Thursday, April 12, 2012

Beer on the Move - How to transfer beer from FV to Conditioning Tank, Road Tanker or Filter.

Here's a shot I took at a well known Czech brewery, which is famous for the 70 day maturation or lagering of its beer. The hoses coming from the right into the mixing manifold are taking the beer from two 200hl (121 barrel) horizontal cellar tanks to the filtration room through the manifold, which in Czech is called the nanny-goat, because its looks like the goat's udders (!). The beer then goes to the pump in the background and thence off to the filter buffer tank. The wooden beck or large bucket is there to take the overflow from the bleed-off valves on top of the sight-glasses via the small red hoses.

Whereas back at Inveralmond Castle, you can still see the red hoses, albeit with a smaller bore, with the beer coming out of FV8 (Big Bertha) through the sightglass then into the pump and off to the filter assembly. Below there is a similar set up - Conditioning Tank (CT7 - Bigger Bertha, 120 Barrels) valve on left, sightglass, T-piece with CO2 line and 1/4"gas valve then beer hose to pump. Our pump is known by its more prosaic name 'Big Pump' -  two stage centrifical pump for those with an interest in such things, which works by an impeller spinning around inside the stainless housing at the front (the blue rear is just a huge heavy motor) and this impeller flings via centrifugal force the beer up through the outlet on the top of the pump off to its destination. Imagine you were spinning a bucket of beer around your head at 1500rpm and there was a small hole in the bottom of aforesaid bucket - how far would the beer spurt out and more importantly, who would clean up afterwards? But that's simply how centrifical pumps work.    

You'll be asking yourself why the sightglass and T-Piece with CO2 valve, I am sure. Well, the sightglass is to show when the tank is empty and when we're getting to the bottom we watch it like a hawk, as we don't want to send too much yeast or tank bottoms that have sedimented out during the cold-conditioning of the beer off to the filter or to the road tanker, which latter will be going off for bottling. The Co2 line is there to flush the whole Transfer Line or Tx line with CO2 all the way to the destination tank/er, which has its own T-piece, to push out any remaining sterilant (in our case peroxyacetic acid, which is a harmless terminal, ie no rinse needed, sterilant) and most important of all, any oxygen to the drain.
Oxygen, essential to yeast for growth and any successful fermentation, is to be avoided and excluded as much as possible after fermentation as it oxidises, not oxygenates, the beer to cause rapid staling and unwanted off-flavours in the beer. So the CO2 flush is a must before bringing the beer down the line and the first part of the beer goes to the drain first before opening up simultaneously the tank inlet/T-piece drain valve. Below you can see the tanker rear for Ossian from yesterday. Bottom right is the beer line in with the valve handle, then the T-piece with its drain valve closed, and the fittings leading from the 1&1/2 inch line to the 3inch tank inlet valve. On the left is the drain line now attached to the tanker overflow line with its valve out of view, which controls the top pressure in the tanker. We like to fill tankers at about 1 bar top pressure to prevent any fobbing of the beer as it's filling, and to assist in this beer tankers always have a pressure gauge on the overflow line.     

When the tanker is just about full, beer fob or foam will flow down the drain line and when it turns to beer, the tanker is full. Overflow valve off, Tanker inlet valve off. Pump off. Close off beer line valve and disconnect and then wash down with sterilant, close up back door, seal up and send tanker on its way.

With moving beer between FV and Conditioning Tank, the principle is the same - sterilise the CT with the Tx line and pump with peroxyacetic (1/2% solution v/v) first, then drain, take off plug of yeast in FV, connect up sightglass and CO2 T-piece to FV outlet, flush TX line downstream through pump into CT with CO2 to create a blanket of CO2 within the CT to protect the beer form air and oxygen, then close off CO2 line and then open up FV outlet, so that the rough beer can flow down the line into the CT. We let the beer flow into CT as much as possible under gravity but eventually we'll switch on the pump to complete the process as beer doesn't like flowing uphill often! When the FV is empty or the pump starts to suck out the yeasty tank bottoms, it's shut off the pump, close off FV outlet and then use the CO2 to push the last aliquot of beer in line through to CT and then close off CT inlet and CT overflow line, gas off and disconnect gas line. Disconnect beer line from CT, wash down CT valve with sterilant and then connect beer line to drain to allow the cleaning of the FV to place. Have cup of tea, or, in extreme cases, to celebrate another succesful Transfer of Beer retire to a Place of Sanctity and Sanity and enjoy a fine glass of beer, like Aleš below, from aforesaid well-known Czech brewery who celebrates his name day (svátek) tomorrow on April 13.

Na Zdraví & Slàinte! Ken