Zinc usage - amount for healthy fermentation

[mashdar]

Wyeast beer nutrient blend. It has everything a growing yeastie needs. Including zinc.

If Chris White is to be believed, the zinc gets captured by break proteins, and needs to be added direct to fermenter.

Makes me wonder if gunk in the fermenter is good for the yeast, and maybe even removes the need for zinc supplements. (The grain has plenty, if it makes it to the yeast.)

I add the wyeast supplement direct to fernenter occasionally.

 

[scrap iron]

Wyeast beer nutrient blend. It has everything a growing yeastie needs. Including zinc.

I have always used this product and have had good results but I've used it the BK. I usually boil it in a small amount of water the night before. After reading threads about zinc I'm wondering if it would work better to add it to the fermenter. This due to it possibly being bound up in the BK trub. If so I would just boil it before adding to the fermenter.
comments?

 

[MaxStout]

I add it to the BK, about 10-15 minutes before knockout.

 

[stamandster]

STAM ypu said A few Whitelab articles also discuss Zinc additions @ 0.20ppm per 5 gallons.

you can't have ppm per gallons ppm is absolute

Maybe you increase concentration with volume ; )

I meant to adjust "for" 5 gallons and with their product. Regarding ppm, convert as you need and as explained

 

[cactusgarrett]

The approach in the past has been to add zinc to the kettle, but recent work (within the past... year or two?) has suggested/shown that a huge portion gets tied up in trub, so the best way to make it available for yeast is directly to the fermenter during knock out.

 

[stamandster]

Couldn't you just increase ppm so as to account for trub loss?

 

[cactusgarrett]

Couldn't you just increase ppm so as to account for trub loss?

But that's the rub, at such a small amount already, there's no practical way to determine how much is getting tied up and how much is actually making it over to the FV, espcially with varying grainbills likely making that a dynamic amount. Why not just put it into the FV to begin with to remove that variable?

For example:

 

[stamandster]

Yeah, I suppose that's true. I mean the recommended amount is between 0.15 and .5ppm, so there's definitely a healthy buffer.

 

[bobtheUKbrewer2]

I meant to adjust "for" 5 gallons and with their product. Regarding ppm, convert as you need and as explained

2 ppm in 1 ml or 9000 litres is the same concentration -

 

[mac_1103]

2 ppm in 1 ml or 9000 litres is the same concentration

but 9 million times the mass

 

[stamandster]

2 ppm in 1 ml or 9000 litres is the same concentration -

Not sure why you are harping on this. Unfortunately, I can't adjust my initial post to remove all confusion and no longer have this "issue".

 

[bobtheUKbrewer2]

I just chuck in approx 10 ml AMS per approx 23 litres - it is not that critical, neither is Zn concentration - early merry xmas....

 

[Miraculix]

If Chris White is to be believed, the zinc gets captured by break proteins, and needs to be added direct to fermenter.

Makes me wonder if gunk in the fermenter is good for the yeast, and maybe even removes the need for zinc supplements. (The grain has plenty, if it makes it to the yeast.)

I add the wyeast supplement direct to fernenter occasionally.

The trub in the wort is actually good for yeast health. It contains a lot of things that the yeast needs, including the zinc. The downside is, it also includes a lot of things that can make a beer go stale sooner amongst other negative impacts on the flavour and shelve life.

It contains a lot of proteins. If the yeast gets somehow "tangled up" in these proteins, the yeast can produce enzymes that chop these proteins into pieces. Unfortunately this also chops the foam enhancing proteins into pieces, so an excess in trub can lead to a decreased head retention.

I've brewed many bad and many great beers with and without the trub in the fermenter.

So basically... I don't know?

 

[cactusgarrett]

it is not that critical, neither is Zn concentration

Quite the contrary. If you overshoot and add too much zinc, it's actually toxic to yeast and has effects completely opposite of why you're adding it in the first place. You'll know that you've gone overboard by the yeast/trub turning into a gooey/pastey mess at the bottom of the FV.

 

[505-Brewer]

For 15 gallons of wort. Woof.
I'll stick with the Ionic Zinc...

Cheers!

Agreed.

 

[JJFlash]

Couldn't you just increase ppm so as to account for trub loss?

