- May 14, 2014
- Reaction score
Whoever authored that analogy doesn't know very much about diffusion. Diffusion processes typically proceed at rates inverse to the square of the diffusion distance. If you have to diffuse twice as far, then it takes four times as long. There are multiple diffusion processes involved in a mash. Water has to diffuse into the surface of the grain particles, the starch has to gelatinize/solublize, amylase enzymes convert the starch to sugar, and sugar has to diffuse out of the grain particles into the free wort. This all proceeds from the outside of the grain particles towards the centers. The larger the particles, the longer the process takes. So, a mash with smaller particles will complete faster than a mash with larger particles."Crush: Crush fine as this will allow more rapid and more complete wetting of the grains allowing very high mash efficiencies. One prior poster states that a fine crush is phooey yet immediately states they double mill. They are therefore using a fine crush. You can use a blender if you have one."
Nice try. Double or triple milling doesn't give you a finer crush. It makes sure that all your grains are crushed open. A good analogy I've heard is a grain is like a packed suitcase. All you need to do is crack open the suitcase and expose the material inside. It is unnecessary to take what's inside and grind it up too. The double crush makes sure that every suitcase got popped open. To get a finer crush, you would need to decrease the space between the rollers.