Bottled beer in the 1950’s – Bright Bottled Beers (part thirteen)

How exciting. The beer is finally about to be filled into bottles. But not quite yet.

Though it usually didn’t go directly to the filler. There was one final tank for it to sit in.

“After filtration the beer passes to the filling machines, either direct or via a bright beer tank. In some cases a small ballast tank is used between filter and filler; this serves to give a margin of safety for interruptions in either process and compensates for any lack of synchronization. Some filters have an arrangement for recirculation of the beer should there be a stoppage in the filler.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 344.

Makes sense. If the filter and filler weren’t running at the same pace, you’d have problems without some sort of intermediate storage.

As with everything else in the brewery, the filler required thorough cleaning:

“If sterile filtering is relied upon to give beer which will have an adequate shelf life, then the filter and all plant subsequent to it will need very careful sterilization. The mains between filter and filler and the filler itself need very thorough sterilization with a flow of hot liquor (180º or higher) for 15-20 minutes. This can be passed through filter and mains to the filler. If the filler is suitable for steam sterilization it should be steamed thoroughly for 15-20 minutes, but not all fillers can be steamed and in such cases hot liquor has to suffice. In between bottling the mains should be thoroughly cleaned from sludge and deposit, and whenever there is a long interval, such as over the week end, it is an extra safeguard to fill mains and filler with a solution of an antiseptic such as one of the quaternary ammonium compounds, which are very effective.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, pages 344 - 345.

Sterile filtering saved you the trouble of pasteurisation. The downside was that everything after the filter needed to be sterile. Not just clean, but sterile. Any trace of bacteria could cause havoc with the beer in the bottle.

But at least you could run scalding water through the filler. Bright beer tanks were trickier:

“The bright beer tank presents a rather more difficult problem for sterilization. Some tanks are so constructed and positioned that they can be steamed out to a sterilizing temperature, but in the majority of cases tins is not possible either by reason of their construction or because an excessive amount of steam would be necessary to raise the temperature of a vessel in a cold room, and if the tank is not separately heat-insulated the temperature of the cold room might be affected. ”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 345.

Sadly, it wasn’t usually that simple, seeing as bright beer tanks were mostly in cooled rooms. In which case only the chemical option was left:

“Therefore most bright beer tanks have to be chemically sterilized either by filling them or spraying them with a solution made of hypochlorite or quaternary antiseptic. Special attention should be paid to the cleanliness of all tanks to be used as bright beer tanks (unless the beer is to be subsequently pasteurized), particularly with respect to deposits around internal fittings, paying particular attention to the rubber washers on the fittings and to the manhole rubber. The latter should be replaced if it becomes cracked or porous and should be removed each time after use and given an antiseptic soak. Where internal fittings have not been dismantled for a long time it is a wise plan to strip them completely, clean up any sludge or deposit, and renew the rubber washers. Special vessels should be kept for bright beer, never being used for unfiltered beer. Finally, the rinse water used after cold sterilization should be free from infection; sometimes this may need to be chlorinated at not exceeding 0.5 p.p.m., although many bottlers would object to the use of chlorinated water for this purpose, on the grounds that it might flavour the beer.”
"Brewing Theory and Practice" by E. J. Jeffery, 1956, page 345.

Blimey that sounds fiddly. And all you need would be for one employee to sneeze on one of the bits and you could be buggered. With some many different bits to worry about, and the need for sterile rinsing water, there are loads of places it could go wrong. And you’d only need one to infect every bottle.

I had been thinking sterile filtering was a good idea. Don’t think I’d try it in a brewery of mine. Not that I’ll ever have one. I’m far too lazy and broke for that.

As I said above, loads more to come. Next, special instructions for filtering Stout.