Yeast over pitch

[Sergiy]

Hi, i have added one package of Fermentis Safale US-05 to a 5 litres of wort with 1.060 gravity. As i found out later from different calculators, that i have to use 1/3 of a package. Did i over pitched, and how i may affect the result?

 

[bernardsmith]

Hi Sergiy - and welcome.
Can home brewers really "over-pitch"? What is the downside to adding a few billion more cells to the gallon of wort other than a more active fermentation? If there is enough O2 at the pitch and enough nutrients for the yeast what exactly might be the downside? The upside, of course, is that any next brew you make will be made with a sterile packaged yeast and not one exposed to moisture and bacteria that comes from an opened pack returned to the fridge...

 

[lablover]

You'll be fine. I've made great beers racking fresh wort onto an entire yeast cake. That's way overpitching according to calculations.

 

[Calder]

Yes you over-pitched. Result is yeast will not reproduce as much as it would have if you had pitched the right amount, so the beer will be made with 'old' yeast rather than new yeast.

What is going to happen .... probably nothing that you will be able to detect. Fermentation may end up a point higher than it otherwise would have, but you will never know. The yeast may not create all the esters that it would have done normally, but it is SO-5, a clean yeast, so that doesn't matter. There may be other issues with over-pitching, but I've not heard of any real issues being reported, and many people have pitched on whole cakes with no issues.

 

[Jwood]

You will be fine, especially if you didnt rehydrate the yeast, which knocks off quite a bit of viability. Even if you did rehydrate you have to overpitch by quite a significant amount to notice ill effecfs. Proper pitch/fermentation temperature and sanitation will be much more important for you.