pitching rates question

[MHBT]

how much over the pitching rate of a particular beer will have a negative affect on your beer? For example say you are brewing a lager and the recommended pitching rate is 1.5m cells/ml/*p and you pitch 3m cells/ml/*p is that enough to affect the beer in a negative way? In other words when is it truly too much yeast,how much can you go past recommend pitching rates? when ever i make starters there is alot of faith put into yeast calculator cause i do not own a microscope so for all i know i can be under or over pitching my beers without even knowing

 

[Big Monk]

For example say you are brewing a lager and the recommended pitching rate is 1.5m cells/ml/*p and you pitch 3m cells/ml/*p is that enough to affect the beer in a negative way?

Say you are using cold fermentation techniques for a lager and holding the entire fermentation between 45-48 F the entire duration. 3 M/ml/P wouldn't be that much of an over pitch, to be honest. As a general rule, we are recommending people use 2.5 M/ml/P when fermenting cold. So the answer to your question may be temperature dependent as well. If you use an accelerated lager fermentation schedule, you may want to be in a lower range, i.e. the oft quoted 1.5 M/ml/P.

In other words when is it truly too much yeast, how much can you go past recommend pitching rates?

I'd say over/underpitching yeast would be more of "concern" with more ester driven styles. Trappist yeast, etc. where fermentation byproducts are a part of the finished flavor profile and also can be manipulated by combinations of fermentation parameters like temperature, pitch rate, etc.

Whenever I make starters there is a lot of faith put into yeast calculators because I do not own a microscope, so for all I know I can be under or overpitching my beers without even knowing.

Very true. There is no real way of knowing exactly what you are pitching unless you count the cells. This is fortunately not all that hard and the equipment isn't terribly expensive. You could probably set up a small counting "lab" for under $100. This may actually be worth doing if you repitch slurry with any regularity, but also helpful for knowing viability of newly purchased yeast as well.

 

[MHBT]

Say you are using cold fermentation techniques for a lager and holding the entire fermentation between 45-48 F the entire duration. 3 M/ml/P wouldn't be that much of an over pitch, to be honest. As a general rule, we are recommending people use 2.5 M/ml/P when fermenting cold. So the answer to your question may be temperature dependent as well. If you use an accelerated lager fermentation schedule, you may want to be in a lower range, i.e. the oft quoted 1.5 M/ml/P.



I'd say over/underpitching yeast would be more of "concern" with more ester driven styles. Trappist yeast, etc. where fermentation byproducts are a part of the finished flavor profile and also can be manipulated by combinations of fermentation parameters like temperature, pitch rate, etc.



Very true. There is no real way of knowing exactly what you are pitching unless you count the cells. This is fortunately not all that hard and the equipment isn't terribly expensive. You could probably set up a small counting "lab" for under $100. This may actually be worth doing if you repitch slurry with any regularity, but also helpful for knowing viability of newly purchased yeast as well.

Right on thanks for the info, my next batch is a lager(OG 1050) i plan on fermenting at around 49-50F, my first starter step is 1.5 liters and i am going to decant and add 3 liters of fresh wort, according to the yeast calculator should give me a pitch rate of 2.5 m/ml/p, so without knowing exactly my pitching rate and cell count that should get the job done right?

 

[Big Monk]

Right on thanks for the info, my next batch is a lager(OG 1050) i plan on fermenting at around 49-50F, my first starter step is 1.5 liters and i am going to decant and add 3 liters of fresh wort, according to the yeast calculator should give me a pitch rate of 2.5 m/ml/p, so without knowing exactly my pitching rate and cell count that should get the job done right?

I'd say so. As far as estimation goes that should be in the ballpark. Are you planning on holding 49 F the whole time?

 

[MHBT]

I'd say so. As far as estimation goes that should be in the ballpark. Are you planning on holding 49 F the whole time?

probably more leaning towards 50F for primary then around 60 for a D rest. Would it be wise to up my pitching rate to 3m/ml/p?

 

[Big Monk]

probably more leaning towards 50F for primary then around 60 for a D rest. Would it be wise to up my pitching rate to 3m/ml/p?

I was just going to say that cold fermented lagers typically don't require a diacetyl rest. So if you pitch enough healthy yeast, get sufficient nutrients from wort production (or added prior to fermentation), and hold about 48 F the whole time, you shouldn't need to raise the temperature at all. Just keep it at primary fermentation temperature the whole time.

Healthy yeast and cold temperatures work in conjunction to limit the production of the diacetyl precursor. If it isn't there, you don't have to get rid of it.

Just a suggestion though. Do what works for you.

 

[MHBT]

I was just going to say that cold fermented lagers typically don't require a diacetyl rest. So if you pitch enough healthy yeast and hold about 48 F the whole time, you shouldn't need to raise the temperature at all. Just keep it at primary fermentation temperature the whole time.

Just a suggestion though. Do what works for you.

Yes i have known that a D rest is not always needed as long as pitching rates/yeast health is good but i take it out for a D rest just to free up the fermentation chamber, well thanks for all the info, i think im gonna stick with 2.5m/ml/p pitch rate and hope for the best.cheers