Thursday, 12 February 2015

Gelatinisation of a Nation

I've been getting ready to do brew my next lambic brew so I've been reading up on gelatinisation again as I'll be using Gain Feeds whole wheat that I bought from my local Glanbia Farm Shop in Rathcoffey. When using raw cereals (wheat, oats, or even potatoes) in brewing a cereal mash is required to release starches which can later be broken down into sugars by enzymes during the sacchrification rest in a regular mash. This is done using water and heat to break up starch granules. The minimum temperatures for common adjuncts are
  • Barley: 60-65°C
  • Wheat: 58-64°C
  • Rye: 57-70°C
  • Oats: 53-59°C
  • Corn (Maize): 62-74°C
  • Rice: 68-78°C
  • Potato: 57-65°C 

Wikipedia defines it as so:
Starch gelatinisation is a process of breaking down the intermolecular bonds of starch molecules in the presence of water and heat, allowing the hydrogen bonding sites (the hydroxyl hydrogen and oxygen) to engage more water. This irreversibly dissolves the starch granule in water.

You can bypass the cereal mash by using flaked or torrified grains as they've already had their starches exposed.

I stumbled across a few YouTube videos showing the starch granules physically breaking up during gelatinisation and releasing their contents. If a picture speaks a thousand words...

Potato lambic anyone? There's an idea.

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