Brewday: Hefeweizen (Glucose Experiment)

Zymurgy had an great article in the May/June issue on brewing a Hefe with serious banana aroma. Well, Summer is here and I had the inclination: banana up my Hefeweizenation. The gist of the article is that by mashing low; low low, like 104 in a thin-mash low, you set up both the right pH and right temp to make the most of the maltase in your mash. In theory this will cause the enzymes to favor certain sugars, namely glucose, which the yeast will use later on to make an increased amount of isoamyl acetate, the ester we describe as 'Banana'. Hence: super banana hefe.

Well the original mash program I designed was a quick acid rest at 86, followed by a thick-decoction heated to 145, added back into the main mash shooting for 104, then heating the whole thing to 162 and 172. Complicated, considering I can't directly heat my mash-tun.

Then it hit me, the whole point of this is to increase the amount of glucose in the mash. What if I added glucose? And glucose is just Dextrose, which I have in abundance from sausage making. So I made a modified mash involving a 20 minute Ferulic Acid Rest (clove spice!) at 113, then a sacc mash at 152, mash out at 168. Add a half-pound of dextrose in the last few minutes of boil for (theoretically) increased banana. Much, much easier.

Gravity ended up low low low, efficiency below 70%. So I added 12 oz of Light DME to spike it back up. Pulled a quart or so of the wort and boiled the DME in it for 15 min. Then cooled and pitched. Wheat. Sheesh.

So here it went:

Recipe: Ninnygeddon Hefeweizen

Est 1.048. Act. 1.041 (corrected back up)
Est FG 1.011
ABV 4.5%
Est IBU 12
Est SRM 5

• 5 1/2 lbs Wheat Malt
• 2 lbs Pale Malt
• 1/2 lb MFB Special Aromatic
• 4 oz Caramel Wheat Malt
• Rice hulls added at knock out, a few handfulls.
  

Mash in with an infusion to 113. Infusion to 152. Infusion to 168. Water mods were 1 tsp Calcium Chloride, 1/4 tsp Epsom Salts, 1/2 tsp chalk. This should buffer the mash but also provide enough calcium for the yeast while making a chloride/sulfite ratio that enhances the flavor. Add another half tsp of chalk into the mash to balance out the hardness and the calcium during the boil.

60 minute boil

• @60 min - Sterling (pellet) 5.3% AA
• Yeast nutrient at 15
• 1/2 lb Dextrose added last 10 min
  

Cool as best you can and pitch a hefe yeast. I did the Bavarian Blend, Wyeast 3056. I'd try to cool to 62, then let it raise itself to say 68. Cooler temps favor clove, warmer banana. This should balance the banana/clove. Unfortunately it was summer and my groundwater cooled to 70, so I managed to ferment a bit cooler but not as cool as I'd like. Don't ferment a hefe like a Belgian. Keep it cool. And 10 days or so max, then bottle. Don't bother with a secondary, keep the chunkies in solution.

UPDATE August 13, 2010