Tuesday, September 21, 2010

The Brewing Process

Hi Everyone,

It's been a few weeks, and unfortunately no real progress has been made on the installation of our brewing system. But we have confirmed that a friend who has installed a drain or two, will be helping me break the concrete and install the long awaited drain on October 2nd. It'll be a long day but well worth the effort!

In my last post I mentioned that I would post a P&ID of the system, so here it is (well sorta):

 Any real process engineer would laugh at the thought of calling the above drawing a P&ID but for this blogs purpose, I think it's adequate. If you'd like a more in depth look at the brewing process have a look here: http://en.wikipedia.org/wiki/Brewing and if you're really nerdy buy this book: The Prctical Brewer  (or you can borrow mine).

A few notes about the drawing: The "Auto Sparge" is a float system that allows Sparge water to automatically be added during the second phase of the Lautering process. The valve to the right of the Transfer pump is used to bleed off any air before we start the pump, as this type of pump will not run dry. All the valves on the system are manual, but maybe in a couple years I'll automate them and run this system by computer.

Onto the description:
In our home brewery we will be doing all grain brews, which is why we need the Sparge Tank and Mash-Lauter Tun combo tank. The Sparge tank will hold brewing water at a predetermined temperature (notably 45°C, 62°C and 73°C depending on the grains). We will mill the grain (which grain will depend on what type of beer we're making) and put it into the Mash Tun, then add water from the Sparge tank. All three of the above tanks sit on natural gas burners and they have thermometers so that I can heat up and maintain the desired temperatures.

Once the Mash Tun is to temperature enzymes will be activated and it will take from 1 to 2 hours for the  enzymes to convert the starches of the grains to dextrins and then to fermentable sugars such as maltose. Once we have Mash, we will start the Lautering process.

Lautering is the separation of the wort (the liquid containing the sugar extracted during mashing) from the grains and moved to the Brew Kettle.The separation process has two stages: first wort run-off, during which the extract is separated in an undiluted state from the spent grains, and sparging, in which the extract which remains with the grains is rinsed off with hot water from the Sparge Tank. The false bottom of the Mash-Lauter Tun has holes small enough to hold back the large bits of grist and hulls. The bed of grist that settles on it is the actual filter.

Now that the wort is in the Brew Kettle we'll crank up the heat and bring it to a vigorous boil. Once boiling, we'll add our hops at different stages and in varying quantities to get the desired flavors, bitterness and aromas. When the boil is complete we'll pass the wort via the Discharge Pump through the 2 Stage Filter and then through the Heat Exchanger to drop the temperature of the wort quickly to a fermentable temperature. From here we'll transfer into our 14.5 Gallon conical fermenter, add some yeast and let fermentation run it's course.

I'll cover aging, filtering and carbonation in another post, once we've actually made some beer! My next post will be about the final stages of the installation, then onto brewing.