I've always attributed it to a sulfury quality from the yeast.
I don't think it is a sulfury character from the yeast. You only get that in cheap German beer like Oettinger for example. It's more likely something that comes from the hops.
Here is a hopping schedule that I found in the brewing text I was talking about:
- 50% of alpha acids 5-10 min after boil begin and 60 min before boil-end. This addition is mostly done as a high-alpha bittering hops or hop extract. Some of this addition can also come from an aroma hop.
- 25% of alpha acids 30 min before boil end. This is an aroma hop addition
- 25% of alpha acids 10 min before boil end. This is an aroma hop addition.
The total alpha acid per hl (100 l) is about 12g for a Pilsner. This is about 0.4-0.5 g alpha acid per gallon. The use of P45 pellets would be useful since that limits the amount of vegetative matter that gets in the boil, but they are not widely available for home brewers.
Obviously this is not a hopping schedule from a commercially available beer but its a good start.
This is interesting stuff Kai. I am thinking the combination of German bred hops scheduled by AA% in a specified ratio of high to low alpha acids in conjuction with the appropriate water chemistry. We might be on to something here.
I found this bit of info in regards to water chemistry.
A survey of beer production around the world will find that softer waters tend to favor the production of lagers and darker ales while harder waters favor the production of paler ale styles with more hop presence.
Here are just a few of the major brewing centers:
Pilzen: With an average of just 7 mg/l of calcium, this is the softest water on earth. The Bohemian Pilsner style tastes very malty, in spite of the higher hopping rates than it's sister, German Pilsner. Widely copied, this style is the gold standard and originator of the whole pilsner family.
Dortmund: The style of Dortmunder is widely misunderstood by brewers and judges alike. With calcium levels second only to Burton-on-Trent this water accents hops and presents a dry maltiness so prized in the Dortmunder style for its balance. Lingering hop bitterness, despite very low IBU's can be directly attributed to the mineral content of the water.
Vienna: While Vienna lager is prized for its malty character, it is also supposed to have a relatively dry finish with a balance of hops. This city also has very hard water similar to Dortmund. As it turns out, nearly the same water profile is available in Mexico, especially Mexico City, where many classic examples of this style continue to be made.
London: Would you be surprised to find out that this city has some very soft water? With calcium levels at about 52 mg/l it has a profile that lowers the acidity of dark malts, leaving porter very round and drinkable.
When geographic differences are lined up, the major factor in brewing styles is water. Water is the one ingredient that can't be imported and yet can be manipulated most by the brewer.