measure the effect of different mineral additions in isolation - to see their impact on mash pH over a 90 minute period, but also to determine solubility and the best method to add to a mash and compare to a baseline DI mash. This article will need to inform that set of experiments I think. Not going to do a full congress mash 8 times in a row, but think I can do a smaller volume mash as long as the water/grain ratios are consistent and I am absolutely rigid about the mineral additions. A comparison of all the single minerals to a standard IPA profile in an overlay may also inform the correct times to take mash pH measurements and set expectations for 2-3 measurements during mash and how they should change over time. Wondering if I can save lab samples and get AHA to run mass spec tests for me on the results.




Posted 34 days ago.

mchrispen
Bastrop, TX
485 Posts


So Martin didn't answer my direct questions - but did respond to queries over at the AHA forum.

www.homebrewersassociation.org/forum/...


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.





« Last Edit: March 18, 2015, 03:54:34 PM by mabrungard »






Posted 34 days ago.

uberg33k
Charter Member
The Internet
314 Posts


What he posts on the AHA forms seems a lot more straight forward.  It also addresses something I've wondered about, which is differentiating between mash and kettle ion additions.  There doesn't seem to be much guidance for what works in the kettle ... or even the fermenter or packaging, but it's a start.



Posted 34 days ago.

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