That is exactly what Wyeast Nutrient does.
At 2.2 grams per 5 gallons it adds 0.635 ppm zinc.
The majority is in trub loss never making it to the fermenter where it is really needed.
Direct application to fermenter allows more precise control.

 

[bobtheUKbrewer2]

I meant +/- say 1% of target addition

 

[DuncB]

I'm using 40mg Zinc gluconate tablets, these have 15mg of zinc available.
So half a crushed tablet in boiled water added into the fermenter.
Batch size for me is 23 litres.
Seems to be working okay, I've also started adding the yeast nutrients post boil.

 

[IslandLizard]

I'm using 40mg Zinc gluconate tablets,

I ran out of Zinc Chloride ages ago, and started to use Zinc Gluconate as a substitute.

Then a member here claimed that the Gluconate form is not one yeast can assimilate.
He used one of those pricey "droppers" from Amazon. and swore by it.

 

[mac_1103]

He used one of those pricey "droppers" from Amazon.

Doesn't the pricey dropper work out to something like six cents a batch?

 

[stamandster]

I found an article on the Zinc Gluconate https://braukaiser.com/blog/blog/2012/06/22/the-effect-of-zinc-on-fermentation-performance/

 

[mashdar]

a

I found an article on the Zinc Gluconate https://braukaiser.com/blog/blog/2012/06/22/the-effect-of-zinc-on-fermentation-performance/

One of the comments referenced this paper https://www.tandfonline.com/doi/pdf/10.1094/ASBCJ-57-0129
Tantalizing name! The comment seemed to suggest the paper found trub-bound yeast is available to yeast.

edit: Here's a different paper not behind a paywall https://themodernbrewhouse.com/wp-content/uploads/2017/04/kuehbeck_0406.pdf

 

[stamandster]

I thought this was interesting too regarding zinc link with glutathione usage https://academic.oup.com/femsyr/article/17/4/fox028/3821179

 

[oldschool]

Instead of necro'ing an almost ten year old thread, I thought I'd spin up a new one regarding zinc usage for healthy fermentation for anyone doing math for themselves.

Recent generally accepted sweet spot for elemental zinc seems to be 0.3 ppm into the fermenter (that is 0.3 mg zinc per 1 L wort). However, this gets convoluted a bit since you need to take into account your form of zinc (ex. heptahydrate, monohydrate, etc.). For this purpose, I'm examing the heptahydrate (because that's what I have on hand). There's 22.8% elemental Zn in ZnSO4*7H2O (heptahydrate), so the info in the OP of that other thread would actually yield about 0.114 ppm elemental zinc instead of what they thought was a 0.5 ppm target.

The OPs prep matches closely with what BSG recommends on the low end (0.5-1.0g per 10 HL => 0.5-1.0 ppm), translating to 0.114-0.228 ppm elemental zinc.

I crunched numbers for my own purposes (6.5 gal into fermenter) and what I'd need to prepare and perform:

• Stock Solution: 494 mg into 100 mL water
• Working Solution: 5.0 mL of stock solution into 6.5 gal wort => 0.228 ppm

(obligatory "show my work" and imperial/metric conversion section)
5.0 mL x 4940 mg/L x 1L/1000mL x 22.8% ÷ 6.5 gal x 1 gal/3.8 L = 0.228 mg/L (ppm)

Obviously your preferences and targets will vary.

I’m also using zinc similarly but I’m not sure your calculations make sense to me.

Regardless I make a 1% solution of zinc sulfate heptahydrate and add this to the kettle during whirlpool.
I target .35-.4ppm in the hot wort since I read that a lot is lost to trub.
Some day I’ll send wort samples out for Zn testing but haven’t gotten that far yet.

 

[cactusgarrett]

I target .35-.4ppm in the hot wort since I read that a lot is lost to trub.

That's my point throughout this thread - the amount needed vs toxic to the yeast is somewhat a fine line, espeically at those super low levels. "A lot lost to trub" can be variable and unknown, so the more reliable process is to add to the FV. This shift in process is evident with pro brewers in the past year + also.

 

[oldschool]

That's my point throughout this thread - the amount needed vs toxic to the yeast is somewhat a fine line, espeically at those super low levels. "A lot lost to trub" can be variable and unknown, so the more reliable process is to add to the FV. This shift in process is evident with pro brewers in the past year + also.

