The other day while reading around the mashing and sparging process I came across the word vorlauf. The meaning was unclear from the context. Is vorlauf a substance, a condition, or an activity? Is it good or bad? Also, how do I pronounce it?
It's an activity and the initial part of the sparge. Definition from BYO.
"At the start of the lautering process, you should use a quart container to catch the first runnings. These will be cloudy and have bits of husk in them. Pour the cloudy, husky material back into the top of the lauter. This process is called vorlauf, a German word that means temporary. The mash materials will act like a filter and clear the runnings."
While draining the grain bed settles and compacts making for a natural filter to keep the smaller bits out of your finished wort. May take a few times but it will start running clearer after the first one or two times.