Beer Stability and Free Recipe!

This week we're being taught by Dr. Michael Zepf from Munich. He's an extremely smart guy who did his thesis on beer gushing. Shown in this picture is Danny enjoying a litre of Pils, not Dr. Zepf. The Germans would not like the lack of foam on Danny's beer.

"There is no such thing as beer stability. When you age wine and it slowly turns back into grape juice. When you age beer it slowly turns back to wort. Which would you drink?"

Some of the problems with beer stability are the trends in the market towards longer travel of the beer, lower flavor, lower "light" alcohol beers. Although this is not true for the local handcrafted "malternative" beer, it is definitely a trend of the large and some of the craft breweries.

The precursors for staling (lipids, high alcohols) are effected by temperature, oxygen, light and of course, time. Different free amino acids, through the Strecker degradation reaction to form "aging carbonyls". Aging carbonyls are described as having a "sweet, moldy taste". These aging carbonyls through yeast reduction are then reduced to higher alcohols. It's the aging or "time" factor that effects all beer. Through aging and oxidation the higher alcohols and other factors, that our yeast buddies spent so much time producing, go back to the aging carbonyls. That's what Dr. Kepf meant by beer being turned back into wort. Fresh beer has a crisp, dry and bitter taste. Old beer looses bitterness and becomes more sweet and finally turning to a cardboard flavor.

Although Dr. Zepf employs decoction mashing on all of his beers at the brewery, he suggests not to on lighter beers. Lipoxygenase is denatured at 60C, and he suggests mashing in at this. However, he won't stop decoction mashing out of tradition. Why change a winning team?

Here's a little Amber Hefe recipe I came up with in honor of him:
O.G. 12P. around 20EBC about 14BU
for 12 gallons treat water to match Munich or at least 100ppm Calcium
50% Wheat 4EBC 10lbs
40% Munich 16EBC 8lbs
10% Carahell 24EBC 2lbs
.5% Carafa Special II 900EBC 2oz

(edit. mash in for ferulic acid rest at 45C and apply heat to mash to 60C before continuing.) Mash at 60C. Pull large decoction after 20 min. Iodine test decoction before denaturing enzymes. Add small portion of decoction to raise mash to 65C. Hold for 10 minutes. Add rest of decoction to raise to 72-75C for mashout.

Boil with lowest burner you have, not vigorously for 6o minutes! Add 13BU (1oz)of German Perle extract or pellets at 40 min, add 1 or 2 BU (.5oz)of German Tettnanger pellets at 10min. Whirlpool, chill and ferment at 17-19C (edit. ferment at 20C)with Wiehenstephan 68(Wyeast 3068). Bottle condition and serve at breakfast with sausage and pretzels.

BTW after we finished the sierra nevada pale and 312, we finished kegs of fat tire, two kegs of Great Lakes dortmunder, Three Floyds Gumball head, and another sierra nevada. Yeah us!