What is the process of drawing wort from the bottom and pouring it back on top in brewing?

The process of drawing wort from the bottom of the mash tun and pouring it back on top is known as vorlauf. This step is critical in the lautering process, where the wort is separated from the spent grain after mashing. The purpose of vorlauf is to clarify the wort by allowing suspended solids and other particulates to settle and be removed before the wort is collected for boiling. By recirculating the wort over the grain bed, the brewer helps establish a clearer run-off, which leads to a cleaner final product.

In the broader context of brewing, recirculation does occur during the lautering process, but it is a term that can apply to various steps throughout brewing and may not refer specifically to the initial clarification process. Lautering encompasses the entire sequence of draining the wort from the mash tun and may include vorlauf as a specific method for enhancing clarity, highlighting why vorlauf is the correct answer in this context. Fermentation, on the other hand, occurs after lautering and is the process where yeast converts sugars into alcohol and carbon dioxide, which is unrelated to the processes involved in separating wort from grain.