effects of overpitching?

Going to transfer 5 gallons of 1.070 wort onto a US05 yeast cake from a 1.047 blonde. I have done this many times with beers of similar gravities without any ill effects. I did not realize until recently that I was overpitching significantly. I suppose I could only use a portion of the yeast cake but I don’t really want to worry about it.

What are the negative effects of overpitching?

The main worry is the beer would be “too clean.”

I am okay with that considering I am using US05

Some effects of overpitching can be- low or unexpected esters, yeast autolysis flavors, poor head retention and lower attenuation. Generally the effects are more apparent on future generations.

Yes on the under attenuation. The theory I have heard is that the older generation of yeast poops out and not enough youngins were made to finish it off. I think autolysis is minimal risk. Never heard of the head retention issue. Wonder what would be behind that.

Overpitching a healthy culture is more likely to result in overattenuation than underattenuation.  The place where overpitching hurts is in future generations. Overpitching as a practice causes the average age of the cells in the culture to rise over time, resulting in declining performance.

If you decide to crop from this batch, crop between 100 and 150 milliliters of thick slurry.  A thick slurry that contains 40% yeast has around 1.2 billion cells per milliliter.  Contrary to what the yeast calculators tell you, 120 billion viable cells will attenuate a 5-gallon batch of well-aerated wort up to 1.060s without breaking a sweat.  In fact, if one’s sanitation practices are solid, 60 billion viable cells will do the job.

bringing this back to life as I’m just getting into drinking an altbier that I pitched ale yeast in the quantity that would have been required for a lager yeast.  i hit my FG on the head.  the brew tastes to me kind of like it was scrubbed clean.  i pick up a seltzer water type taste.  can anyone concur with these observations or tell me that i’m making it all up?

it might be one of those things… tastes awesome until you realize you made a mistake, then it never tastes the same again  :o

Ha!  I have experienced that one before.  Is it properly carbed up and are you allowing it to warm up a bit before sampling?

Carbed up by putting it at 25 psi for a few days, then backed off to 10ish.  maybe that accelerated method has an impact and i would have been better off skipping the few days at a higher pressure.

warmed a bit as i contemplated my sanity and brewing methods.  can’t wait to try it again tonight… is it 5 o’clock yet?