Optical oxygen sensor for brewing applications helps to minimize waste of beer and reduce maintenance costs with rapid and accurate measurement of dissolved oxygen. The residual oxygen level has become a key factor for beer quality. Optical sensors set a new benchmark in oxygen monitoring resulting in compelling beer quality and longer shelf life. The optical oxygen sensor will substantially improve the product quality in breweries. Based on a chemo-optical technology the new high-end sensor offer significant advantages, requiring minimal maintenance and calibration effort, leading to long-term stability combined with high accuracy. Calibration in the lab or at the filling line, easy opto-cap replacement and “Plug and Measure” functionality make the handling of the sensor easy, quick and safe.