Intentional Underpitching

[jman300sd]

I'm planning on doing a Franziskaner Heffe clone this weekend and wanted to get everyone's thoughts on the best way to treat the yeast. For the record I do want the heavy esther and phenol bananaramic funk flavor. From everything I have read on here the best way to achieve this is by underpitching, but I'm not really sure of the best way to do this. I'm probably going to use a wyeast 3638 smack pack.....should I just pitch 3/4 of the pack in 3 hours after smacking?

 

[weirdboy]

According to Yeast by Chris White and Jamil Zainesheff, underpitching does not in fact improve ester production. That has more to do with fermentation temperatures.

EDIT:
However, they do say that pitching too much yeast can result in lower ester production.

 

[ghpeel]

There's some dogma out there that under pitching Hefe's & Belgians results in more bana funk, but I'm not sure I buy it.

A friend of mine makes great easy-drinking Hefe's pretty frequently by just chucking a tube of WLP300 into wort (no starter) and walking away (no temp control). Her beers come out fairly clean, with a nice acidic character, almost a little tangy and a little Belgiany. Delicious!

I myself just kicked a keg of Hefe with WLP300 too, but I had a big starter and a proper fermentation fridge. My Hefe was a lot more "German", more Banana/spice character despite having a starter and cooler fermentation temps. Delicious as well!

So to summarize, I'm not convinced about the pitching rate impact on the final beer.

 

[theredben]

According to Yeast by Chris White and Jamil Zainesheff, underpitching does not in fact improve ester production. That has more to do with fermentation temperatures.

EDIT:
However, they do say that pitching too much yeast can result in lower ester production.

Logic dictates that there is some relationship between underpitching and increased ester production, just maybe not 1:1. Maybe underpitching by 1/2 increases esters by 5% or something (just making up numbers), which would make it not worth it for other associated reasons.

 

[Homebrewtastic]

Make a starter. Add 1 droplet of olive oil to it. That increases ester production.

You also get better ester production the more generations you get out of it. By about the 4th or 5th you start to get some really great banana esters.

 

[El_Exorcisto]

http://www.mbaa.com/Districts/MidSouth/presentations/Wheat_Beer_Yeast__Fermentation2.pdf

These guys seem to have the numbers saying that underpitching does in fact increase ester production... It's a study done involving several German hefe breweries.

 

[kanzimonson]

Any possibility you could split the batch in two and try two different pitch rates? Not enough people are doing experiments like this.

I've also heard (on HBT, someone quoting Fix) that overpitching can produce more esters, which is against most people's common logic. I believe the reason cited was when you overpitch, the yeast have to use less nutrients for reproduction, so instead they use it for some of their other activities that produce estery byproducts.

In any case, I'm a big supporter of proper pitching rates but I think you should try an experiment.

 

[Homebrewtastic]

Read this. This is the study done on adding olive oil to yeast starters.

Under pitching stresses out the yeast. They have to duplicate more. This equates to more esters.

However it's never a good idea to under-pitch your beer. And it's ALWAYS a good idea to make a starter. If for no other reason than to ensure that you have healthy and active cells. Just because you're making a starter that doesn't mean you have to make a huge one. You can make a small starter to ensure overall health of your yeast, and just not make a big one to help with the banana esters.

 

[jman300sd]

As this is only my second batch ever, I'm not entirely up to doing two batches just yet. Though, I do like the idea of experimenting using two (or more) batches of the same wort under the exact same conditions, but with different yeast applications. Perhaps a few batches down the road. If I do end up doing it, I'll definitely post it here.

Interesting paper on the use of Olive Oil. I think it's something I'm going to try. Will report back.....gonna be getting a starter going this Thursday.

Also....whats the logic behind subsequent generations of yeast producing more esters?