Friend goofed up yeast pitch--options?

[mongoose33]

I have a process where I don't do a double-starter for a lager. I'll do a 1-liter starter (with oxygen and yeast nutrient), then pitch the entire thing at about 14 hours into the fermenter at about 68 degrees. I'll let it sit at that temp for about 5 hours, then drop it down to 50 degrees to continue fermentation.

Essentially, I'm giving that starter time to increase at room temp before it drops to 50. Typically I'll have signs of fermentation (bubbling and krausen formation) as soon as 5 hours after pitch. It works, works well, and I like it.

HOWEVER. A friend of mine helped with brew day yesterday and he brewed my Darth Lager. He was going to follow my recipe and process--except at the end, he didn't.

We finished the brew day at 5:30pm. At that point, we oxygenated the wort, and he took his fermenter home to ferment in his own ferm chamber. I instructed him to pitch the yeast immediately on getting home, so that it would be at about the same temp as the wort.

Well, it didn't happen that way. He pitched about 6pm, which was at that point about 19 hours after he began his starter. The wort was probably about 64 degrees (he's not sure, but that seems reasonable), the starter probably 70 or thereabouts. He didn't wait the 5 hours before dropping to 50 degrees, he set it at 9:30 to start dropping. (He'd been up since 4:00am and needed to crash).

This morning, no sign of anything. No bubbling, no krausen forming. With this method of doing a starter and pitching it warm and waiting a bit, I always get action within 8 hours. In fact, I did an Amber yesterday, same deal with a starter, and had action within 6 hours.

So--I must admit I have no idea what to advise him. It was his first starter, but he had a decent krausen on it. He said he followed my process of oxygenating and adding a bit of yeast nutrient to the starter wort.

I know the acronym (RDWHAHB) and while he'll likely get beer out of this, it seems to me to clearly be an underpitch. What do we do? Just wait it out? BTW, the yeast is WL940, Mexican Lager Yeast.

Thanks for any ideas.

 

[MapleGroveAleworks]

You severely underpitched and got it down to lager temp fairly quickly. It'll ferment, it's just going to take longer. You'll see fermentation signs within the next 24-48 hours.

The yeast were entered into an environment where they will be slightly stressed due to the fact that they're beginning fermentation with only about 33% of the required yeast cells at that temperature. There may be off flavors due to stress, but probably not. It's more that you'll see a longer lag time before it begins.

 

[mongoose33]

You severely underpitched and got it down to lager temp fairly quickly. It'll ferment, it's just going to take longer. You'll see fermentation signs within the next 24-48 hours.

The yeast were entered into an environment where they will be slightly stressed due to the fact that they're beginning fermentation with only about 33% of the required yeast cells at that temperature. There may be off flavors due to stress, but probably not. It's more that you'll see a longer lag time before it begins.

We did see that, and I knew that would happen.

At this point--today, which is 2 1/2 days after pitch--do you think it would be valuable to just add another pack of liquid yeast to the fermenter to at least get the cells closer to what they need to be?

 

[jlinz]

We did see that, and I knew that would happen.

At this point--today, which is 2 1/2 days after pitch--do you think it would be valuable to just add another pack of liquid yeast to the fermenter to at least get the cells closer to what they need to be?

Yes. My fear would be with the chance of infection. Good to let the yeast get the upper hand as soon as possible.

 

[MapleGroveAleworks]

We did see that, and I knew that would happen.

At this point--today, which is 2 1/2 days after pitch--do you think it would be valuable to just add another pack of liquid yeast to the fermenter to at least get the cells closer to what they need to be?

It can't hurt. Maybe a dry rehydrated lager yeast pack since that's much higher in cell count than a liquid pack/vial?

And yep what @jlinz said is correct. The longer the yeast take to take hold of the fermentation, the higher the risk of infection. But honestly I think you'll be just fine, just pitch some more yeast.

 

[chris000]

Maybe a dry rehydrated lager yeast pack since that's much higher in cell count than a liquid pack/vial?

And yep what @jlinz said is correct. The longer the yeast take to take hold of the fermentation, the higher the risk of infection. But honestly I think you'll be just fine, just pitch some more yeast.

X2
I always have one ale and one lager strain of dry yeast in my fridge - just in case I get spooked in the middle of the night LOL.
Might be a little bit too late by now.
Regarding off-flavours, pitching warm the entire starter medium, starting fermentation for a bit and then cooling is a fast/cheap method, but not necessarily the safest IMHO. Cannot say I never did it, but cold starts with high cell counts (2+ generations of starter) have never failed me.
What would be really interesting is if you have split the batch with your friend and are able to compare your standard method to what he did.

 

[mongoose33]

I bought another pack of liquid yeast today and my friend added it. I think it'll turn out ok. He had a krausen forming after 24 hours, and he's got a fairly good one now.

I typically use an accelerated fermentation schedule w/ these lagers, but with this one, I think we'll just let it play out at 50 degrees, then do a diacetyl rest at the end.