Increasing the Clovy and/or Banana Flavor of Wheat Beer
One of the greatest beers of choice for summertime is the refreshing wheat beer. Some people prefer their wheat beers to be clean and clear, others prefer the phenolic characteristics of banana and/or clove. Here are some tips to allow you to produce the wheat beer which accentuates the characteristics you prefer.
When designing your wheat beer recipe a minimum of 30% wheat is recommended. When using wheat extract, keep in mind that wheat does not mean 100% wheat malt. Alexander Wheat Extract is 60% Wheat and 40% Klagas and Muntons Wheat Extract, both syrup and dry, is 55% Wheat and 45% Barley.
The choice of yeast, wort composition, and fermentation conditions will all affect the production of phenolic characteristics.
4-vinylguaiacol or that clovy phenolic flavor is produced when suitable amounts of the precursor ferulic acid (FA) are present in the wort. FA originates in malt and can be achieved in high concentrations by mashing at 104° F. Decarboxylation of FA to 4-vinylgauacol occurs slowly during the boil, so increasing the boiling time to over 100 minutes will positively influence this reaction.
The banana flavor desired in some types of wheat beers comes from the ester isoamyl acetate. The concentration of esters is influenced by a number of factors including, pitching rate, wort gravity, aeration, and wort composition.
The wort concentration of isoamyl acetate can be increased by increasing the glucose concentration of the wort. This may be done by adding Dextrose (corn sugar) to the wort on an average of 1 ounce per gallon. The ratio of glucose to maltose may be increased by using a decoction mash.
Under pitching and fermenting at the upper temperature range stresses the yeast which increases the production of phenolic characteristics including the production of isoamyl acetate. The yeast may also be stressed by not providing it with sufficient oxygen during the respiratory phase.
Choose yeast for your beer that has the propensity to produce the characteristics you desire. Clove-like characteristics are readily produced by Wyeast #3068 and Lallemand Munich Wheat Beer Yeast while Wyeast 3638 Bavarian Wheat and Lallemand Munich Wheat Beer Yeast produce more isoamyl acetate or banana esters.
If you desire a clear beer or Krystal Weisen, use Irish Moss in the boil and a fining agent like Gelatin or Isinglass which remove yeast following fermentation. For a hefeweizen omit the use of Irish Moss in the boil as well as Gelatin or any other fining agent which removes yeast.