[Richard]

FWIW, I've reached the conclusion that pitching active yeast makes much more difference than cell count does. For that reason,  I say make a starter.

True!  But making sure that I don't over-pitch is why I use the calculator.  I have always heard that slightly under-pitching is better than over-pitching and I always have really good results with that method.

I thought it was really hard, impossible, for homebrewers to over pitch?

Here is how to overpitch: Take a fresh package of an ale yeast with 150 - 200 billion cells and make a 2 liter starter with it (a 1 liter starter would be too small for that number of cells).  Pitch that whole 2 liter starter into 5 gallons of wort of OG 1.035. You would have something like 5 times the number of yeast cells you need. I think that would count as an overpitch.

Maybe. Keith recently posted info indicating that a large amount of yeast into a small amount of wort doesn’t result in significant cell growth.

Exactly. There is no need for any more cells, so no growth. Many of the flavor compounds are generated during the growth phase, so they will be lacking.

[denny]

FWIW, I've reached the conclusion that pitching active yeast makes much more difference than cell count does. For that reason,  I say make a starter.

True!  But making sure that I don't over-pitch is why I use the calculator.  I have always heard that slightly under-pitching is better than over-pitching and I always have really good results with that method.

I thought it was really hard, impossible, for homebrewers to over pitch?

Here is how to overpitch: Take a fresh package of an ale yeast with 150 - 200 billion cells and make a 2 liter starter with it (a 1 liter starter would be too small for that number of cells).  Pitch that whole 2 liter starter into 5 gallons of wort of OG 1.035. You would have something like 5 times the number of yeast cells you need. I think that would count as an overpitch.

Maybe. Keith recently posted info indicating that a large amount of yeast into a small amount of wort doesn’t result in significant cell growth.

Exactly. There is no need for any more cells, so no growth. Many of the flavor compounds are generated during the growth phase, so they will be lacking.

That's the theory and it's what I found in practice.

[brewthru]

"Here is how to overpitch: Take a fresh package of an ale yeast with 150 - 200 billion cells and make a 2 liter starter with it (a 1 liter starter would be too small for that number of cells).  Pitch that whole 2 liter starter into 5 gallons of wort of OG 1.035. You would have something like 5 times the number of yeast cells you need. I think that would count as an overpitch."

This is theoretical. Correct? Similar to "If we stop our car by crashing into a wall this is not good for the car or us."

My question, as homebrewers, whom does such a HUGE step up?

[denny]

"Here is how to overpitch: Take a fresh package of an ale yeast with 150 - 200 billion cells and make a 2 liter starter with it (a 1 liter starter would be too small for that number of cells).  Pitch that whole 2 liter starter into 5 gallons of wort of OG 1.035. You would have something like 5 times the number of yeast cells you need. I think that would count as an overpitch."

This is theoretical. Correct? Similar to "If we stop our car by crashing into a wall this is not good for the car or us."

My question, as homebrewers, whom does such a HUGE step up?

Lots of people do.

[brewthru]

"Lots of people do."

How is this known?

[denny]

"Lots of people do."

How is this known?

From talking to MANY homebrewers. From answering questions from people on many different platforms. Remember, my "job" is to interact with homebrewers. I spend hours a day doing that.