So it is a method of making glucose. How does this affect the flavor and fermentability?
Well, according to the "Brewing a Wheat Beer with Intensive Banana Aroma" by Michael Eder in the May/June 2010 Zymurgy, "The greater the difference between the glucose and maltose in the wort, the more ethyl- and isoamyl acetate will be produced by the yeast". Basically, it's accentuating the banana in favor of the clove.
I want to get the 4-vinyl guiacol or clove like phenol. An acid rest at 111F helps to produce ferulic acid which helps promote 4VG upon fermentation.
F. Nitzsche
Investigations into Optimizing Wheat Beer QualityBrauwelt, Vol32, 8 Aug 1991
•The taste and smell threshold is 0.8 mg of 4VG/L
•4VG levels over 2 mg/L bring a strong/severe character to the beer
•The fact that the levels of ferulicacid can fluctuate widely in malt can effect the levels of 4VG in beer
•As a rule, wheat malt has less ferulicthan barley malt
•The highest levels of 4VG occur after the final limit of attenuation is reached
•More 4VG is present when the final limit of attenuation is reached in 4 days as opposed to 2 days
•The levels of 4VG don’t decrease significantly with the age of the beer, although other staling by-products may cover up the taste of 4VG
Here's an intersting paper on German Wheat Beers.
Pitching rate and ferm temp are critical for producing that classic German profile in this beer:
Dr. Narziss
16thTechnological Seminar at Weihenstephan1983
Fermentation
•Pitching Rate 12-18 million cells/ml
•Starting Temperature 12-15 C (lower starting temps more common when starting tank is used to settle cold truband then transfer to fermenterbefore start of fermentation where free rise occurs)
•Max temperature 18-22 C
•Main fermentation is 2-4 days
•Maximum Cell count is 60-80 millionBottle Conditioning
•Lager yeast is less likely to autolyzeand settles better
•If top-fermenting yeast is used, shelf life should be limited to 4-6 weeksFermenterShape
•Cylindrical tanks produce only 2/3 the esters of shallow open fermenters
•Horizontal tanks perform like open fermenters
http://www.mbaa.com/Districts/MidSouth/presentations/Wheat_Beer_Yeast__Fermentation2.pdf