I (and some very generous volunteers from the NB forum) recently conducted an experiment to determine what, if any, impact under-pitching would have on a beer. The results more or less conform to the conventional wisdom - slower fermentation, increased off-flavors, etc. I know a lot of people, especially new brewers, question the need for starters, and I think the tasters’ results make a pretty persuasive case for using them.
That is fantastic. Thanks for the indepth analysis.
+1000
Thanks for the post. It humbly reminds us that it is the yeast that make the beer.
I used to think doing a yeast starter was overkill (Erlenmeyer flasks, stir plates, test tubes, etc.) and an unnecessary expense.
I thought, “What’s the difference if I pitch one cell or 100 Billion–it will eventually multiply and ferment the beer and finish the same?”
I was only half right–the FG finishes the same, but it doesn’t taste the same.
Use a starter to ensure you have enough healthy yeast to do the job right.
Now, I just need to get my fermentation fridge set up to ensure the yeast have optimal temperatures in which to do their work…
I experienced this first hand when I first started brewing many years ago. This is a testament to the fact.
Really nice work!
this will provide a valuable link for the nay sayers and/or beginners who question the need for a starter. Thanks!
I think I preferred the underpitched beer if I read the results correctly! :-[
Very nice… I tossed a link to it up on the Falcons website.
9/30 testers could correctly identify the underpitched sample.
I wonder if this is related to about 25% of the population being “Supertasters”?
http://en.wikipedia.org/wiki/Supertaster
It would be interesting to see if there was a correlation between their tasting/brewing experience level and correct identification.
Not in my case! 
From the article:
Based on the relative frequencies of some words, I think one can reasonably conclude that the under-pitched beer was perceived to be more bitter, more astringent, more solventy, less sweet, and – bizarrely – cleaner than the beer using the standard rate. Obviously, the increased perception of negative characteristics makes a persuasive case for the use of higher pitching rates.
Cleaner and more bitter were the 2 attributes I detected that made me prefer the underpitched beer. To me, the properly pitched one seemed “flabby”.
What was the OG of the Amber? Also, what type of aeration was used? There are definitely a lot of factors at play when it comes to ester production, so although it is always a good idea to pitch “enough” healthy yeast, it would be interesting to know what other parameters were used in this specific case when looking at the results.
Nice experiment and, even better, a detailed write-up of how you arrived at your conclusions. The large number of tasters who were not able to tell a difference or preferred the underpitched beer reminded me of my Kraeusen skimming experiment. But for that I did not have as many tasters as you had.
One thing to note, which I also noticed in other pitching rate experiments, was that underpitched beers don’t necessarily end up being more estery and fruity than beers pitched with more yeast. There is a lot written in home brewing literature that suggests that underpitching leads to fruity beers.
Kai
I agree completely with this. I often cite Dr. Clayton Cone of Lallemand who says that beers with lower pitching rates should be less estery.
I think sometimes people get confused between “estery” and “solventy”.
Denny, did you see a difference in head retention between the two when you did your tasting?
The OG was 1.059, and they were aerated for 10 minutes using an aquarium pump and plastic air stone. The recipe and notes from the actual brew session are in the first post.
He noted better retention in the control.
(Sorry to answer for you, Denny!)
I appreciate it, Sean. That way I don’t have to dig out my notes!
Based on this experiment, would you consider making future brews without a “proper” starter?