Much is very similar to the description in "Die Herstellung Obergährige Biere" published 50 years earlier.
In the DDR Berliner Weissbier is the most important top-fermenting beer, not just for the home market but also for export.
As already stated, Berliner Weissbier is a lactic acid beer. As a result of its high CO2 and lactic acid content it has a good thirst-quenching effect.
The method of production is mostly brewery-specific, which means to say that each firm has its own experience in production, which is handed on from generation to generation. The proportion of wheat to barley can vary greatly, from 1:1 to 4:1. Weissbier is only lightly hopped; it's generally brewed to an original gravity of between 8 and 9º; but sometimes to 12º and more. The mashing scheme is the infusion method.
The wort mostly wasn't boiled, but recently that has been done in order to avoid infection.
The mashing scheme can look like this:
Einmaischen 50º C 10 minutes
warm slowly to 69º C
Saccharification rest 69º C 30 minutes
draw off a third of the mash and boil with hops
Auf- und Abmaischen 76º C
Rest 76º C 30 minutes
After the rest in the Lauterbottich the wort is abgeläuteret and usually boiled for 15 to 30 minutes to strerilise it. Afterwards the wort is drawn off and left in the cool ship for 20 minutes. It's cooled to20-22º C and immediately pitched with yeast. About 0.5 of dickbreiige yeast is used per hectolitre of wort.
Also in this method pitching in a pitching tun is preferred.
To have a guarantee the the yeast begins working immediately after pitching, it's mostly pitched into a barrel with Vorderwürze. At the warm temperatures which are normal for top fermentation, it starts to work quickly. Only when it is fully working are the tuns pitched with this wort-yeast mixture.
The primary fermentation of Berliner Weissbier is conducted at around 18º to 20º C. About two to eight hours after pitching a thick head appears on the surface of the wort. To be able to harvest clean yeast, this head must be removed. This process starts about 6 hours after piching and continues until a clean, fatty-shining yeast layer appears.The harvesting of top-fermenting yeast occurs on the surface of the young beer. As soon as the clean yeast layer appears, harvesting begins and continues until no more yeast is produced.
The beer must be cooled during primary fermentation, but care must be taken not to scare off the yeast. Top-fermenting yeast is sensitive to large drops in temperature and once stopped through great cooling, only restarts working very slowly.
After 30 to 48 hours, depending on the temperature, the primary fermentation is complete. During primary fermentation as much extract as possible is fermented, that is every attempt is made to achieve the highest possible degree of attenuation.
As soon as primary fermentation is complete, the young beer is mixed with about 15% Kräusen and immediately filled into bottles or barrels.
Weissbier filled into transport barrels is delivered to Niederlagen and pubs to be filled into bottles.
Bier filled into bottles in the brewery is lagered there.
Lagering of Weissbier takes place at a cellar temperature of 15º C. If the cellar temperature is lower than 15º C, then secondary conditioning progresses too slowly, as does clarification. When the wort has been sterilised in the brewhouse, then lagering can be conducted at 20º C. The risk of infection isn't as great as with an unsterilised wort.
Weissbier yeast is a mixture, living in symbiosis, of top-fermenting beer yeast and lactic acid bacteria, which multiply greatly during the fermentation process, so that the proportion is about 1:1. The bacteria die during storage also relatively more quickly. The ratio of yeast to lactic acid bacteria changes then to around 4:1. Weissbier yeast cannot be watered or washed because the lactic acid bacteria can be too easily washed away.
The lactic acid bacteria in Berliner Weissbier yeast is not a single strain, but many strains which coexist.
Berliner Weissbier contains about 2 to 3% alcohol and 0.25% lactic acid. The lactic acid content can, however, vary greatly. The colder the primary fermentation, the worse the lactic acid bacteria develop and the less lactic acid in the beer.
As already mentioned, it was attempted to produce a Berliner Weissbier yeast in which top-fermenting beer yeast and delbrücki bacteria were brought together. However, this yeast-lactic acid bacteria mixture did not produce the characteristic Berliner Weissbier aroma. It is also very difficult to accustiom the two types of organism to a symbiosis.
Care must be taken during the production of Berliner Weissbier to prevent an acetic acid bacteria infection. Acetic acid bacteria produce an unpleasant tasting, scratchy sourness. The quality of the beer is through this considerably damaged.
Another unpleasant effect as a result of the infection is ropiness which appears because the beer becomes as viscous as oil on account of of the slimy shell around the bacteria, caused by pediococcus viscosus. Because Berliner Weissbier is usually stored relatively long, this characteristic disappears agaian. The slime dissolves or is broken down by enzymes. However, if it appears in summer, when Weissbier after a relatively shorter storage is packaged, then the cost price is considerably higher, because it's necessary to wait with packaging until the ropiness has disappeared.
Old hands assert that Berliner Weissbier acquires, after it has gone through ropiness, a pleasant, wine-fruity flavour.
In Berlin Berliner Weissbier is also partially stored in tanks. Unlike by bottle-conditioning, the Jungbier does not have 15% but 20 to 25% kräusen added. The tanks are under 2 atmospheres of pressure.
The level of sourness must be continally monitored. Practical brewers measure the amount of sourness by taste alone; in "Stups-Weißen", as Weissbier stored in tanks is called, it is 0.30 to 0.35%. When the lactic acid bacteria have created enough sourness, the tank is cooled to 0º C.
Should you want to give Weissbier an unlimited shelflife, the protein must be removed. Deglutan is usually used for this purpose.
For tank-stored beer, filling is performed using a high-pressure filler. Despite this, the eber must be cold to prevent CO2 coming out of solution and to prevent the beer from becoming wild.
Pasteurisation is out of the question for Berliner Weissbier as pasteurisation gives it a flavour that makes it unenjoyable.