Monday, August 23, 2010

Roosters HB Class Visit 2010 part 1

Here we are - Roosters Omahu Road Hastings
This is a class trip I arrange each year, after the students have learned enough about wine to appreciate the differences and similarities between brewing and winemaking. Chris Harrison does a great job communicating the story behind his choice to found Roosters in order to fund Beach House Wines.
Raw material - malted barley
Roasted to different toast levels

Malt is milled into the mash tun and water added

Hop flowers dried on the vine over the door
The wort is drained to the kettle and the mash dug out. Here's Darryl.
Here's the mash, off to the cows

So the raw materials - water and malted grain - mix together and the enzymes in the grain convert the carbohydrates in the grain into simple sugars, and then these are leached out into the hot water.

The kettle boils the wort, and hops are added
The boiling sterilises the wort, denatures the proteins so they can settle out and also extracts the aromatic and bittering components from the hops that are added. The hops are added early on for maximum extraction, though some styles of beer require a second, late hop addition to increase the aromatics in the beer - India Pale Ales and Pilsener are examples of a late-hopped style.
The wort is cooled as it is pumped into the fermenters, with yeast and oxygen
Heat is recovered from the wort by the plate heat exchanger, and returned to the water tank for tomorrows brew. The wort is reduced from 100 deg C to 15.
Fermenters, cooled to 15 deg C for lager, 22 deg for ale
Fermentation takes about a week, a little longer for the higher alcohol styles. Alcohol content is determined by the level of fermentable sugar in the wort, (like brix in grape juice) and can be increased by putting more malt into the mash tun at the beginning, or decreased by adding more water.

mmm, beer...

The ferment is quite vigorous, depending on the yeast and temperature.

Filter cleans up the green beer that has finished ferment and settled for a month in conditioning tanks

Diatomaceous Earth filter - also used for wine production. Clarifies the beer once it has sat for a month in the chiller tanks to settle and mature. This conditioning process is called Lagering but is not exclusive to lager styles.

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