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Old 12-02-2011, 10:38 PM   #1
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Default Yeast Overpitch/Underpitch Experiment From a Microbiologist

...at brooklyn homebrew! they just started doing classes and the last one caught my eye. it's since sold out so i'm happy i got my ticket early. this experiment will test the effects of overpitch/underpitch, we will be the guinea pigs!

"The experiment will based on the following criteria:

Beer style: Blond ale. I chose a blond ale because any off flavors will have little to hide behind.
Yeast strain: Wyeast 1056. I had a tough time choosing the yeast. I could have gone with a very expressive yeast to detect changes in flavor. I eventually went with a popular strain that many brewers use for their batches.
Every sample will be treated the same and the test batches will be fermented in 1 gallon batches. The original gravity of the beer will be 1.046 and only one hop will be used (see recipe below).

Samples:

Control pitch: 0.75 million cells/ml/º Plato – 32.9 billion cells.
Overpitch: 2.5 million cells/ml/º Plato – 112.8 billion cells.
Underpitch: 0.1 million cells/ml/º Plato – 4.7 billion cells.
The recipe (4.5 gallon batch to be split into 1 gallon fermentors):

7 pounds 2-row Pale malt
1 pound of Carapils
Mashed in at 153ºF for one hour. Raised temps to 168ºF for mashout and recirculated as usual. First runnings at 1.063. Second runnings at 1.018. Collected a total of 5.9 gallons at 1.034. Boiled for 60 minutes:

0.5 oz of Centennial at 60 minutes.
0.5 oz of Centennial at 0 minutes (flameout).
Whirlfloc and yeast nutrient at 15 minutes.
Cooled to 62ºF and pitched the amount of yeast noted above. I did not oxygenate the wort in any sample. Fermented cool (62ºF) until fermentation slowed then slowly ramped up to 70ºF.

On December 14th the class is scheduled and I will post the results, including flavor and fermentation profiles. I’m also thinking of polling the students to see how each beer scored."

http://sciencebrewer.com/2011/11/29/...te-experiment/

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Old 12-02-2011, 10:57 PM   #2
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Subscribed

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Old 12-02-2011, 11:01 PM   #3
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I'm still new to brewing and haven't put too much thought into this, should be very interesting!

Two Beer or not Two Beer

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Old 12-02-2011, 11:04 PM   #4
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Subscribed...

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Old 12-02-2011, 11:16 PM   #5
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yep... I wanna know

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Old 12-02-2011, 11:23 PM   #6
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Cool! Subscribed. .1/mL/plato seems like a pretty significant underpitch.

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Old 12-02-2011, 11:28 PM   #7
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i'll take notes and come back with any impressions. thanks for the interest!

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Old 12-02-2011, 11:34 PM   #8
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Very curious about the over pitch, especially with a neutral 1056... As started before, .1 is a but extreme for an underpitch... But we ll see! Subscribe!

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Old 12-02-2011, 11:43 PM   #9
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Subscibed, definitely curious to see what differences come about in this one!

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Old 12-02-2011, 11:43 PM   #10
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I'm curious to hear your results.

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