Tuesday, 24 June 2008

Augsburg method of decoction

I told you that I hadn't forgotten about lager. Distracted. That's what I was. Time for the Summer of Lager again.

This is another decoction method, loosely translated from pages 125 to 127 of "Handbuch der Chemischen Technologie: Die Bierbrauerei" by Dr. Fr. Jul. Otto, published in 1865.
For 100 pounds of malt 600-700 pounds of water are used.

Einteigen occurs with cold water. Very often, though, another method is used. Some hops are sprinkled on the bottom of the mash tun and the grains put over them. The cold water is then poured onto the grains without being worked in. The hops are to stop the smaller parts of the crushed grain falling through the holes in the bottom of the tun and to prevent souring.

After Einteigen, the mash is left to stand for 4 or 5 hours. The liquid which has gathered below the false bottom of the mash tun is drawn off. This liquid, called Satz [sediment or deposit], contains loose parts from the malt, including protein. When the water in the kettle boils a few Maaß of Satz are added to the kettle and the water is boiled for another half hour or so, depending on how hard or soft it is. The protein from the Satz helps remove impurities. The scum is removed.

The purified water is added to the mash and mashed. The temperature should now be 60-62.5º C. The mash is left to stand for 15 minutes.

The water is added slowly to the grains so that the temperature doesn't rise too quickly. Many brewers take a break at thus point to allow the grains to soften completely.

When enough water has been drawn off from the kettle for the first mash, the remainder of the cold Satz is put into the kettle.

The first wort is drawn off into the Grand [no idea what this is] and from there put in the kettle.

Of the clear wort, about 15 to 20 Maas isn't boiled, but quickly cooled. The wort, called the warm Satz, is later, before the boil with hops, reunited with the rest of the wort. The use of warm Satz makes the finished beer milder and clearer by encouraging a more powerful fermentation. The quality of the warm Satz determines the quality of the beer. It should be crystal clear and have a pure, sweet taste. The quality of the malt can be judged very precisely from the Satz.

Usually only about two thirds of the wort is drawn off and slowly brought to the boil. Any scum is skimmed off. (Lautermeisch.)

The boiled wort is put back into the mash tun and mixed with the grains, raising the temperature to 62.5 - 65º C. The mash is stirred vigourously to ensure a gradual rise in temperature.

After mashing, the thick part of the mash is transferred to the kettle. The Dickmeisch is brought quickly to the boil, whilst being stirred continuously so that it doesn't burn. It is simmered for one hour. Signs that it has simmered for long enough are: when no more scum is formed, when a test sample of the liquid quickly clears.

After sufficient simmering, the Dickmeisch is added back to the remaining thin wort in the mash tun and mixed well. Constant agitation helps separate the large and small particles and so helps obtain a clear wort.

If there is a second Lautermeisch, which is unnecessary and not usually done, the wort is drawn off immediately after the Dickmeisch is added back to it. This clear mash is brought to the boil and then immediately added back to the mash tun, where it is left to rest for 60 - 90 minutes.

The Satz is put into the kettle and the hops added to it. The wort is slowly drawn off (so that it is perfectly clear) and added to the hops and and Satz in the kettle. This is slowly brought to the boil.

To extract the remaining sugars from the grains, cold or hot water is poured over them. The wort so extracted is not usually used in Sommerbier, but used instead to make a weak beer. Some of this weak wort is used in Winterbier.

This method is most used in Schwaben, though quite often without warm Satz. Brewers fear problems with unboiled wort in warm weather.
Next is the Franconian method. After that, who knows. I may go modern, if the latest version of Kunze I just ordered has arrived.

11 comments:

zythophile said...

Is that a picture of a giant lemon-and-meringue pie with the thermometer sticking out of it?

I'm fond of a nice lemon-and-meringue pie, me ...

jakester said...

Good Lord, Ron, that's complicated. Does it say what the benefits are to doing all this? We do single, double, and sometimes even a triple decoction, but it's nothing so difficult as this.

Ethan said...

That's amazing. I like the use of a bed of hops as filter/preservative for the original Saz extraction and Einteigen (acid rest?). I wonder if alpha acids are extracted and isomerized later when it's added back to boil. Certainly about the earliest hopping I know of, though I guess I've heard of hops being added to the brewing water before; Never tried it.

And Jakester's right- what a long, long brew day that would be- is any figure given there? I'm guessing at least 12h.

Ron Pattinson said...

ethan, yup, really long brew day. There wasn't an overall time given so you'd need to add it all up. But why would they go to all that trouble if there weren't some empirical reason?

Ethan said...

Oh, I've no doubt there is some empirical reason... Like I said, very cool.

Jim Johanssen said...

Ethan - I believe the Einteigen is just to wet and soften the dry grain for better extraction, because the acid rest is at about 95F and the cold water in the Texas summer is seldom that hot. Notice that there is no mention of temperature in the description. With decoction one does not need a thermometer, it helps but it is not necessary. The use of hops in the mash tun for a filter bed seems to be very common in Germany and Belgium and may be done to overcome problems designing/building a screen for the mash tun.
Ron - Could the grand not be a grant or underback? The calling the wort “Saz” seems strange, is there a reason that is so close the name for the word for Czech hops Sazz(Saaz)?
The Kunze book is used by several brewing programs (UC Davis, Siebel Institute, and VLB in Berlin) as a text book. My statement about the book being a keeper WAS a gross understatement and like all true text books it is expensive!
Cheers
Jim
PS. Homebrewer , No Beard, No Tats, Khaki shorts
(it’s hot in Texas),
Jeans are for hard work like decoction mashing! ;p

Jim Johanssen said...

Ron - Grand is an Underback

Ref.
"A German-English dictionary for
chemists" pub. 1917
by
Austin McDowell Patterson
Page 127

Love that Google.
Cheers
Jim

Ron Pattinson said...

Jim, they loved to Einteigen. All the old methods have a couple of hours of it.

Looking properly through Otto, he explains what a grand is - a copper-lined receptacle underneath the mash tun taps, sunk into the floor.

Just asked my wife about Saz and showed her the text. It's in a horrible gothic typeface. She suggested it could be "Satz" not "Saz" (even she wasn't sure). One of the meanings of Satz is: dregs, sediment, deposit. I think that explains the word. Apologies for misreading it.

The 1998 edition of Kunze arrived today. It cost me over $100, but it's worth it. I'm interested to see what decoction methods it describes. I'd never realised how many different ways there were to do a decoction. I found another five today. Looks like I'll be writing about it all year.

Jim Johanssen said...

Ron - Thanks for the information. I am trying to understand why they are using satz the way they do and for what result where they are trying to get. I understand the water purifcation part, the rest I am still looking into.
The methods are always facinating to see, and trying understand why is fun.

Cheers
Jim

Ethan said...

Jim,

but, 95 degrees F is actually fairly perfect for an acid rest...?

Jim Johanssen said...

Yes 95F is a very good temperature, but the Bacteria responsible for the acidification are slow and needs to work for more than 5 Hrs, more like 18Hrs or more unless they pitch some bacteria. Most acid rests I have seen are left to work overnight.

Cheers
Jim