WLP500 Flavor

[mediant]

You conveniently skipped the part about zinc being toxic in low levels (0.6ppm) without adequate manganese present. Do you recommend to supplement manganese too?


Sure, we can ask Martin why he says zinc is toxic at 1ppm...

Any thoughts on Kai's experiment?
http://braukaiser.com/blog/blog/2012/06/22/the-effect-of-zinc-on-fermentation-performance/
He references a text stating zinc is toxic at 0.6ppm. However his experiment seems to show no effect by changing the zinc concentration.

Why all the conflicting information?


I'm still a little skeptical, but all right.

Look, I don't want to be pushy over this Zinc supplement issue, simply looking for answers just like you.
As I understand it, the whole toxicity thing stems from 1977 research, which investigates the effect of demineralised wort on yeast performance. Control untreated wort had 0.14 ppm Mn, which kind of makes the whole toxicity thing rather theoretical, at least for all-malt worts, as only 0.1 ppm Mn was found to be enough.
Forgot to mention that Handbook of Brewing Kai is referring to quotes the same research with same conclusions - 0.6 ppm Zn toxic only when Mn is below 0.1 ppm.

I'll grab some Wyeast nutrient next chance I get.

I'm going to try something different - next time I'll collect spent yeast from some low hopped hefe/belgian batch, and will add a spoonful at whirlpool to provide amino acids, along with some diluted Zinc Sulphate Heptahydrate to the fermenter.

 

[Big Monk]

+1 on lower aeration, this goes without saying for esters. I noticed that Stan Hieronymus mentions lower pitch rates being used by Belgian breweries in his book and the article, any thoughts?

If you look at the breweries using very low (by generally accepted standards) pitch rates, Duvel and Rochefort come instantly to mind, you see that they have incredibly healthy, active yeast. Rochefort in particular uses a form of Drauflassen whereby they brew a single beer per week with multiple batches filling the fermenter. On successive brewdays they add the fresh batch to the previous day's batch with additional yeast.

I have experimented with under-pitching before and while i have personally had success, as have others, pitching more cells is probably much closer to what most people do. Underpitching is more likely to turn out bad then slightly overpitching.

 

[Big Monk]

BTW, if anything, nutrient blends containing zinc and amino acids stimulate ester production.

You always want to remember to account for Sulfate with a nutrient blend as well. Since the medium for Zinc, Magnesium, and Manganese is most often Zinc Sulfate, Magnesium Sulfate, and Manganese Sulfate, you have the potential to add non-trivial amounts of sulfate to the finished profile.

Just food for thought.

 

[Big Monk]

You conveniently skipped the part about zinc being toxic in low levels (0.6ppm) without adequate manganese present. Do you recommend to supplement manganese too?

I know that many of the common nutrients supplement Zinc, Magnesium, Manganese, Sulfate, and Potassium.

For Wyeast Nutrient, you can expect Zn, Mg, Mn, and SO4 as the major players. For their recommended dose:

Dose Rate = 0.116 g/l (0.439 g/gal)

Magnesium (ppm) = 0.928
Sulfate (ppm) = 13.92
Zinc (ppm) = 0.635
Manganese (ppm) = 0.567

If you want to change the dose rate, you can expect the following change in minerals:

Magnesium (ppm) = 0.928 * ( New Dose Rate / Stock Dose Rate )
Sulfate (ppm) = 13.92 * ( New Dose Rate / Stock Dose Rate )
Zinc (ppm) = 0.635 * ( New Dose Rate / Stock Dose Rate )
Manganese ppm) = 0.567 * ( New Dose Rate / Stock Dose Rate )

For Fermax, you can expect Zn, Mg, Mn, K, and SO4 as the major players. Their recommended dose is very high, but if we change it to give comparable Zinc values to Wyeast:

Dose Rate = 0.322 g/l (1.219 g/gal)

Potassium (ppm) = 57.86*
Magnesium (ppm) = 3.178*
Sulfate (ppm) = 13.72*
Zinc (ppm) = 0.632*
Manganese (ppm) = 0.117*

*These values are based on the %'s of constituent parts and my assumption (a good one IMO) that my mg values for each mineral part is correct. Fermax is 40% by Weight Dipotassium Phosphate, 10% Magnesium Sulfate, and 10% Yeastade 50 (of which 5% is Zinc Sulfate and 1% is Manganese Sulfate).

To allow free rise I should put the temp probe in a jar of water in my fermentation fridge?

Take it out of the fridge!

 

[Big Monk]

...diluted Zinc Sulphate Heptahydrate to the fermenter.

If my math is correct, 0.1 g of ZnSO4 Heptahydrate into 18.93 l gives:

Zinc (ppm) = 1.164
Sulfate (ppm) = 1.765

 

[mediant]

If you look at the breweries using very low (by generally accepted standards) pitch rates, Duvel and Rochefort come instantly to mind, you see that they have incredibly healthy, active yeast. Rochefort in particular uses a form of Drauflassen whereby they brew a single beer per week with multiple batches filling the fermenter. On successive brewdays they add the fresh batch to the previous day's batch with additional yeast.

Ah, that explains a lot! Drauflassen with non-aerated wort is very powerful ester producer, although it also stimulates yeast growth if I'm not mistaken...

