Real-time measurement of diacetyl in beer Real-time measurement of diacetyl in beerThe flavor of beer is strongly influenced by the presence of diacetyl and 2,3-pentanedione. Owlstone's Lonestar analyzer can detect and measure levels of these two vicinal diketones (VDKs) in minutes, right on the brewery floor. Offering detection down to 30ppb (parts per billion) and the ability to measure total diketones or free diacetyl, the instrument is ideal for early fermentation monitoring and finished product quality assurance.