Monday, 14 November 2016

Cold liquor tank working well.... just in time for Winter!

Well, we knew this was going to be the situation we found ourselves in, and in many ways it's quite amusing.... and in other ways quite annoying.....

It concerns our major project this year, the cold liquor tank, which would have been ideal to have been in service during the summer and autumn when mains water runs warm.  So what, you may say, who cares what temperature the water coming out of the tap is?  What does that matter?

Well, to that I'd say shut up and listen.....  most small brewers use mains water to power their plate heat exchanger (PHE or paraflow in brewer's parlance) which is a terribly useful and also quite mysterious device which takes in water and hot wort from the copper at one end, and spits out hot water and cold wort at the other.... quite how it does it remains a mystery to me (yeah, yeah, I could look it up but that would spoil the mystery, and I know the basics anyhow) but, and here's the crux of the matter, the PHE can only cool wort to "pitching temperature" (around 22°c for us, we run off warm then use the chillers on the FV to bring the temperature down to 18.5°c) at a speed governed by the temperature of the water coming in which, in Autumn, can reach almost 20°c which can mean running off 1500 litres of wort to FV can take almost 2 hours at a pitiful 12 litres a minute which means it's scarcely dribbling out of the aerator!

So, in steps our flashy CLT (cold liqor tank) which solves this problem by using a chiller unit to cool water stored in the 3200 litre bulk milk tank via a coiled copper tube immersed in said water.  This resulting cold water (at around 5°c rather than mains at over 10°c) means the PHE can cool the wort much faster and has reduced the 1500 litre transfer time down to 40 minutes or so, a massive saving in time and much less standing around for us....

However, as you'd expect, in Winter the mains water starts to become a lot colder and the water can - in Jan and Feb in particular - be entering the brewery at around 6 or 7°c which means we don't really need the CLT!  Saying that, at present it's bringing our cold liquor down to nearly 5°c which is very impressive and means, for now at least until the weather gets really cold, we can transfer in just over half an hour at 37.5 litres a minute!  

Wednesday, 2 November 2016

Cask "deep cleaning"....

Giving something a "deep clean" is a somewhat trendy thing to do these days for reasons unknown, but if it's good enough for hospitals and kebab shops then it's good enough for Hopcraft towers and our stock of casks!

For the past 3 years we've followed the cask washing mantra of...

1) steam clean cask with 130 degree steam from the Karcher
2) visual eye / nose inspection of cask
3) if it passes, then it's taken inside for filling (rinsed with peracetic first)
4) if it fails, then it's washed again, tested again, and if it still fails the residue / rancid aroma test then the cask will be filled with caustic solution and left to sit for a few days before being emptied, rinsed and inspected again.... 

Before being filled with beer the casks are peracetic rinsed to sterilise them and flushed with CO2 to hopefully evict as much oxygen as possible to prevent staling in cask.

Now, however, we've added an additional step after the cask is brought inside for filling of giving every cask, if possible, a kegbrite wash followed by a water rinse.  Kegbrite is a chemical which is designed to remove hop residue and other baked on crap from inside casks - and if you've looked inside as many as I have you'll know how much potential for crap there is inside casks - which can only, hopefully, improve our final product's stability and shelf-life further.

So, the policy of "permanent revolution" rumbles on, pushing it's nose into all aspects of the brewing process, and I for one welcome it.... and so should our customers with better beer leaving the brewery!