hopback
A sealed chamber between the brewing kettle and counter-flow wort chiller, into which hops are added.
hopback: settling tank that filters and cools wort at once
A hopback is a cylindrical or rectangular vessel positioned between the kettle and the wort chiller in a brewery. Its primary job is to separate spent hops and trub (break material) from the hot wort flowing out of the kettle, while the wort cools slightly in the same pass. The vessel typically holds 50 to 200 liters on a 10 to 20 barrel system, scaled to match your kettle volume.
The device works by slowing wort velocity as it enters the hopback chamber. Whole hops, leaf fragments, and coagulated proteins settle to the bottom or form a natural bed that acts as a filter. The clear wort flows over a weir or under a dip tube and exits toward the chiller, leaving behind a compact layer of hop solids. This design avoids the need for a separate hop screen and reduces the risk of chiller blockage, which is critical when using whole-leaf hops or high hop rates.
Temperature drop is modest but real: wort cools roughly 5 to 15 degrees Fahrenheit in transit depending on chamber size and residence time. The hopback does not replace the chiller, but it complements it by doing rough filtration work and beginning the cooling process. On some breweries, especially those using pellet hops or with tighter kettle strainers, the hopback is optional; on others, especially those brewing high-hopped ales with whole flowers, it is essential equipment.
Most hopbacks use a simple gravity system: the kettle outlet valve controls flow rate into the vessel, and the wort bed depth controls back-pressure. A false bottom or sintered strainer plate sits above the discharge, supporting the hop cake while allowing liquid through. Some designs include a rinse or recirculation valve for re-sparging the hop bed at the end of the run, reducing sugar loss. Larger commercial hopbacks may have an external pump inlet to keep wort moving and warm.
The main failure mode is channeling: if wort flows too fast or unevenly, it punches through the hop bed and carries solids into the chiller. Slower vorlauf (running off clear wort) at the start, gentle kettle valve openings, and proper hop loading prevent this. Spent hops and trub from the hopback are usually hosed out to waste after brew day, though some brewers compost or repurpose the material.