developments in cross flow filtration, which has not only modernized the brewing
process, but also reduced the production footprint at the same time. Della Toffola Group
has a long association with the beer industry, supplying diatomaceous filters since the early
1970s to many of the world’s leading beer brands. Over the last twenty years the company
has developed further into a leading manufacturer of processing technologies and
turnkey brewery solutions. Della Toffola has also been at the forefront of cross
22 · BBII 6/2020
FOR ALL SIZES
Beer recovery from lees using
ceramic membrane technology
Amongst the most exciting developments in beer brewing have been
flow filtration development with a focus on ceramic membranes.
the solids concentration can reach
up to 90 percent before the retentate
needs to be discharged.
New filter for beer recovery
from lees
Beer recovery from lees has in the
past been very rudimentary with
few options being available, with
the resulting product generally of
substandard quality. Brewers are
facing stiff competition and the
need to reduce yield losses as well
as effluent, have resulted in Della
Toffola developing a cross flow filtration
solution offering a high quality
filtrate from lees.
Della Toffola’s ceramic membrane
technology is now finding favor
with many breweries ranging in size
from craft brewers to modern large
industrial producers. With the
Omnia B filter beer clarification,
recovery and sterile filtration can
now be achieved with a single filter.
Many advantages such as the
superior mechanical resistance
and ability to withstand aggressive
CIP regimes were recognized as
being very important to brewers.
Della Toffola’s range of beer filters
are all capable of 9 bar operating
pressure with extremely low levels
of dissolved oxygen pickup. They
work at sub-zero temperatures
without filtration flux and are suitable
for the use of processing
agents like PVPP.
Products with very high turbidity
and solids can be processed in
the Omnia B filter in a single pass
Viscosity as critical factor
Cross flow filtration requires a certain
tangential speed over the filter
membrane surface to sweep the
surface clear and prevent clogging.
The speed of the product to be filtered
is governed by a number of
factors, of which one of the most
critical is viscosity. As viscosity increases
during the filtration cycle,
the speed slows and a critical point
is reached where the retentate
must be discharged from the filter.
The smaller the membrane diameter,
the earlier the need to discharge
is reached. With polymer
membranes the critical viscosity
is reached at around 8 percent suspended
solids, with Della Toffola
beer filters this critical viscosity
is reached at around 15 percent
suspended solids and with the
Omnia B filter from Della Toffola
The material from which ceramic
membranes are constructed
is very strong and durable, easily
able to take many thousand CIP
cycles at high temperatures with
no appreciable wear of the membranes.
The lifespan of ceramic
membranes is on average fivefold
longer than the lifespan of polymer
membranes. The effective filter
surface in the ceramic membranes
is between 5 and 8 μm thick, this
very thin layer is characterized by
a high hardness and robustness.
Due to the very thin construction,
particles in the retentate cannot
block the actual filter structure,
enhancing its effectiveness and
prolonging membrane life.
The channels in ceramic membranes
can be constructed in
differing shapes and diameters,
as well as porosities ranging from
nanofiltration over ultrafiltration
to microfiltration. This large range
of possibilities means that the filter
can be customized to a porosity
ideal for the required flavor profile
and to a diameter and shape to
maximize retentate concentration,
and with that, the maximum yield
of product per filtration.
The Della Toffola ceramic filtration
modules normally have a porosity
of either 0.45 μm or 0.8 μm. These
porosities have a more positive effect
on the organoleptic properties
of the finished beer than 0.2 μm
porosities. Polymeric membranes,
on the other hand, are always
around a porosity of 0.2 μm in
order to maintain the mechanical
strength of their membrane strata.
Very compact: The footprint of the
Omnia B filter is similar to the diameter
of a 200-hl fermenter.