I am designing a hefe recipe with 3068. Wyeast states under pitching will give you more ester/banana flavors. What would classify a controlled under pitch? Do I just need to try things and see what I like? I don’t want to under pitched too much. Would a 10% under pitch be enough?
Who knows? Pitch rate is a pretty uncertain way to control esters.
It is all trial and error based on your perception… 10% is a good starting point
Than what is? I was under the impression yeast choice would be the best way to control it.
Well 3068 is going to give you an acid reaction to create 4vg (clove). You need an acid rest in your mash at 110-133F for your Ferulic Acid Rest. Then if you are into a DF step mash or a step mash in general you can take your pick of moving to protein, alpha, beta, and mash out. If not jump to your single infusion temp and mash away. 3068 will give you banana no matter what you do, the balanced clove will come from the proper acid rest, and pitchrates IME.
Generally, fermentation temp. Yes, to a degree you can control the ester profile with pitching rate, but as you point out who knows how much to get how much?
I can’t say I’ve used 3068 yet. However, assuming it’s much like any other hefeweizen yeast, I’d ferment at 70 F, and that way you’ll get your banana. And with an underpitch, maybe even more. For a serious underpitch, I’d use 1/4 the mrmalty.com recommended amount. So when he says you need like 2.5 liters for 5 gallons, screw it and just pitch a fully (or even just half?) swollen smackpack without any starter and it should turn out to your liking.
So far I’m a believer in underpitching as a viable means of awesomeness in hefs and Belgians. However, my experiments are yet to be run this summer in this regard. I’m sure I’ll be surprised by something along the way. So, proceed, with caution.
Good points. It’s so hard to control yeast counts. I think Denny is on the right track. Temp is a way easier variable to control.
Has anyone run a side by side comparison of underpitched vs normal pitched for this and truly detected enhanced ester formation in the underpitched batch?
Try as I might, I can’t wrap my head around how underpitching could lead to more esters produced, given that underpitching should mean more cell division, a process which will use acetyl-CoA for lipid production (and hence not for esterification). If anything, underpitching in my mind would result in lower ester production (note I’m not saying that underpitching wouldn’t lead to undesirable effects, I’m just wondering about esters in particular).
I say this as from an academic standpoint, not as someone who has ever done a spilt-batch comparison, hence my question.
Thanks guys.
As a proponent of the Acetyl-CoA theory, I agree with you.
Now what happens if we skip cold side aeration/oxygenation – boil vigorously, then very gently rack the wort into the fermenter, and pitch on top of that. I’m not saying this is a good idea, I’m just saying I don’t know what it does. And most of us probably don’t. 
I haven’t done a side by side but I’ve used 3068 a lot. It’s my go-to hefe strain. I can say from experience that, at least for me, underpitching will noticeably increase the banana ester (isoamyl acetate). My starters sit on stir plates in a flask with a foam stopper, for ~24 hours. If I pitch a 1 L starter (per 5 gal) of 3068, I get very little banana; it’s pretty much all clove and it tastes like a Belgian ale. If I pitch 0.5 L, I get enough banana to balance the clove, much more true to style and much better IMHO. In theory, direct pitching a smack pack should increase the banana even more, and I’ve tried this but the beer never seems to turn out as well (hence the value of starters). The science behind underpitching yielding more esters is that when you underpitch, it will take longer for the yeast for reach their maximum cell density in the wort, and it’s during this time that the majority of esters are formed. Underpitching means that more of everything will be made, including the banana ester. As for temp, yes higher temp will increase the banana, but in my experience the best results are obtained at about 68. I think that for this strain, the underpitching is more important than fermenting at a higher temp.
Basic Brewing Radio did a show where, IIRC, 3068 was pitched at three different rates and compared. One of the underpitched beers was preferred.
The yeast section in “Brew like a Monk” is a great summary of how pitch rate, fermentation temperature, etc. affects final beer flavor. I believe it’s Chapter 8.
Clove is a 4-vinyl phenol, not an ester…
I like the taste of yeast poop.
I’ve found that pitching a single smack pack a few weeks old is a good under pitch. Don’t make a large starter for a Hefeweizen, it turns out quite bland.
It’s odd, but I don’t make a starter, don’t particularly oxygenate, and hold the fermentation at 62 and I’ve had good results.
I did a multi-step mash as well acid, protein, beta, alpha.
I swear, my best hefs were the ones I made like the above in like 1999 when I didn’t know how to brew at all.
That’s done a lot. However, I’m super skeptical as to whether the extra effort does a dang thing to improve the beer one iota.
Same here in my experience (for a 5-gallon batch). Starter = bland hefe, 1 smack pack with no starter = flavorful hefe. I confirmed this years later when I moved to 2.5 gallon batches. One full smack pack led to bland hefe’s again. Cutting to half of a pack brought back the flavor.
Similar experience here. Smack pack on stir plate = bland. 1 smack pack no stir plate = much more flavorful.
In 5 gallons