Verdant yeast not attenuating anymore like normal

[beervoid]

Hello everyone,
I've been brewing with Verdant yeast since it got released and always got nice attennuation, somewhere between 72-78 usually.
Just recently, I'd say a month or 2 ago, I've not been getting very poor attenuation.
I'm doing everything exactly the same, same recipe that's I've been brewing for a long time. Always finishing around 1.017-1.019

Now I can't get the Verdant to attenuate more lower then 1.024. I calculated about 58-62% attenuation on the past few beers.
So I decided to mash lower 148f, even add more sugar to help dry it out up to 5% and the beer still does NOT want to go below 1.024.

Does anyone have any similar experiences? I'm left scratching my head what is going on.
I've heard Verdant had some problems with diastaticus but that should be fixed. My packages are good till 2024. All I can think of is the cell count went down in the packages or something.

 

[Erik the Anglophile]

I brewed with Verdant just a few weeks ago, a brown ale went from 1.044 to 1.009, with 8% of the grist as invert sugar.
Are you sure your thermometer is still accurate? I had a thermometer that started going off so my mashes were warmer than I thought leading to poor attenuation.

 

[beervoid]

I brewed with Verdant just a few weeks ago, a brown ale went from 1.044 to 1.009, with 8% of the grist as invert sugar.
Are you sure your thermometer is still accurate? I had a thermometer that started going off so my mashes were warmer than I thought leading to poor attenuation.

Thermometer is calibrated.

I used to mash at 156f or even higher with no sugar, now I added sugar and mashed in at 148f so I should have seen some kind of difference one would think?

 

[DBhomebrew]

the beer still does NOT want to go below 1.024

Have you recently switched to using a refractometer?

 

[BrewnWKopperKat]

For a next batch, a "forced ferment" test with Verdant and a couple of other strains of yeast would be interesting. Perhaps Nottingham and Windsor (as it don't utilize maltotriose).

 

[beervoid]

I brew other beers as well none of them are seeing attenuation problems and they use different yeasts, so im pretty sure this not equipment related

 

[beervoid]

For a next batch, a "forced ferment" test with Verdant and a couple of other strains of yeast would be interesting. Perhaps Nottingham and Windsor (as it don't utilize maltotriose).

In fact I just did a ale split batch with verdant and windsor a week ago.
Verdant finished at 1.024, Windsor finished at 1.026
I mashed high on that one, around 158f

 

[BrewnWKopperKat]

@beervoid : I checked my brewing notes for this year. All my Verdant batches were either Briess or Muntons DME recipes (90%-ish DME, 10%-ish sugar, small amount of steeping grains). FG ended up in the expected range.

---

Question: does any one have information on Lallemand's "Standard Conditions Wort"? It's mentioned in their product information sheets, but I couldn't find a definition.

 

[beervoid]

@beervoid : I checked my brewing notes for this year. All my Verdant batches were either Briess or Muntons DME recipes (90%-ish DME, 10%-ish sugar, small amount of steeping grains). FG ended up in the expected range.

---

Question: does any one have information on Lallemand's "Standard Conditions Wort"? It's mentioned in their product information sheets, but I couldn't find a definition.

Hi thanks for checking.
Im going through all my batches now as well and its been very consistent. Its cause its such a drastic difference out of the blue im digging what happened but cant find anything.

No idea about standard wort

 

[skroz]

Just ran across this thread while diagnosing my own issues with Verdant-fermented beers. Any luck?

I don't see issues with paler beers (<10 EBC), but the darker beers (>50 EBC) are all stalling in the mid to high 1.020s. I have solid data for three of these dark beers, with continuous data from a Tilt during fermentation and FG readings taken with both a hydrometer and EasyDens. All three started out with strong fermentation, but abruptly stopped and flocced out 10-15 points above the expected FG. Raising fermentation temperature at this point and rousing the yeast did not appear to make any difference beyond a point or two.

I plan to brew the same recipe and ferment with US-05 in a few weeks just to rule out the Verdant as the cause of the issues.

 

[Joshua Hughes]

Last 3 brews and all finished under 1.010. Drinking them now

 

[ebbelwoi]

My last few Verdant brews (APAs and Ambers, with various grain bill adjustments) had attenuations of 74%, (10/22, dry), 78% (6/22, repitch w/starter), 73% (4/22 repitch w/starter), 77% (3/22, repitch w/starter), and 74% (2/22, dry).

Having dug all that up, I realize that it's probably not useful to you except for the most recent batch.

 

[beervoid]

I think I found the culprit. I have been pitching and fermenting lower, so I probably got less initial growth.

 

[Miraculix]

I think I found the culprit. I have been pitching and fermenting lower, so I probably got less initial growth.

How low did you go?

 

[beervoid]

How low did you go?

Pitch at 16c and keep it at 16c its in a controlled fridge so internel temp probably higher. I got much less blowoff this way but also less attuation

 

[Miraculix]

Pitch at 16c and keep it at 16c its in a controlled fridge so internel temp probably higher. I got much less blowoff this way but also less attuation

I think I always stayed above 18c. Probably around 20 for most of the time.

 

[skroz]

Interesting. Here's data for my last four verdant pitches. The last two are nearly identical recipes, just with a higher temperature and pitch rate. It's actually still going, so I may end up with another point or two.

