Can you pitch too much yeast?

[Cloud Surfer]

One of my first beers was a Rochefort 10 clone, which was also the first time I made a yeast starter. I’m sure I underpitched it and the fermentation got stuck way above FG. I did end up making another starter and got it going again.

So I’ve just started on another Rochefort 10 clone. I make nice starters now I know what I’m doing, however I decided to double step it this time for a bit of insurance. Required pitch rate was around 350 billion, though I ended up with over 600 billion in the starter.

Now I’m less than 48 hours since pitching, and it’s gone from 1.090 to 1.040. So it’s flying through fermentation at more than 1 point an hour. I’m wondering now if there is some side effect of such a fast fermentation. I’ve not heard about off flavours from pitching too much yeast, as the normal problem is pitching too little yeast.

 

[McMullan]

Well done, I say. Sounds like a spot-on fermentation. The probability of a home brewer over pitching is very remote. Aim to 'over' pitch. At the very least avoid any risk of under pitching, which is a much bigger risk for home brewers. Professional brewers are more likely pitching at much higher rates than home brewers. For many, yeast is a free byproduct. Don't worry about what appears to be a rapid fermentation. Yours sounds great. It'll probably slow down a tad before long due to the ethanol level, but if it carries on as it is, well bloody done! I find commercial beers fairly consistently 'cleaner' in terms of their yeast/ester profiles compared with a lot of home brew ales I've tried and made very well by others. But I think there's a culture of under pitching among home brewers that's been mainly influenced by commercial yeast suppliers servicing the home brew market. 'Just enough' translates into a viable business. Just a fact of business. Unfortunately, too, 'just enough' doesn't stay that way for long. It's not surprising that home brewers who harvest and repitch observe better fermentation performance in subsequent repitchings - more healthy yeast cells. Some people prefer amplified ester profiles and purposely pitch on the low side and accept relatively slow fermentations. Personally, the sooner ethanol is formed the better, as it selects against unwanted bugs and you can refill the FV sooner.

Edit: I am assuming you are managing temperature here. And just to be clear, I don’t think home brewers can over pitch healthy yeast. Pitching unhealthy yeast is another matter.

 

[hotbeer]

Depends on the beer style you are going for and whether you yourself like those tastes that may or may not be there.

Google on autolysis and beer making and you'll find some more info on it.

As for your particular brew, I don't know if that would even be way to much to be concerned about.

 

[Cloud Surfer]

Well done, I say. Sounds like a spot-on fermentation. The probability of a home brewer over pitching is very remote. Aim to 'over' pitch. At the very least avoid any risk of under pitching, which is a much bigger risk for home brewers. Professional brewers are more likely pitching at much higher rates than home brewers. For many, yeast is a free byproduct. Don't worry about what appears to be a rapid fermentation. Yours sounds great. It'll probably slow down a tad before long due to the ethanol level, but if it carries on as it is, well bloody done! I find commercial beers fairly consistently 'cleaner' in terms of their yeast/ester profiles compared with a lot of home brew ales I've tried and made very well by others. But I think there's a culture of under pitching among home brewers that's been mainly influenced by commercial yeast suppliers servicing the home brew market. 'Just enough' translates into a viable business. Just a fact of business. Unfortunately, too, 'just enough' doesn't stay that way for long. It's not surprising that home brewers who harvest and repitch observe better fermentation performance in subsequent repitchings - more healthy yeast cells. Some people prefer amplified ester profiles and purposely pitch on the low side and accept relatively slow fermentations. Personally, the sooner ethanol is formed the better, as it selects against unwanted bugs and you can refill the FV sooner.

Sweet, thanks. I agree the biggest problem among new brewers, for which I still include myself, is not pitching nearly enough yeast, and that’s the common theme we read about in the forums. But I’ve never read anything about a fermentation that ran too fast. So I was just curious.

 

[Cloud Surfer]

Depends on the beer style you are going for and whether you yourself like those tastes that may or may not be there.

Google on autolysis and beer making and you'll find some more info on it.

As for your particular brew, I don't know if that would even be way to much to be concerned about.

I wasn’t worried about autolysis. I have good fermentation control in my conical, and can dump out the bottom if needed. The longest I leave my ales in primary is 4 weeks for the big ones. This one will probably see 3 weeks until shifting off yeast for conditioning.