Brewing

During the mashing process the milled grain (grist) is mixed with a specific amount of hot water (hot liquor), to achieve a specific temperature (around 65 °C) and then allowed to rest for a period of time (usually 60-90 minutes). During this rest, Alpha Amylase is activated in the (high) temperature ranges between 68-71 ºC and breaks down starch chains to create more complex sugar chains which are less fermentable and produce “bigger” bodied beer. Beta Amylase is activated at lower mash temperatures (63-67ºC) and breaks down starch chains to simple sugar chains, which are highly fermentable and produce thinner and drier beer. Basic operating parameters monitored during the mashing are temperature and saccharification. In addition to standard methods, sensors exist that include determination of density, conductivity, pH, saccharification, temperature and viscosity. The liquid portion of the mash, known as wort, is separated either by straining through the residual spent grains (lautering) or by filtering through plates (mash filter). Parameters monitored during the lautering are volume and extract (density), which are important for extract yield and optimum composition of wort extract. The wort is then run to the kettle where it is boiled with hop products (wort boiling), usually for one hour. The hops have two principal components: resins and essential oils. The aim of wort boiling is to ensure optimum utilization of hop resins and hop oils, ensuring leakage of sensory undesirable substances and to create the conditions for the colloidal stability of beer by tannin-protein complexes precipitation. Principal components and parameters of wort relevant to it are: gravity (extract), saccharification (iodine number), fermentability (sugar content and sugar spectrum), free amino nitrogen (FAN), inorganic ions (Ca+, Zn+), pH, vitamins, oxygen, flavour precursors (SMM), flavour components (DMS, essential oils, linalool), bitter substances (iso-