After boiling, the hopped wort is now cooled, ready for the yeast. In some breweries, the hopped wort may pass through a hopback, which is a small vat filled with hops, to add aromatic hop flavouring and to act as a filter; but usually the hopped wort is simply cooled for the fermenter, where the yeast is added. During <answer>fermentation</answer>, the wort becomes beer in a process which requires a week to months depending on the type of yeast and strength of the beer. In addition to producing ethanol, fine particulate matter suspended in the wort settles during <answer>fermentation</answer>. Once <answer>fermentation</answer> is complete, the yeast also settles, leaving the beer clear.
In what phase of brewing does hopped wort become beer? 
fermentation