BREWHA Equipment Co Ltd. BIAC, User Manual

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your supplier do it for you). A general width guideline is 0.04–0.048”/1–1.2mm. If you still have
a problem, go slightly wider. If you are experimenting with gelatinous or gummy cereals (e.g.,
oats or rye), you can include rice hulls to help counteract the ‘gummy’ effect and keep the bed
fluid. Also, using a good grain mill to crush your grain evenly is important. We recommend the
Crankandstein 328G (fully geared 3-roller mill) and have found the factory setting (0.045”) to
provide a good size for fluidity and conversion.
Second, when doing a single-step mash, if the strike temperature is properly calculated, it is
not critical to pump the wort during mash and it can be simpler not to. With the Mash Colander
inserted in the fermenter, it is effectively surrounded by a water bath that will help maintain the
temperature. The element keeps the water bath at the target temp for mashing and warms the
colander, which warms the mash. When mashing is almost complete, the pump can be operated
to move the water under the colander to the top of the grain bed for vorlauf. While care still
needs to be taken, during vorlauf it is less likely that your mash will stick or that you will run out
of water in the cone portion of the fermenter where the element is, especially if the next step is
followed.
Third, if circulating during the mash or during vorlauf, if the water level starts to rise in the
Colander, it means wort is being pumped out of the bottom faster than it is being replenished,
and the pump outflow should be slowed (in time, if the flow is not slowed, the element will be
exposed and could be damaged). To prevent the pump from moving wort too quickly, a valve
must be installed on the downstream side of the pump (either on the pump outlet or on the
Mash Colander port) and partially close it to slow the amount of wort being circulated. (Don’t
close or restrict a valve BEFORE the pump in any way, as this ‘starves’ the pump and can damage
it.) If grain that has fallen through the Colander plugs the pump line, momentarily open the valve
wide to move the grain into the Mash Colander or attach the pump intake line to the cone side-
racking port, rather than the bottom port of the fermenter (although if possible, it is better for
uniform flow through the Colander to keep the pump line connected to the bottom port).
Fourth, with the Power Controller, power output can be set to around 20-30% during mash,
which is typically more than enough to maintain mash temperature while minimizing the chance
that the element will be ruined if temporarily exposed.
Note 1: Throttling the pump (by partially closing a downstream valve) is also the best way to
prevent pump cavitation. Cavitation occurs when the pump is pushing liquid out faster than it
can draw it in. This creates a vacuum, which causes a ‘cavity’ to form, which prevents efficient
operating of the pump (a screeching sound from the pump is most often caused by cavitation).
When the flow is throttled back on the exit side by partially closing a valve, it prevents liquid
from being pushed out faster than it can be drawn in, preventing the cavity from forming.
6
BIAC User Manual Safety
Caution: A ‘squealing’ sound in the pump often indicates a cavity, in which
case the pump should be turned off immediately. See more information in
‘Installation’ section.