Starter OG = 1.040, 48 hrs later on stir plate FG = 1.040 .. WLP500

[smaro]

Hello all! A few days ago I set up a 1.040 starter using a 2 month old (1st gen, from the lab) vial of WLP500, assumed to be at about 55% viability. Set up the wort just like all starters before (2L solution w/ DME + DAP), got the temperatures right before pitching--at about 71F (+/- 1 degree) 2L flask. I dropped in 1 drop of foam control right before setting it on the stir plate.

I've used foam control (FC) before in a starter (again just a drop), although I added this after strong fermentation (was heading towards overflow) previously. This time was only different in that I added the FC upon flipping the stir-switch. After observing very periodically throughout a solid 36-48 hours on the stir plate, I was worried because a Krausen never formed, although it did look like there was some kind of activity--I didn't exactly see what I expected in terms of little bubbles rising to the top, but there was something that resembled tiny bits of DME--although this could very well have been the yeasties.

Well after shutting off the stir plate 48 hours in, after only a few minutes it appeared there was a nice thick slury layer of yeast cells already collecting at the bottom (much more than in the original vial). I didn't think much more of it and set it in the fridge to flocculate the rest out for the subsequent decant.

24 hours later I'm ready to split off this amount for 2 seperate upcoming brews. I decide to bust out the hydrometer and measure the decanted wort. 1.040.

Did I not leave it long enough on the plate?! As said, I assumed I had propagation/attenuation due to the large amount of slurry. I also assumed it was okay to not have a Krausen because of the foam control (seemingly acceptable after researching other posts).

Based on the information provided, anyone have any ideas..namely from experience with either this strand (my first time using WLP500) or this viability (~55%) or this type of usage (foam control in starter) or this type of observation (thick slurry on bottom w/ no Krausen).. etc etc...?!

Not panicking by any means, but would like to have an idea of what to do next.. I'm assuming whipping up another batch of wort and going at it again.. I mean the hydrometer doesn't lie. Hmmm.

Thanks in advance for any input on the matter!

 

[smaro]

Does that not look like a healthy slurry of yeast?

 

[mbobhat]

Apparently this is a slower starting yeast. I'd give it a couple more days especially since it is two months old

https://www.homebrewtalk.com/showthread.php?t=342415

 

[tenbricks]

That does look like a healthy yeast starter, not just a bunch of trub. I'd bet your FG measurement is off. Taste the liquid, you'll know right away if it has fermented or not.

WLP has always fermented very quickly for me, and I also put a drop of fermcap in each starter.

 

[smaro]

It tasted very sweet, indeed. :/

The FG reading was a conservative one, really it may have even been a couple points higher. I just can't explain how I got so much slurry.

If I add any more time on the stirplate (I'm whipping up another batch of wort at this very moment) I'll be encroaching on 3 days... 3 days on a stirplate--is that unusual? I'm going to forego the foam control this time, too... that is until Vesuvius decides to erupt (hopefully) this go around.

Still, so much slurry -- I really hope I'm not starting with too much yeast and overconcentrating.

Could this be clumped up DME by any chance--maybe bad/old sugar from the LHBS? So much slurry...

 

[DurtyChemist]

I don't know how you could read a hydrometer reading wrong from 1.040 to 1.01x. If I didn't see a gravity drop I would keep it on there.

 

[tenbricks]

If it tastes like wort, then you must be right, it hasn't done much of anything yet. Hmm.

I assume you boiled the solution before adding the yeast, right? It's normal to get a bunch of little chunks of hot break material in there afterwards, but not usually that much.

It's not unusual to see no kreusen especially with fermcap, but during active fermentation you can see small bubbles swirling up through the liquid - I just shine a flashlight into it.

All I can suggest at this point is to let it keep going. Shake it up a bunch to get more O2 in. Bump the temp up to 80's if possible, you don't care about off flavors in the starter and the yeasts are happier warmer. Maybe a bit more yeast nutrient.

Give it a few more days. If still nothing, the yeast must have been way below 55% viability. Maybe the vial was mishandled before you got it?

 

[smaro]

Thanks everyone for the input. No matter the outcome, I will be sure and post the results as the reason for posting is initially for solutions/advice... but ultimately posting helps educate the community. Here's how I decided to respond:

Because I was so confident that all was okay after taking it out of the fridge, I decanted the wort into a non-sterile cup before thinking to take the gravity measurement. At some point I also stuck my beardy face into the cup to take a sip to discover how sweet it remained--therefore I've decided to just dump the wort and start over with new DME (plus the slurry--which is hopefully yeast!). This go around I will wait to add foam control so to know exactly what is going on while on the stir-plate.

If it is indeed new fresh yeast (which doesn't explain the sweetness and super 1.040 FG) then I imagine it will come to life more quickly than before. Still, I'm not taking it off the starter this time without knowing for sure that expected attenuation has taken place. I have read of many differing cases with WLP500 as well as other strands in terms of a yes/no occurance of vigorous Krausen. We'll see.

To answer a previous question, yes the DME was boiled for 15 min with DAP yeast nutrient added in the last minute or so of the boil. Then cooled with ice bath down to about 71F (which is room temp here, and therefore the temp of the yeast in the vial), pitched to the starter, dropped in a bit of FC, then flipped the stirplate on.

Up to this point all WLP yeast strands I've used in the past have done exactly as expected in the yeast starter, Karusen w/in 24 hr and all.

When it comes to WLP yeast vials, when you order from either online sources or LHBS, how often do you end up with yeast around 50% viability? When it does happen, how often do these result in sluggish starts in starters w/ stir plates?

 

[smaro]

Here's the FG reading, just to remove any potential suspicion...

 

[smaro]

An update and follow up question...

First of all, alas the wort was unfermented and the yeasties had not began to dance. After only about 3-4 hours longer than I had it on the stir-plate before, I finally started to see classic yeast fermentation bubbles. I must have just taken it off the stir plate previously right when they were on the verge of getting going. Meh. As such, I wanted to point out that I never had to add foam control as throughout the (almost 1.5-2 days of) fermentation a Krausen never got going--just a small small amount of foam bubbles.

With that said, quick question... I mentioned previously that I decanted the wort that turned out to be unfermented, still sitting at 1.040 pts. Well even though I poured it into an unsanitzed glass and even dunked my beard into it (when I discovered it was still sweet), I went ahead and kept it without dumping it---put on a lid and stuck it in the fridge. This was about 4-5 days ago. So my question is, can I not just boil this a bit (maybe add some water to account for boil off) and use it for another yeast starter in the next couple of days? I can't see why not!

Anywho, thanks again to everyone who contributed info on this subject--your support and and advice is always much appreciated!

 

[philosofool]

An update and follow up question...


With that said, quick question... I mentioned previously that I decanted the wort that turned out to be unfermented, still sitting at 1.040 pts. Well even though I poured it into an unsanitzed glass and even dunked my beard into it (when I discovered it was still sweet), I went ahead and kept it without dumping it---put on a lid and stuck it in the fridge. This was about 4-5 days ago. So my question is, can I not just boil this a bit (maybe add some water to account for boil off) and use it for another yeast starter in the next couple of days? I can't see why not!

Anywho, thanks again to everyone who contributed info on this subject--your support and and advice is always much appreciated!

Boil it, freeze it and it will keep almost indefinitely. Re-boil when you actually make the starter just to be safe.