Under Pitched

[Max2660]

Hi guys,

I brewed a Black IPA last night (Extract kit with special grains) and I chose WLP001 yeast with the kit.

I'm a beginner so i made a little error and didnt gauge the water properly with the foam and all so i'm at 17L instead of 20L and 1.063 OG instead of 1.059.

Didnt make a starter because of my lack of knowledge and equipment.. So i'm pretty sure i underpitched. And 24 hours later still no activity.

Do i add some dry coopers yeast i have on hand now, order some more WLP001 this week or let it be?

And do i add water to bring down my OG to the expected 1.059??

Thanks!

 

[Malticulous]

If anything I'd add another WLP001. It probably will be fine. It will just take longer.

 

[Redhook]

I'd add two or three more vials to ensure a healthy fermentation. And your probably going to need a blow off tube. You need to add the yeast today so get it from a local home brew shop. You can also just add a packet of US-05 since it is the same yeast as WLP001.

 

[WoodlandBrew]

Next time you might want to consider pitching more yeast, but for this batch I would let it go. After two days given your gravity and starting cell count you are probably at about 2 trillion cells. Adding a couple hundred billion isn't going to make much of a difference at this point.

For our Cell Density Meter Kickstarter I'm going to talk about this more, and also have an interview with a biologist to explain it further, but it's really just the first several hours where pitch rate makes a difference. In a nut shell it has to do with the yeast changing the wort to suit their needs and also the yeast changing themselves to suit the wort.

Fermentation Model

 

[Malticulous]

Wyeast's calculator shows pitching one pack into five gallons only producing about 650 billion cells. I agree to just let it go as is though.

I consider a healthy cake to be 800 billion cells. That's how I figure my re-pitch rates anyway. If this was pitched with a pack a of US-05, two vials or a two liter starter (~9-10 million/ml) 800 billion is about what it would have produced. The lag phase would have been much shorter--but I'd bet it's bubbling away by now.

 

[Max2660]

Thanks guys,

I added half a pack of US-05 last night, still no bubbles.

I'll be patient and let the yeast do it's thing and see what happens!

 

[Max2660]

Turns out my lid does not make a perfect seal (First time using this fermenting bucket) so it was breathing by the lid instead of the airlock.

I taped all around the lid and the airlock is bubbling nicely now!

I will see the results in 6 weeks !

 

[WoodlandBrew]

Wyeast's calculator shows pitching one pack into five gallons only producing about 650 billion cells.

Did you adjust for the gravity of the wort? Each gram of extract produces 1 billion cells. This follows the balling observation as well as my research.

 

[Malticulous]

If 5° plato could some how triple yeast growth I'm pretty sure I would have noticed the different size of the cakes. I've never calculated extract in grams.

After two days given your gravity and starting cell count you are probably at about 2 trillion cells.