Agreed but I don’t like the idea of adding the solution to cold wort as-is because things certainly grow in it while in the fridge, and I don’t want to sanitize it. Maybe it doesn’t even matter

 

[mac_1103]

Agreed but I don’t like the idea of adding the solution to cold wort as-is because things certainly grow in it while in the fridge, and I don’t want to sanitize it. Maybe it doesn’t even matter

If you're really paranoid you could add the zinc to a cup of wort and heat it back to ~170F for few minutes before adding it back to the fermenter. Or just bring a cup of water to a boil, add the zinc and let it cool while you're chilling and transferring the wort, and then dump that into the fermenter.

 

[cactusgarrett]

Agreed but I don’t like the idea of adding the solution to cold wort as-is because things certainly grow in it while in the fridge, and I don’t want to sanitize it. Maybe it doesn’t even matter

Mine's stored on the benchtop, actually. This wasn't stated in the original post, but basic sanitization practices should help with this. For me, the issue you commented on was easily addressable:

I boiled water, let it cool, then made the Zn stock solution from that (obviously sanitizing all equipment and glassware). pH adjustment helps to prevent growth, also while keeping the Zn in solution.

 

[z-bob]

So has anyone tried just adding a zinc anode to the kettle or fermenter? You wouldn't have any real control over how much zinc is absorbed, but it shouldn't be zero. The problem would be maybe too much zinc.

I was going to try making some lime-sulfur to strip the copper off of some pennies last time Wife was out of town so I could try it, but I forgot. (I don't dare do that when she's home because of the smell)

 

[oldschool]

Mine's stored on the benchtop, actually. This wasn't stated in the original post, but basic sanitization practices should help with this. For me, the issue you commented on was easily addressable:

I boiled water, let it cool, then made the Zn stock solution from that (obviously sanitizing all equipment and glassware). pH adjustment helps to prevent growth, also while keeping the Zn in solution.

What pH do you acidify to?

 

[JJFlash]

What pH do you acidify to?

pH 4.0 is most common recommendation.

 

[cactusgarrett]

What pH do you acidify to?

4.0

 

[oldschool]

pH 4.0 is most common recommendation.

most common for what?

 

[oldschool]

4.0

why does lowering the pH keep the zinc in solution? If just going by appearance, I don’t have any solubility issues whenever I mix mine up with RO water.
reducing the pH for microbial stability makes total sense though.

 

[mashdar]

why does lowering the pH keep the zinc in solution? If just going by appearance, I don’t have any solubility issues whenever I mix mine up with RO water.
reducing the pH for microbial stability makes total sense though.

White labs uses pH 4.0.

Here's a paper that appears to show good solubility at pH 4, but I must admit I don't know what "lg" means.

edit: forgot link
https://www.researchgate.net/figure/Solubility-of-ZnO-as-function-of-pH-at-25_fig6_226563589

 

[bruce_the_loon]

why does lowering the pH keep the zinc in solution? If just going by appearance, I don’t have any solubility issues whenever I mix mine up with RO water.
reducing the pH for microbial stability makes total sense though.

It is because at neutral or basic pH, there is an excess of OH¯ (hydroxide) ions that readily react with Zinc to form insoluble Zn(OH)² that precipitates out. An acidic pH keeps that from happening too much.

 

[DavidWood2115]

Here's a paper that appears to show good solubility at pH 4, but I must admit I don't know what "lg" means.

lg usually refers to log_10, or base 10 logarithm. pH is defined as the negative base 10 logarithm of the concentration of hydrogen ions (aka protons).

 

[mashdar]

lg usually refers to log_10, or base 10 logarithm. pH is defined as the negative base 10 logarithm of the concentration of hydrogen ions (aka protons).

"lg" was on the zinc concentration, but that explains the odd axis values.

Abbreviating "log" as "lg" strikes me as really stupid. One man's opinion.

 

[MaxStout]

Just to keep the pedant party going, that could be a 1. They used a font where numeral 1 looks identical to a lower-case L.
So 1g?

 

[mac_1103]

The integers on the y axis strongly suggest that it's a log scale.