Can u step up a starter and equal 2 smack packs?

[rdbrett]

Rookie here. Have 2L starter. Can I step it up and equal the cell count of two packs? Is that possible with a 2L flask?

 

[aeviaanah]

Yes try yeastcalc.com. Mess with the numbers both in the first and second step as yeast growth is not linear. Take care!

 

[rdbrett]

So the first step is my original starter? According to this if I step it up I will have more than I need. Hmmm. How close is close enough?

 

[WoodlandBrew]

The actual cell count can be pretty far off from the calculators, but the closer you get the numbers the better. 50% difference from calculated to actual is not uncommon.

1 smack pack with 100g of DME in 1 liter of water will yield about 2 packs worth in one to two days.

 

[rdbrett]

On those calculator sites, it has me making a 2L starter. Would I make both it and the step up 2L?
I do have a stir plate.

 

[WoodlandBrew]

If you are using a stir plate the best cell count estimator I know of is Kai's on Brewers Friend. It's the only one I know of that has real measurements backing the cell count estimations.

 

[rdbrett]

When you step it up, is there enough yeast nutrient in a Wyeast smack pack? Or do you add some nutrient? I have some. But not sure if necessary.

 

[WoodlandBrew]

DME has just about everything yeast needs. If you are using tap water then it will have the calcium as well. No need for yeast nutrients.