Any danger in over-pitching?

Let's say I have a 2k ml flask and Mr. Malty tells me I only really need around 1260 ml for the batch I am about to brew. What if I make up 1.6 to 2k ml at 1.035 or so and pitched that? Any issues I should be concerned about?

Lack of esters, hot fusel alcohols, and bitter yeast bite are the most common complaints about over pitching. Doesn't happen every time, but why risk it?

And for that matter, why not make the recommended starter amount? Save money on DME, less liquid to deal with, etc

kanzimonson said:

And for that matter, why not make the recommended starter amount? Save money on DME, less liquid to deal with, etc

Click to expand...

It's that "more the merrier" thing...

I just hadn't read much on the ill-effects of over-pitching and thought i would ask. I have indeed used the suggested recipe (@ Mr. Malty), this was merely a hypothetical query.

Realistically, any amount of yeast from 1/3 of optimal to 3x optimal or so is unlikely to make any difference. People pitch right on a yeast cake from a prior fermentation (many times the optimum count) with little to no problems.

jldc said:

Realistically, any amount of yeast from 1/3 of optimal to 3x optimal or so is unlikely to make any difference. People pitch right on a yeast cake from a prior fermentation (many times the optimum count) with little to no problems.

Click to expand...

Little to no problems that they are able or willing to perceive, anyway. It is no coincidence that fermentation control is the one constant among successful competition brewers.

Consequences of overpitching include increased ester production and acetaldehyde production.

remilard said:

Consequences of overpitching include increased ester production

Click to expand...

You're gonna have to explain that one to me.

When overpitched, the temp inside can rise higher and faster than at normal pitching rates. The yeast can also be more stressed out (especially in the case of pitching directly on a cake from a previous batch) leading to an increase in ester production. With proper temp control some of this can be alleviated, but then you run the risk of decreased ester production leaving you with a flat tasting beer.

Yeast also tends to race through the sugars when overpitched, and when the sugars are gone, the yeast drops out and goes dormant on the bottom of the fermenter without cleaning up after themselves. This will result in very noticeable levels of acetaldehyde in the finished beer, and could also lead to sulfur compounds and diacetyl being present in detectable levels as well.