I just got back from Dusseldorf, home of the Dusseldorf Altbier. Man I love altbier. I think I drank every one in town including Schlussel, Shumacher, Fuchschen, Gatz, Eurige, Frankenheim, and perhaps others.
When at the Eurige brewery, I was introduced to one of their on-duty brewers. I was quite surprised to see he was an american, and formerly a homebrewer from North Carolina. I asked many techinical questions and tried to get a yeast sample but, sadly, Eurige is very closed-mouth about all of this. No tour or anything. He told me that I was the first person to ever ask for yeast (hefe) since his arrival there 2 years prior.
Fuchschen's policy apparently is quite different. The on-duty brewer there came out to greet me and 3 of my friends. He was very friendly and chatty, and determined to answer any questions I had with as much english as he could muster. His name was something like Ollie ( but with a long Ō ). He took us through the restaurant and down into the brewery, and then described the brewing process there. This was interspersed with frequent samplings of very fresh beer straight from the brighting tanks. Absolute blast.
Unfortunately, I was not prepared for this kind of tour (I was just on a mission to get a yeast sample), so I failed to ask many relevant brewing questions. I did learn that they do multiple induction steps in which they fire the oil burner below the mash tun to raise the temp through several steps (they do NOT do decoctions). They use about 90% pilsner, 2% carafa, some accidulated malt, and some other minute grain additions that he didn't mention (in his words, he though they were unnecessary but the master brewers insisted on adding them). The mash tun was the standard large copper job, and there was some sort of SS mixing bar in the bottom. When we were there, there was water with a gypsum addition sitting in the bottom of the fermenter.
Their mash process takes about 2.5 hours, then the wort is pumped to a large lauter tun tank. Don't know much about that, or the subsequent boil. They do a single 60 minute hop addition of Tradition. They use both pellet and hop extract (which I embarrassingly stuck my fingers into). No late hop additions.
Initial fermentation is in large stone open fermenters. They were covered with hugh frothy yeast krausen; there was absolutely no protection from bugs. You'd have to see this to believe it (see video links below). Initial fermentation is only 2 days, but considering the huge amounts of fresh krausening yeast they used, I believe the fermentation is that quick. OG ~10°P, transfer from initial fermenter to large SS tanks at about 4°P, where the beer continued fermenting until about about 2°P. These are pressurized tanks, with a relief valve set to about 1 bar (15psi). I think he said the beer sits in these tanks for 10 days.
Ollie talking with us
They do their own kegging, but I believe the bottling was done elsewhere (could be wrong on that). They have an impressive robotic filling system for the different keg sizes. All of the kegs I saw were some sort of plastic: I didn't see a single SS keg over there.
At the end of the night, we went back up and got a bunch more beer. Our server, Dirk, and Ollie sat with us and we had fun for several more hours. Real blast.
Altbiers and my Yeast Sample!
Note that bottle of yeast in the pic above. I brought that back, and it's growing right now on my stir plate. Will be brewing a big batch of altbier this Thanksgiving weekend. Woohoo.
Here's some lively videos from our visit to the brewery. Video is from my iPhone, so please excuse the quality. I think the only one I'm in is kneeling next to a SS pot of yeast (my coat went right into it, on the floor).