Yeast Starter Sizing for Smaller Batches

[hafmpty]

I make 2.5gal batches with ≈3gal going into the fermenter. I have heard Jamil Zanisheff via Brew Strong say that you don't want to make a starter smaller than 1 liter. If he gave a reason, I can't remember why.

However, on most of the beers I make, even a 1 liter starter would have me pitching at a rate of 2+ billion cells per mL per degree plato vs. the standard 750 million cells per mL that is often recommended.

I'm brewing on Monday (5/16) and the yeast calculators are telling me that with the yeast I have I need to make a 500mL starter for one batch and a 350mL starter for the other to get me in the right pitching range.

I've thought about making a 1L starter and then only pitching a certain percentage of that. The trouble is my fermenter headspace is limited and I don't want to pitch starter wort into my small batches as it has the potential to affect flavor.

What do you all think about making smaller starters?

 

[WrQth]

Over-pitching a little won't hurt so I would make a 1 liter starter, decanting most of the liquid after cold crashing it, rouse the yeast back into suspension then pitch half of the volume of starter.

 

[m00ps]

build up your starter a few days before hand, let it settle overnight, then you can decant 90% of the starter wort before pitching. I try to minimize the amount of oxidized 1.040 starter wort that goes into my final beer

1L worth of yeast seems fine for a 3gal batch. I wouldnt worry too much on it. It is very hard to overpitch to the point fo causing issues at a homebrew level

 

[hafmpty]

I guess I'm mostly wondering if smaller starters are OK to make. Is there a risk that it will produce sub-standard yeast or if it will be unhealthy or anything like that?

 

[WrQth]

It's ok to make a small starter you just won't get as good of a growth rate as with a 1 liter started hence when people say make at least a 1 liter starter. If you get the number of cells you need for your batch from a small starter those yeast are just as viable as from a larger starter.

 

[TheHopfather]

I typically brew the same sized batches as you (takes me too long to drink 19L and I enjoy variety). When I'm making starters I go with a 1L. What I'll do is boil a small mason jar, typically 200mL, to sanitize it and then I'll fill it with starter before I cold crash the starter.

This way I end up with some clean, saved yeast in my fridge and 800mL of starter for my beer. I also cold crash and decant the starter to limit volume going into the carboy. Works for me!

 

[hafmpty]

It's ok to make a small starter you just won't get as good of a growth rate as with a 1 liter started hence when people say make at least a 1 liter starter. If you get the number of cells you need for your batch from a small starter those yeast are just as viable as from a larger starter.

That's what I assumed. I did a bit more research too and found this in the Yeast book by White & Zainisheff.

"A high concentration of yeast in a small amount of wort results in very little growth. The 500-milliliter starter barely grew*, only a fraction of a doubling. The fundamental fact is that yeast cannot grow unless they have enough sugar and nutrients for each cell to divide. While the cells do not multiply much when the inoculation rate is this high, it can still benefit the existing cells. The takeup of sugar, nutrients, oxygen, and the production of compounds such as sterols, improve cell health. Starters rarely have a negative side; even if there is little yeast growth, a starter helps to revive yeast for fermentation by activating metabolism, and therefore fermentation starts faster."

* This is in reference to an experiment they conducted w/ 100 billion cells in various sizes of starters & the resulting cell growth. The 100 billion cells in 500mL of starter wort only saw an increase of 12 billion cells. This was a non-oxygenated, non-stir plated, starter.

I also found this in the March/April 2007 issue of Zymurgy where Jamil has a Q&A section on yeast starters.

"[Neva] Parker [White Labs VP of Operations] says putting a fresh vial of yeast into 500 milliliters of wort and letting such a small starter go to completion can actually leave the yeast less ready to ferment a batch of beer. The yeast do not rebuild their reserves and have very little increase in cell mass. The minimum starter size for significant yeast growth from a vial or pack of yeast is 1 liter. One vial or pack into 1 liter results in approximately a 50-percent increase in cell mass. Some brewers make a small starter volume (500 ml or less) with the sole intent of “waking” the yeast. When making small starters, it is best to pitch the entire volume at the height of activity."

It seems that the theme here is that pitching a large dose of yeast into a small volume of wort isn't good for the yeast IF you let them ferment out completely. And if you do put them into a smaller volume of wort, know going into it that you won't get a lot of reproduction.

A solution I've been looking into is the "vitality" starter that the buys at Brulosophy.com have mentioned. This is essentially what the Q&A says is the "waking up" kind of starter.

I typically brew the same sized batches as you (takes me too long to drink 19L and I enjoy variety). When I'm making starters I go with a 1L. What I'll do is boil a small mason jar, typically 200mL, to sanitize it and then I'll fill it with starter before I cold crash the starter.

This way I end up with some clean, saved yeast in my fridge and 800mL of starter for my beer. I also cold crash and decant the starter to limit volume going into the carboy. Works for me!

That's a great idea. I brew 2 batches a month on the same day so there's about 1 month in between brew days. I'll look into this technique as it would definitely save me a bit of money and could help with adjusting my pitch rate as well. Thanks!