I have experimented with under-pitching before and while i have personally had success, as have others, pitching more cells is probably much closer to what most people do. Underpitching is more likely to turn out bad then slightly overpitching.

That's perfectly acceptable approach. On the other hand, I've seen Lallemand recommends to pitch half of regular rate for their Munich dry yeast to increase isoamyl acetate. There's no consensus in scientific literature either, as it seems to be strain specific, so healthy pitch may be a safest bet.

 

[Big Monk]

Ah, that explains a lot! Drauflassen with non-aerated wort is very powerful ester producer, although it also stimulates yeast growth if I'm not mistaken...
That's perfectly acceptable approach. On the other hand, I've seen Lallemand recommends to pitch half of regular rate for their Munich dry yeast to increase isoamyl acetate. There's no consensus in scientific literature either, as it seems to be strain specific, so healthy pitch may be a safest bet.

I take liberties with 3787 because it's my "house" yeast. I know it well.

 

[mediant]

I recently brewed a tripel with WLP500 (Chimay).

Early in fermentation, tasting revealed an incredible amount of cherry and plum flavor and aroma. When it finished fermenting, the dark fruit flavor had faded almost entirely, leaving a relatively clean, somewhat tart, very low phenol, beer with some banana.

Something just crossed my mind while I browsed through my notes. I've experienced similar issue with two last Hefe batches, while ones before that were fine. A notable difference I see is the last batches were not cold crashed immediately (ones before were on 4th-5th day since pitch). I wonder if residual yeast esterase activity may be coming into play here, so it's critical to take the beer off yeast ASAP to preserve these esters?

Do you chill or cold crash after fermentation? For how long was your beer fermenting?

 

[Big Monk]

Something just crossed my mind while I browsed through my notes. I've experienced similar issue with two last Hefe batches, while ones before that were fine. A notable difference I see is the last batches were not cold crashed immediately (ones before were on 4th-5th day since pitch). I wonder if residual yeast esterase activity may be coming into play here, so it's critical to take the beer off yeast ASAP to preserve these esters?

Do you chill or cold crash after fermentation? For how long was your beer fermenting?

Interesting observation.

If we go to BLAM and read about the Trappist breweries and how they handle the beer after primary fermentation is completed, we see:

Chimay - Centrifuges after primary fermentation and holds the beer at 32 F for 3 days.

 

[RPh_Guy]

Zinc Sulphate Heptahydrate to the fermenter.

19L batch?

0.15mg/L * 287.53 g/mol / 65.38 g/mol * 19L / 1000mg/g =
0.013g to achieve 0.15ppm zinc.
Time for a stock solution!

If you look at the breweries using very low (by generally accepted standards) pitch rates, Duvel and Rochefort come instantly to mind, you see that they have incredibly healthy, active yeast.

In my mind, this is exactly what a vitality starter achieves. The yeast are at peak performance when pitched -- not exposed to alcohol, tired from fermenting, or dormant from cold crashing.

The article from BYO said other Trappist breweries underpitch as well.

Take it out of the fridge!

The fridge is in my garage. Ambient in my garage can range from ~20°F - 100°F depending on the time of year. I think I need some kind of control?

On the other hand, I've seen Lallemand recommends to pitch half of regular rate for their Munich dry yeast to increase isoamyl acetate.

I've been extremely successful underpitching (no starter, ~0.25M/mL/°P) WLP300 Hefeweizen with a tailored temperature schedule.
Conversely, I've overpitched WLP300 and it led to a clean profile almost like american ale yeast -- practically no esters or phenols.

Do you chill or cold crash after fermentation? For how long was your beer fermenting?

No cold crashing but I did leave it for maybe 3-4 days after it finished. Because I bottle condition, extended yeast contact is inevitable. I don't think that's a problem.
Tasting it would be an easy way to be sure.

 

[Big Monk]

I don’t control temp at all. I just measure wort temp in the center with a thermowell for reference.

If you are concerned with low ambient temps dropping wort temp low, either bring it inside or devise a way to just heat the wort if necessary.

 

[RPh_Guy]

I don’t control temp at all. I just measure wort temp in the center with a thermowell for reference.

If you are concerned with low ambient temps dropping wort temp low, either bring it inside or devise a way to just heat the wort if necessary.

Hm.. I could keep it at ~68°F ambient in my basement. Think that's OK?

 

[Big Monk]

Hm.. I could keep it at ~68°F ambient in my basement. Think that's OK?

I would imagine you could ge by with that. If you are worried, pitch around 62 ish and just let it go naturally.

I bet you don’t see a significant increase until about 36 hours in. If you get 24-36 hours in the mid 60s and then another 12 before you hit 70, you should be good to go.

 

[mediant]

Interesting observation.

If we go to BLAM and read about the Trappist breweries and how they handle the beer after primary fermentation is completed, we see:

Chimay - Centrifuges after primary fermentation and holds the beer at 32 F for 3 days.

Yup, all the other breweries mentioned in the book too. Check out this - https://limo.libis.be/primo-explore...rias&tab=default_tab&lang=en_US&fromSitemap=1

The study is performed after maturation for one week at -1C (30F). My take is without cold maturation much more yeast is passed into the bottle, so the ester breakdown is going to be much more rapid.

BTW, it may be not coincidental that Germans use lager yeast to bottle carbonate Weissbier...