Wednesday, 3 February 2010

Brewday: Expanding A Few Points.

I'm brewing again today, so I have decided not to do another as live blog as it would be pretty much identical as yesterday, making it pretty dull reading. Instead, I will elaborate and explain some things I glossed over in yesterday's blog that might have had you scratching your head or opening another browser tab to google it.

Firstly you might have noticed there is no reference to water either hot or cold anywhere. The term brewers always use for brewing water it 'liqour' I'm not really sure why, possibly to make sure in the brewery that there is no confusion and mixing of cleaning and general purpose water with that for brewing.

Secondly, I mention I add DWB to the malt while it is in its sacks before mashing in. DWB is powdered gypsum, better known as plaster of Paris. Almost all breweries will add a little of this to alter the levels of dissolved salts, minerals and other ionic compounds in their water. This is done because some water styles suit certain styles of beer. Burton is the most famous example of this, the local water which is very high in minerals and salts makes amazing pale ales. London and Dublin, both famous for their stouts and porters have relatively soft water. For this reason adding compounds to brewing liqour is sometimes known as 'Burtonising'.
I also mention something called wort. Wort (pronounced wert) is what brewing liquor that has been added to the malted barley in the mash tun is called. It is sweet and sugary and tastes a little like Horlicks or Maltesers.

I also mention something called a heat exchanger. This is a vital part of the brewing process. It takes hot wort from the copper and runs it through a series of plates which look a little bit like belgian waffles. Sandwiched in between these plates cold liquor is pumped in the opposite direction. What this does is sends cold liquor in one direction, heating it up as it goes and sends hot wort the other direction cooling it as it goes. The individual plates are waffle textured to maximise the surface area in contact with the cooling. This is also used as a money saving technique as the hot liquor coming out of the heat exchanger ends up in the hot liqour tank, reducing the amount of time the elements need to be on for the next day's brewing.

To clean stuff around the brewery we use dilute caustic soda as most breweries do. Caustic cleans stuff but it doesn't disinfect. For this we use peracetic acid at 200ppm. It takes about 15 minutes to completely kill any microbes living on things so forward thinking is always needed, anything touching the wort after the boil in the copper must be sterilised first.

Any other questions, feel free to ask! And to the the cheeky person who emailed (you know who you are) yes, I do listen to radio 4 in the morning, but I switch to BBC 6 music at work. In answer to your second question, tea at work is PG tips, milk, no sugar, drunk from a plain blue mug with no design or logo.


  1. Another interesting entry, nice one. Never ceases to amaze me how commerical brewing is so close to home brewing ... just bigger!

    Is there any reason why you add the water treatment to the malt and not the liqour? In home brewing, it always seems to be added directly to the liqour.

    That blue mug looks like it could do with some caustic itself! :P

  2. I use a 1% caustic soda solution at 60-80 deg C to clean and sterilize the fermenting vessels. I was told by the rep from AB Vickers that peracetic acid does not sterilize unless it is used in a stronger solution than is recommended.