How much yeast do you REALLY need?

[downzero]

I have never had a beer fail to ferment or have a stuck fermentation. I generally use dry yeast but my NEIPA I just made with liquid yeast and no starter (1.066) was done after 3-4 days. I fail to see the point of all this concern over pitch rates. I've had similar luck with repitched yeast.....what I get out of the fermentation is beer every time. I am thinking about making some starters in the near future just to see if the beer tastes any different, but I'm really having a hard time figuring out why. And as for commercial breweries pitching the equivalent of 3 vials, in that case, we're all massively underpitching and the calculators are all too modest. My yeast sure don't seem stressed, though.

 

[CascadesBrewer]

Interesting thread and interesting to see the wide advice and practices from experienced brewers. I do feel like yeast health and management are things that you need to play with and adopt a process that works for you.
My overall thoughts on yeast and fermentation is that:

1. It is one of the most important aspects of making great beer.
2. There are a dozen factors that impact this (pitch rate, yeast health, ferm temp, aeration, etc.)
3. If you do a few of them well, you can get by with lesser practices on the others.

For many years my general practice was to make a small starter (~24 oz, 600 ml) with a new pack (Wyeast/White Labs). I made the starter the evening before and pitched the entire active starter. I don't have a stir plate. I am coming back to the realization that this simple process might be my preferred method, even if the cell count growth is minimal.

I often do 2.5 gal batches and direct pitch a new pack. This is a good way for me to try out new yeasts and build up yeast for future batches.

These days I harvest yeast from my fermenter. I have had very good results direct pitching the slurry from either a 16 oz or 8 oz jar into a 5 gal batch. I like the idea of not messing with making a starter. I am still trying to figure out how much the age of the yeast impacts this.

I am starting to cycle back to making a starter with my harvested yeast by mixing up 24 oz of starter, and pitching the slurry from an 8 oz jar of yeast and then direct pitching the active starter into my batch. I am finding that I get faster starts and more vigorous fermentations. Even if the beer is not better, it is done a day or two earlier. It is always reassuring to see some signs of fermentation before going to bed on brew day. I did this for a 5 gal batch of a 1.118 Imperial Stout and I had excellent fermentation and attenuation (seems to taste okay...aging on oak cube now).

 

[Hoppy2bmerry]

@odie Perhaps, but just because you can, doesn’t mean you should ... off flavors. The variables with liquid... how was it handled before you got it? Was the correct temp held steady? Is it past its prime? A starter fixes that or won’t, but at least you know if you are pitching viable yeast.

 

[bleme]

at least you know if you are pitching viable yeast.

This is probably the most easily justified answer for me. I pitched dead yeast once. It sucked. I haven't bought liquid yeast since then, because I hate the bother of starters...

 

[mattdee1]

My overall thoughts on yeast and fermentation is that:

1. It is one of the most important aspects of making great beer.
2. There are a dozen factors that impact this (pitch rate, yeast health, ferm temp, aeration, etc.)
3. If you do a few of them well, you can get by with lesser practices on the others.

^^ this is a balanced take; I like it.

 

[Nanuk-O-Dah-Nort]

Technically you need "1"

and under optimum conditions, in one day, you'll have over 1Trillion

So...

But to make a specific taste/product, there are optimum amounts.

but it would seem other amounts work fine also.

 

[CascadesBrewer]

Technically you need "1" and under optimum conditions, in one day, you'll have over 1Trillion

So I am pretty sure that this idea is just false. I am not sure if 1 cell could grow to a trillion in one day but "optimum conditions" involve continuous stirring and aeration. That is good for yeast growth but makes terrible beer. In a standard wort there is just not enough oxygen and nutrients to support the number of generations of growth needed to get close to 1 trillion from 1. It would take 30 generations to get from 1 to around 1 billion, where pitching 2 billion cells only needs a few generations to get to 8 billion (which is a number I have read is what you end up with in a 5 gal batch with a decent pitch).

So maybe you don't need to pitch 2 billion (in a typical 5 gal 1.055 batch), maybe 1 billion works fine, maybe 500 million active yeast works well...but pitching 1 or 1,000,000 cells is bound to lead to issues.