- Some Belgian breweries pitch as low as 0.5 million cells/ml/degree Plato, some as high as 1 mill/ml/Plato. Wyeast recommends 0.75 for most ales, so you d beMessage 1 of 11 , Nov 20, 2012View SourceSome Belgian breweries pitch as low as 0.5 million cells/ml/degree Plato, some as high as 1 mill/ml/Plato. Wyeast recommends 0.75 for most ales, so you'd be safe around that mark.
Cheers,Greg FleehartBrewmasterNorthwest Brewing Company
On Nov 20, 2012, at 10:04 AM, Russell Everett <ciacontra@...> wrote:
Both of you are correct. Though we often group them, it's important to remember that phenols and esters are different chemicals from different processes. Phenols can come from many sources, chlorine, bacteria, wild yeast, those are your bandaidy-chemical smells and apart from increasing the potential hospitality of a home for those guys, underpitching wouldn't affect that. But they also come from yeast, for example, 4VG (clove) in hefeweizens is caused by the yeast using an enzyme to break down naturally occurring ferulic acid in the malt. But usually (excluding contamination from wild yeast, bacteria, etc.) esters, diacetyl and fusel alcohol production are byproducts of yeast cell division, and the health and vitality of those old and new cells. If you underpitch, the yeast have to divide more before they start fermenting, meaning more production of those compounds. When yeast settle into the busy business of making us delicious ethyl alcohol they don't produce esters, but when they are struggling to grow they tend to. Basically they use the same co-enzyme to make new cells as they do to make esters. If they use most of it making new cells in the normal healthy manner, they don't produce a ton of esters. But the more they divide the more they use up nutrients, oxygen, etc and they start to struggle, meaning more Co-A for esters. Similarly, the more they divide the more they use up nutrients, oxygen, etc and the weaker the future generations tend to be, so you end up often with higher final gravities and residual sugars. With some strains underpitching accentuates those properties nicely (like in some Belgian and most Hefe strains) but there's underpitching, and UNDERPITCHING. :) Course overpitching brings its own problems. One of which is lack of esters, because there is so much yeast they hit their stride very quickly and just make alcohol.
Mine's at the brewery and I'm at home now but if anyone's got their copy of the Yeast book around I'm sure it's got the answer in it.
On 11/20/2012 9:32 AM, bob yeaw wrote:
Totally off topic, (Sorry Boyd!) but my understanding is underpitching can increase esters, confirmed in Gordon Strong's Brewing Better Beer and wyeast page: http://www.wyeastlab.com/com-pitch-rates.cfmBoyd - Another option is to pitch a fresh vial whitelabs WLP510 along with the 3789. According to http://www.mrmalty.com/yeast.htm this is the Saccharomyces strain used by Orval. The idea here is that you probably still have some brett alive in the smack pack, but the sacc health is suspect. As Nick said, a starter will likely throw the balance of the two off. Pitching a proper amount of WLP510 and adding the 3789 for the Brett strain might help get the balance right.cheers,-bob
On Tue, Nov 20, 2012 at 8:52 AM, Annie Johnson <eastsacbrewers@...> wrote:
Underpitching does not bring out phenolics and which phenolics are you referring to? Fermentation temp combined with properly pitched wort is going to effect flavor more than anything. Considering the gravity of most Belgians, underpitching is not what you want.
If it's an Orval clone, it's a Belgian pale ale fermented and then dosed with Brett.
Mr. Malty is a good reference for a yeast pitching calculator. Brewing Like a Monk and Wild Brews and Farmhouse Ales are excellent book sources for Belgians, as is Julian in our group! He brews them exclusively.
------------------------------On Tue, Nov 20, 2012 8:14 AM PST Kevin Sullivan wrote:
>Wyeast packs are good within 6 months of the manufacture date, most viable within 2. It should still work but make sure it swells and in most cases I would recommend building a starter, althought I've heard more than one person say you want to underpitch Belgain styles because it helps bring out more of the phenolics. You might do a quick calculation on the Mr. Malty site and see what kind of pitch rate Jamil recommends given your OG and yeast MFG date.