Pretty sure I under pitched...

[IndyBlueprints]

Made a 13-ish gallon batch of IPA.
OG was 1.073.
I made a 2 liter starter from a can of Imperial Barbarian yeast.
Let it sit in fridge for 24 hours to drop out.
Poured off about 2/3 of liquid, and split remaining between 3 fermenters of 4-ish gallons each.
Wort was about 73F when pitched.
Now at day four, each batch is at about 1.025, and all airlock action has died.

I know 4 days isn't much, but Imperial Barbarian is a fast-acting yeast. I'll give it a couple more days and check it again, but if it's stuck because of under pitching, what can I do?

 

[MapleGroveAleworks]

Airlock activity isn't indicative of fermentation happening. My bet is you check in a couple days and it has dropped more. You definitely underpitched though. What temp did it ferment at? Hopefully lower than the 73 you mentioned?

 

[parrothead64]

If you need to add more yeast, make another starter and pitch it at high Krauson . If you pitch yeast that is not currently active, there is not enough sugar and too much alcohol for them to get going. Active yeast will finish the job. I agree that you should wait a bit and check gravity again before you do it.

 

[kh54s10]

You might not have underpitched. Their website says the cans contain 200 billion cells where as Wyeast and White Labs contain closer to 100 billion.

Even with an underpitch the yeast should multiply sufficiently to ferment the beer. It is off flavors during the growth phase that you try to avoid by making a starter.

I agree that your beer is most likely still fermenting and if you give it another week and a half you should be good. Airlock activity often stops before final gravity is reached. Sometimes by a week or so.

 

[IndyBlueprints]

Airlock activity isn't indicative of fermentation happening. My bet is you check in a couple days and it has dropped more. You definitely underpitched though. What temp did it ferment at? Hopefully lower than the 73 you mentioned?

Fermentation area ambient temperature is about 67ºF.

I'll give it a few days.

 

[MapleGroveAleworks]

Fermentation area ambient temperature is about 67ºF.

I'll give it a few days.

I bet you're good but check in a few days and if it's truly stalled, yeah add a new starter at high krausen and it'll finish up.

 

[radwizard]

If you have a fresh can of imperial and made a 2 L starter, you have about 400 billion cells. Your batch required around 650 to 700. I would consider pitching more yeast.

 

[IndyBlueprints]

Well, it’s 11 days in, and all 3 fermenters stalled at 1.020. I dry hopped each with different hops.
The first with 2ounces of experimental 07276 @ 16.6% AA.
The 2nd with 2 ounces of Lemondrop @ 5.2% AA.
The 3rd with 1/2 ounce of Mosaic Cryo pellets @ 24.1% AA.

The hoppiest one is the one with the exp 07276. I think it’s bitter enough to counteract the sweetness. The other two are just too sweet. So, my plan is to make another 2liter starter with a can of Imperial Barbarian.

At what point should I add the starter to the beers? I’ve heard at “high krausen”, but when is that? I always use a stir plate for continuous aerating.

 

[hottpeper13]

If you plan on decanting your yeast ,you need to give it enough time to drop CLEAR!! You want to be able to read through the beer before decanting. The reason is that the yeast cells still in suspension are the ones that finish up the ferment. The Conan type is non flocculant and I pitch the whole thing with great success. My process now is to make a small 1L starter 24hrs on stir plate then save ~300ml for the next one. The next day is brew day and after the wort has boiled 10 min I take a liter out and chill it , then pitch into starter. I will then pitch the whole thing within 24 hrs (most ofthe yeast is ready in 12) at high krausen or just after. i haven't had a ferment stall since I stopped decanting my starters. Until then I would make a starter of TYB Belgian Dry and pitch it at high krausen. Most of thime doing that doesn't work and your stuck with it.

 

[IPAfreek]

I am actually having the same issue right now. Brewed a smoked porter and used wyeast 1056 American ale. Made a 2L starter and pitched at 69 then brought it down to 67. OG was 1.062 and has stalled for the last 4 days at 1.022. Need to get this sucker down to 1.012 ish. Even tried upping the temp to 71 and it didn’t even budge!

 

[Northern_Brewer]

At what point should I add the starter to the beers? I’ve heard at “high krausen”, but when is that? I always use a stir plate for continuous aerating.

Krausen is the "head" that develops on top of a fermenting beer, and high krausen is the point at which there's most foam, and notionally the point at which the yeast are most active. Typically it's 2-3 days after pitching in a FV but the timing varies a lot depending on the yeast strain and environmental conditions. Obviously with a stirplate you may not see much krausen and you have to go by experience, things tend to happen rather quicker when stirred. Having said that, depending on the nature of your starter, there's a good argument for letting the yeast go past the stage of most activity and letting them build up food reserves before pitching, John Palmer talks about it here.

 

[IndyBlueprints]

I gave it a full two weeks and it didn’t drop below 1.020. So I added a rehydrated dry pack of US005. After 5 more days, it’s remained at 1.020. So, I’m pretty sure all the fermentable sugars have been eaten up.

Looks like I’m just going with a slightly sweeter IPA, and mash at a lower temp next time.