Let's get straight on with the description.
This method is mostly common in Altbayern. In Munich the following method is employed. The ground malt is tipped into the mash tun, which already contains cold water. And, while being regulalrly stirred, is left to stand for 3 or 3 hours. Meanwhile, the rest of the mash water is brought to the boil. This is introdusced into the mash tun from below. When all the water is in the tun, the temperature should be 31-37º C. Then the first Dickmaisch is transferred to the kettle and boiled. As soon as the grains begin to rise due to the vigorous boil, enough Dickmaische is returned to the mash tun, whilst mashing all the time, to raise the temperature to 47-51º C. The second Dickmaische is then transferred to the kettle and quickly brought to the boil and boiled for 45-60 minutes. When moved back to the mash tun, the temperature rises to 60-62º C. After standing for 15 minutes, most of the Lautermaische is transferred to the kettle and boiled for 15 minutes. When returned to the mash tun, the temperature of 72-75º C is reached.
The amoount of Dickmaische which needs to be boiled varies greatly. The size of the mash tun also plays a role, because of how it cools down. This is an example for approximately 1000 kg of malt.
4700 l of cold water are put into the mash tun. A further 2150 l are heated in the kettle, of which 1600 l are put into the tun. Temperature 35-37º C. 2550 l are removed from the mash tun for the first Dickmaische and brought to the boil in the kettle. After boiling for 45 minutes, enough Dickmaische is returned to the mash tun to raise the temperature to 47-50º C. For the second Dickmaische, 2600 l is boiled for 60 minutes in the kettle. During this time, the underback is half filled with Lautermaische. As soon as the second Dickmaische has been returned to the mash tun and a temperature of 60-62º C achieved, the Lautermaische in the underback, topped up with the same amount from the mash tun, is transferred to the kettle and boiled. In total, 6000 l are put into the kettle and boiled for 15 minutes. When returned to the mash tun, the temperature is 72-74º C. Brewers put great stock in hitting precise temperatures in the mash tun. For example, the rise in temperature of the mash from 33.75º C at Einteigen to 53.75, 64 and 74-75º C in the Dreher brewery in Schwechat next to Vienna has been copied by many breweries, who believe it to be the secret of the Vienna brewery's success.
I'm pleased to finally see a mention of an Austrian brewery. Very few details of Austrian brewing of this period have come my way. I've just ordered an Austrian brewing manual published in 1914. Hopefully that will help fill some of the many gaps in my knowledge.