Batch	Color (EBC)	Pitch Temp	Ferm Temp	VDK Rest	Attenuation	Pitch Rate
1​	93​	17​	19​	22​	68%​	0.72​
2​	11​	17​	19​	22​	79%​	0.76​
3​	74​	17​	19​	22​	67%​	0.67​
4​	74​	17​	21​	24​	69%​	1.01​

 

[beervoid]

Interesting. Here's data for my last four verdant pitches. The last two are nearly identical recipes, just with a higher temperature and pitch rate. It's actually still going, so I may end up with another point or two.

Batch	Color (EBC)	Pitch Temp	Ferm Temp	VDK Rest	Attenuation	Pitch Rate
1​	93​	17​	19​	22​	68%​	0.72​
2​	11​	17​	19​	22​	79%​	0.76​
3​	74​	17​	19​	22​	67%​	0.67​
4​	74​	17​	21​	24​	69%​	1.01​

Try pitching at 21-23c then cooling to 16-18c.
I've just started doing this again and first batch had better attenuation.

 

[duncan_disorderly]

Interesting. Here's data for my last four verdant pitches. The last two are nearly identical recipes, just with a higher temperature and pitch rate. It's actually still going, so I may end up with another point or two.

Batch	Color (EBC)	Pitch Temp	Ferm Temp	VDK Rest	Attenuation	Pitch Rate
1​	93​	17​	19​	22​	68%​	0.72​
2​	11​	17​	19​	22​	79%​	0.76​
3​	74​	17​	19​	22​	67%​	0.67​
4​	74​	17​	21​	24​	69%​	1.01​

79% attenuation with 11 EBC beer. 67-69% with 74/93 end beers.

Is it the roast grains bringing attenuation down?

 

[skroz]

79% attenuation with 11 EBC beer. 67-69% with 74/93 end beers.

Is it the roast grains bringing attenuation down?

That's my current working hypothesis. All three dark beers had Carafa Special III at 2.5-3%, but the grist for #1 also had 10% roasted barley. #3 and #4 were the same black IPA with 2.5% DRC and 5% midnight wheat along with the carafa.

I would expect some reduction in attenuation from all those roasted grains, but not 10-12%. And I don't see this issue with similar recipes fermented with other yeasts. The higher pitch rate and fermentation temperature for the fourth beer seems to have helped a little, but something is still wrong.

So like I said above, I'm going to brew the same recipe from #3 and #4 again, but ferment with US-05. If that batch ferments normally then I think I can conclusively point the finger at Verdant (or at least that Verdant is being impacted by something else in the recipe.)

 

[duncan_disorderly]

That's my current working hypothesis. All three dark beers had Carafa Special III at 2.5-3%, but the grist for #1 also had 10% roasted barley. #3 and #4 were the same black IPA with 2.5% DRC and 5% midnight wheat along with the carafa.

I would expect some reduction in attenuation from all those roasted grains, but not 10-12%. And I don't see this issue with similar recipes fermented with other yeasts. The higher pitch rate and fermentation temperature for the fourth beer seems to have helped a little, but something is still wrong.

So like I said above, I'm going to brew the same recipe from #3 and #4 again, but ferment with US-05. If that batch ferments normally then I think I can conclusively point the finger at Verdant (or at least that Verdant is being impacted by something else in the recipe.)

The roast grains will affect the mash pH if they go in from the start. Possibly a factor!

Is it a fresh pack pitched every time? Did you buy several at once? Could they have been badly treated before you bought them? I've used Verdant quite a few times and had mid 70s every time. I do dark beers as well as pale but I add the roast grains half way through the mash. Soft water.

 

[skroz]

The roast grains will affect the mash pH if they go in from the start. Possibly a factor!

Is it a fresh pack pitched every time? Did you buy several at once? Could they have been badly treated before you bought them? I've used Verdant quite a few times and had mid 70s every time. I do dark beers as well as pale but I add the roast grains half way through the mash. Soft water.

I considered mash pH and took a few extra measurements for the last two batches. Mash pH was a little low for a dark beer, but not terrible. I tested and calibrated the pH meter after the fourth beer just in case... it was accurate within 0.03 in 4.01 pH standard solution.

Batch	Strike pH	Mash pH	1st run. pH	Post Boil pH
3	8.58	5.28	5.19	5.09
4	8.58	5.29	5.18	5.13

Fresh packs were pitched: 2x for #3 and 3x for #4. I don't recall the dates on the packets, but they were not all the same. I think the 5 packs were from 3x purchases, but it could have been only two. I do tend to choose the oldest packets first, so #3 would have been slightly older yeast, and the two beers were brewed two weeks apart. All packages were stored in my fridge, but of course I can't say how they were handled before they reached me.

Both were 27 L into the fermenter and oxygenated with 1/4 L O2 per minute for 3m 30s. Both showed fermentation activity within 12H and were fermenting vigorously after 24 (#4 was down 20 points, at least according to the tilt, after 24 hours. I take the actual measurement with a grain of salt, but I trust the tilt to give an accurate fermentation rate.)

I can't say yeast viability definitely wasn't the issue, but I don't think so. I'd have expected a longer lag time or sluggish start with poorly treated or old yeast, and there was no evidence for either beer.