What is burr mixing?

Answer 1

I was wondering the same thing, so I did a bit of googling and here's what I found:

The Burr Mixer: The Burr Mixer is the industrial version of those small hand-held "stick" blenders used to make individual frappes or perhaps soy milk-shakes in the glass. In size and power, the Burr Mixer is about 10 of these stick blenders put together. The Burr Mixer is often orange or a stark gray in color, resembling a piece of equipment one may see on a construction site. When used, usually to make hefty amounts of pureed soups or sauces, one cannot help almost crying out "arr, arr, arr," like Tim the Toolman Taylor from the re-runs of Home Improvement. Burr Mixer caution: refrain from using this tool to make mashed potatoes. Trust me.

Here's where I found this: http://www.babblog.com/Jan_05/010405_KF_Food.htm