Under Pitch.

[BlackDuck]

Since there is a thread about over pitching, I thought I was start one about under pitching. Today, at lunch, I was reading an article in Craft Beer & Brewing magazine. It was about a small brewery in Albuquerque, NM called La Cumbre Brewing Company. http://www.lacumbrebrewing.com/ It was specifically about their Elevated IPA, which is a 2011 GABF Gold Medal winner. In the article, the owner/brewmaster says this regarding his pitch rate:

"We pitch 400 million cells per milliliter per degree plato, or 40 percent of the recommended amount to pitch" he explains. "We achieve a faster, healthier fermentaion by pitching a little less yeast."

Later in the article it is mentioned that because it is a fast healthy fermentation that "Elevated is a 10- or 11-day beer", compared to most IPA's that are made in two weeks.

Things that make me go Hmmmm. Maybe I need to try to pitch one packet of yeast when BeerSmith tells me to pitch two, and maybe I need to crash and bottle mine a lot quicker than I am currently doing. The great thing is that the magazine gives a recipe converted down to 5 gallons. May just have to give this a try.

[russki]

In the voice of the XX guy: I don't usually underpitch, but when I do, it's for a Hefeweizen...

When you underpitch, you make the yeast throw a lot more esters/phenols during the growth phase, which is desirable in certain styles, and not so in others. I personally would never underpitch yeast for a beer where I want a clean profile, but for yeast-driven styles, I do it all the time. I've never made a WY3068 starter - it gets pitched directly to get lots of .

[BlackDuck]

I'm right there with you russki, that's why I was a little perplexed when I read the article. The article says he uses American ale yeast. If only I could get some of this to try it (JimH...are you listening???). Hell, he won a gold medal at the GABF with it, it must do something right.

[Beer-lord]

I'm pretty sure when I started brewing again after a long break that I under pitched a number of times and didn't like what I tasted. I'd have to agree with russki that in most instances, you don't want to do that.

[mashani]

An under pitch *will* fully ferment your beer unlike some folks will tell you. That is as long as your wort contains enough oxygen and nutrients to fully support the extended growth phase. I under pitch some beers intentionally - IE Wheats or Belgians or Saisons where I want the extra esters/phenols from the extended growth phase.

[BlackDuck]

I'm with you guys too....I've heard of under-pitching for certain style like Belgians, Saisons, etc. too. And I would also be worried about over stressing the yeast and causing undesired off-flavors.

But it's hard to argue the technique when a small commercial brewery has taken a gold medal at the GABF with a beer (that was NOT a Belgian, Saison, etc.) that was purposely under-pitched.

I left the magazine on my desk at work. If I have time tomorrow, I'll post the recipe and the directions.

[mashani]

Think about it this way... a small amount of fruity esters might not be noticeable as such. But they could provide a "fullness" or "roundness" of flavor over a beer where they were not there.

My thoughts are basically that every yeast strain is different, every beer is different, and even in a "clean" style finding the elusive perfect flavor you are looking for in a beer you make repeatedly and are trying to perfect (if that's your thing, it's not really mine) is a balancing act of all the ingredients. If everything else is as good as you can get it and you can't seem to find a way to improve it any more, messing with the pitch rates could be something to try to see if you can kick it up a notch. That might mean pitching more or less. There isn't a simple answer that would cover all styles of beer or all strains of yeast.

[John Sand]

A couple of thoughts: Pitch rates, like hopping, are a "science". But so is weather forecasting. An IPA may have enough strong flavor from hops to hide any yeast flavors. On the other hand, pitch rate calculators and package instructions are not always consistent.
Last year I made a Belgian Strong, OG was about 1.080 or above. I pitched one vial of yeast (WLP530), a significant under-pitch by any published standard. When judged at a BJCP event, the beer was deemed to have insufficient esters, the opposite of what was one might expect. When I brew it again, I'll "under-pitch" again. I expect a similar result, but who can say for sure? I think that pitch rate is a valid consideration, but I concentrate more on temperature control.

