IN-HOUSE NITROGEN
Blockbräu brewery in Hamburg uses self-generated nitrogen
24 · BBII 6/2020
PRODUCTION
reaching the final degree of fermentation,
a two-day diacetyl rest
is done to avoid a high concentration
of this metabolic product
of yeast and the taste errors it
causes. To mature the beer, the
tanks are then cooled to 1 degree
Celsius and left for a period of
up to 6 weeks.
After maturation all contact with
oxygen should be meticulously
avoided, otherwise oxidative reactions
can take place that could give
the finished beer a broad and
bread-like taste. In order to empty
the fermentation and maturation
tanks, the interior is therefore filled
under pressure with a gas mixture.
The mixture consisting of 50 percent
nitrogen (N2) and 50 percent
carbon dioxide (CO2) is pressed
into the cylinder from the top,
which expels the oxygen out of
the tanks while the beer flows out
at the bottom. Before filling with
the next batch, the tanks are first
steam sterilized and then rinsed
several times with nitrogen.
From the storage tanks, the beer
continues its journey to the various
stainless steel serving tanks. These
are pre-charged with the same
N2-CO2 gas mixture. In this way,
the necessary counterpressure is
built up to prevent the pressurized
beer from foaming and also to
avoid the negative impact of oxygen.
From the four stainless steel
served for seasonal wheat beer,
which delighted customers in summer
2020 with a fresh flavor and
aroma of banana and citrus fruits.
In winter, the menu includes the
Weizenbock – an amber-colored,
naturally cloudy strong specialty.
Another tank is reserved for the
legendary Senatsbock, which is
brewed according to traditional
recipes as a collaboration beer with
seven other Hamburg breweries.
Oxygen, the enemy of beer
In the unitanks, which are used in
the tanking process both for fermentation
and maturation, the wort
of two batches is blended. After
three days of fermentation without
pressure, the tanks are pressurized
so that the natural fermentation
CO2 can bind in the beer. After
The Blockbräu is to Hamburg
as, say, the Hofbräuhaus is
to Munich. The brewery with the
spectacular view of Hamburg
harbor is also a tourist magnet
and a place of refuge for locals.
With room for 450 people on
3 levels and a further 400 seats
on the sunny harbor terrace,
Blockbräu is a restaurant and event
location in one. But it isn’t only the
panorama and copper brewhouse
in the guest room that draws the
guests but above all the excellent
beers that are brewed here. Under
the direction of brewmaster
Thomas Hundt, about 5,000 liters
of lager, wheat beer and Senatsbock
are made here each week –
that’s almost 300,000 litres per
year. The Senatsbock and the newstyle
Hefeweizen took two awards
in 2019 in the Meiningers International
Craft Beer Award and
the European Beerstar.
Taste and quality are everything
at Blockbräu. In the brewhouse,
under the watchful eyes of the
guests, Hamburg brewing water,
hops and malt are used to create
the wort, which is then placed in
the fermentation vessels. In seven
tanks with a volume of 4,000 litres
each, this is then cooled to 12-22
degrees and left to ferment. Four
of the tanks are used to pale lager
beer with an hoppy note, which is
attributed to the aromatic Hallertau
hops. Two of the tanks are re-
for better taste stability
Blockbräu has won several awards for its beers in recent years. The brewery
with adjacent dining experience takes the finest ingredients and innovative recipes to
create finely matched flavors for its various kinds of beer, thrilling thousands of visitors
every week. To retain the aromas, the brewpub in Hamburg’s premier location by the landing
stages on the river Elbe uses nitrogen in the brewing process and for filling bottles and kegs.
The flavour and aroma as well as the character and quality of the beer can be ensured through
the environmentally friendly use of nitrogen. A nitrogen generator produces the necessary
protective gas directly on site affordably and in an environmentally friendly way.