/* Primary Fermentation */
Primary fermentation starts when yeast is added to the [[wort]] right after the [[boiling]] and [[cooling]] steps. Once the yeast is added, we call the mixture beer as opposed to wort. The primary, or active fermentation process typically takes 3-5 days during which the bulk of fermentable sugars are converted into alcohol and CO2. During this phase, CO2 production is strong, often producing a foamy head on the top of the beer.