[BlackDuck]

but I concentrate more on temperature control.

Interesting that you say that. I do know that the recipe was very specific on temps. Pitching temps and fermentation temps, and I even think it had dry hop temps.

Now I will make time to post the recipe tomorrow. Stay tuned!!

[mashani]

RE: Temps - that really also depends very much on the yeast. WLP530/3787 (Westmalle strain) will work over a wide variety of temps, and to get the best ester/phenol profile like the best commercial or for sale out the door of the abbey beers made with that strain you really (imho at least) need to pitch it in the mid-upper 60s and then let it ramp up to 78 or even 80 degrees during fermentation, but then let it slowly fall back into the lower 70s or upper 60s again after it stops blowing your fermenter lid off. This strain doesn't mind being underpitched/stressed, it's really hard to make bad beer with it, it's beastly in its fermentation characteristics. Wide temp fluctuation during fermentation actually makes better beer, but it will still be good if you hold it stable. And even if it hits 82, 84 it's still going to make beer you can drink. It is perhaps my favorite yeast on the planet.

Now if you do that with WLP500 (Chimay strain) you will get banana flavored nailpolish beer, which is not so nice. If you underpitch it too much you also can get banana flavored nailpolish beer. It likes a more stable temperature range and has a smaller temperature range where it makes good beer (that tastes Belgian) - is best I think between 68-74 - if it goes much over 75 it can get really nasty really fast. I would not let it go over 74 unless you have temperature controlled fermenter that can lock it at 74-75, and you do want some banana (but at least not nailpolish). And lower then 68 you may as well not be using it if you want it to taste like a Belgian. And if you are going to ferment at 74-75 with it, you really should make a starter and pitch it appropriately, or be pushing your luck with the banana flavored nailpolish...

[John Sand]

Thanks for the report, Mash. That batch also got pretty hot, 84 or above. (The strip only goes to 84) It's good to know. The beer came out well, scored decently, some people love it. When I use it again, I'll add gelatin, as it doesn't settle well on it's own.

[BlackDuck]

So here's the recipe straight out of the magazine, it was converted to yield a 5-gallon batch with 72% brewhouse efficiency.

OG = 1.070
FG = 1.015
IBU's = 100+
ABV = 7.3%

Malt/Grain Bill
10.75 pounds Canada Malting Superior Pilsen malt
1.2 pounds Rahr wheat malt
.55 pounds Durst Munich II
.55 pounds Hugh Bairds Carastan (30L)

Hop Schedule
1.75 oz Columbus @ FWH
1.25 oz Columbus @ 30 minutes
1 oz Chinook @ 15 minutes with 1 tablet Whirlfloc and yeast nutrient
1 oz each Centennial, Chinook, and Columbus @ flameout
1 oz each Simcoe, Mosaic, Centennial, Nelson Sauvin and J-17 at dry hops (6 days)

Yeast
Your favorite American ale yeast

Directions
Mash at 150F. Sparge with 168F hot liquor. Boil for 90 minutes. Cool to 66F and oxygenate to 12 ppm. Pitch the yeast and let ferment for 5 days, raising the temperature to 72F by day 4. On day 6, rack to secondary with dry hops. Let sit on dry hops at 70F for 3 days. Crash to 32F on day 4 and add silicic acid (sold as Biofine Clear) on day 5 and let sit for 2 days. Transfer to keg and carbonate to 2.5 volumes and serve as fresh as possible.

Notes
J-17 is an experimental South African hop. It is woody with notes of blueberry. Galaxy, Waimea, Rakau, Riwaka or Dr. Rudi could substituted.

I know we have talked a lot about Belgian style yeasts being under-pitched in this thread, but they use American ale yeast for this IPA. I am guessing the yeast nutrient and the oxygenation would play a huge part in the success of under-pitching this type of yeast.

[mashani]

The nutrients and oxygen will allow for proper healthy yeast growth up to the intended levels when active fermentation begins. So yes if you are trying to duplicate that recipe, then you do want to oxygenate as described.