In preparation for the SBR article on Lautering (the most complex part of brewing with respect to process and liquid-solids handling) a glossary of key terms. Glossary of Mashing/Lautering Terms. Copper: This is a term sometimes used for the kettle in a brewery plant in which wort is subjected to a controlled process of boiling. Darcy’s law: This is a law and equation originally derived by Henry Darcy in the 1850’s to describe the flow of water through aquifer beds. Today the relationships described by Darcy’s law can be used to describe the flow of beer through a filter or filter bed. It is not discussed in any depth in the present article but details may be found in the references. It covers features engineers need to build the correct and most efficient lautering systems. See lautering. Filter bed: A layer of material laid down or allowed to form for the purposes of percolating liquid through to effect a clarification or removal of unwanted solids or concentration of a particular fraction of matter. The mashed (spent) grain forms the filtration bed. Wort is recovered from the spent grain in an act known as sparging. See sparging, spent grain and wort. Filtration/Filterability: The act or process of filtering; a mechanical separation of a liquid from any undissolved particles suspended within in it. Filterability is regulated by the permeability of the filter bed. Permeability is defined by the parameters described in Darcy’s law. See filter bed and Darcy’s law. First runnings or first worts: Referring to the liquid that is formed during the initial period of separation or draining off of sweet wort from the spent grains. It is more concentrated than the subsequent (secondary and final) runnings since the latter is diluted with the sparging liquor. See liquor and sparging. Foundation liquor: Foundation liquor (water) is a term used in relation to the operation of a lauter tun. It refers to a hot water addition to the lauter vessel in the first stage of operation before the addition of the mash. Foundation liquor is allowed to flood the space between the true and false bottom of the vessel and to about 1–2 cm above the false bottom. This serves to both drive out air from this section of the lauter tun while also providing the “cushion” upon which the mash is “floated” during charging (filling). See liquor and lauter tun. Grist: The mixture of solid raw materials, usually malts and possibly various other solid sources of extract which have been milled or prepared ready for mashing and subsequent lautering. Grist composition describes the nature and proportions of the solid materials that make up the charge, which is introduced into the mill or may refer to the milled product. See lautering. Lautering: The general term for the method of separating sweet wort from spent grain. In some systems both mashing and lautering take place in/from the same vessel (mash tun) whereas in others the mashing is done in a separate vessel and carefully transferred to a separate vessel the lauter tun or mash filter. The term lauter is derived from the German word ablautern meaning to clarify or purify. See lauter tun, mash filter and mash tun. Lauter tun: The separate vessel used in brewing for separating sweet wort from the solids in the mash (spent grains). In essence it’s a large sieve-like device with a slotted/perforated floor also called the false bottom. The mash forms a bed on top of the floor and water is trickled over the bed in the process known as sparging. They were originally associated primarily with decoction mashing as used for lager production by mainland European brewers. In German the term Läuterbottich will be seen for lauter tun. See mash filter, mash tun, sparging, and wort. Liquor: A term used for brewing water. Mash filter: A mash filter is an alternative name for a mash press. See mash press. Mash filter is the term used in this article. Mash press: As an alternative to lauter tuns mash presses are devices used at the end of the mashing phase of wort production for the separation of sweet wort from spent grains. See lauter tun and mash tun. Mash tun: Mash tuns are typically associated with traditional UK-style ale production. They are vessels which serve the dual functions of mash conversion and separation of sweet wort from spent grains. See lauter tun and mash press/mass filter. Oberteig (or Teig): An important term that appears in the literature often without much explanation. It refers to the accumulation of fine particles on top of the grain bed in the lauter tun and the formation of a relatively impervious layer (the Oberteig, translated as “upper paste”) which can impede filtration. Accumulation is made worse by recycling of worts and oxidation of this layer can further increase the detrimental effect on filtration. See Filtration/Filterability, lauter tun and wort. Run-off: The term in lautering used to describe the extraction or release, via washing or sparging, of the wort from the mash separation vessel. See lauter tun, mash tun, mash filter, sparge/sparging and wort. Sparging: The spraying of fresh hot liquor (brewing water) onto the mash filtration bed to rinse (or sparge) out the residual sugars and nutrients to produce the final wort. See filter bed, filtration/filterability and liquor. Spent grains: Also known as draff constitute the solid residue that remains after wort has been separated from the mash. The composition varies with the type of grist used but contain the remnants of the husks and other plant materials minus the soluble components that have been extracted into the liquid wort. The removal, treatment and disposal of spent grains is a complex topic in itself and is not discussed in depth in the present article. See grist and wort. See grist and wort. Sweet water, or residual wort runnings: The liquid collected after sparging and at a point where the extract content has fallen to a level below which it is considered desirable to send on to the kettle. It may be used in various ways, for example, in the next mashing-in cycle, as foundation water or sparge liquor. In German the term is glattwasser. See liquor and sparging. Underletting: A process used in mashing in which hot liquor is allowed to enter the mash via the false bottom of a mash tun. The hot liquor is added slowly such that it lifts or “floats” the bed of grains off the false bottom such that they may be mixed and diluted. Vorlauf: German term for the recirculation of the first runnings or first worts. After mashing or mash transfer particulate grain material (including husk fragments) may remain in suspension under the vessel’s false bottom. The liquid with these suspended solids is known as the first wort which is usually turbid. These particles harbor lipids and phenolic compounds which when boiled in the wort kettle (or copper) lead to harsh and unpleasant flavors in the beer. Vorlaufing is a process that collects these materials and recirculates them back onto the surface of the grain bed to prevent them entering the wort stream. The process is not discussed in depth here. See copper, first runnings and wort. Wort: Pronounced “wert”. The extracted sugars and soluble matter (including nutrients – amino acids, minerals etc.) obtained from the grist (grain formulation) during mashing and which will ultimately be fermented by yeast. A clear and highly efficiently produced wort of appropriate gravity is the goal of mashing and lautering. Sometimes called sweet wort prior to boiling with the hops. Its composition differs with respect to the intended beer style under consideration. See grist, mashing, lautering.
Posted on: Sat, 10 Jan 2015 22:50:57 +0000
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