In brewing and distilling , mashing is the process of combining a mix of ground grains – typically malted barley with supplementary grains such as corn , sorghum , rye , or wheat (known as the " grain bill ") with water and then heating the mixture. Mashing allows the enzymes in the malt (primarily, α-amylase and β-amylase) to break down the starch in the grain into sugars , typically maltose to create a malty liquid called wort .
42-467: Wort ( / ˈ w ɜːr t / ) is the liquid extracted from the mashing process during the brewing of beer or whisky . Wort contains the sugars , the most important being maltose and maltotriose , that will be fermented by the brewing yeast to produce alcohol . Wort also contains crucial amino acids to provide nitrogen to the yeast as well as more complex proteins contributing to beer head retention and flavour. The first step in wort production
84-445: A mash tun . Breweries implementing a decoction process must possess at least two dedicated vessels. Mash tuns have a powerful stirring mechanism, known as a mash rake , to keep the temperature of the mash uniform. They also have an efficient heating method, often based on steam , that will not scorch the malt. This heating method is combined with proper insulation enabling mash to maintain rest temperatures for up to one hour inside
126-429: A balance between breaking down these proteins and limiting FAN production. The amylase rests are responsible for the production of free fermentable and non-fermentable sugar from starch in a mash. Starch is an enormous molecule made up of branching chains of glucose molecules. β-amylase breaks down these chains from the end molecules, forming links of two glucose molecules, i.e. maltose . β-amylase cannot break down
168-493: A delicate step, as the wrong temperature or pH will extract tannins from the chaff (grain husks) as well, resulting in a bitter brew. Typically, 1.5 times more water is used for sparging than was for mashing. Sparging is typically conducted in a lauter tun. English sparging (or batch sparging) drains the wort completely from the mash, after which more water is added, held for a while at 76 °C (169 °F) and then drained again. The second draining can be used in making
210-403: A half hours. This long boil extracts resins, which provides the bittering. Then, the flavouring hops are added, typically 15 minutes from the end of the boil. The finishing hops are added last, toward the end of or after the boil . This extracts the oils, which provide flavour and aroma but evaporate quickly. In general, hops provide the most flavouring when boiled for approximately 15 minutes, and
252-415: A lighter-bodied low-alcohol beer known as small beer , or can be added to the first draining. Some homebrewers use English sparging, except that the second batch of water is only held long enough for the grain bed to settle, after which recirculation and draining occurs. Fly sparging (or German sparging), which is used by commercial breweries and many homebrewers, uses continuous process sparging. When
294-455: A portion of the grains and then returning them to the mash, raising the temperature. The boiling extracts more starches from the grains by breaking down the cell walls. It can be classified into one-, two-, and three-step decoctions, depending on how many times part of the mash is drawn off to be boiled. Decoction is a traditional method and is common in German and Central European breweries. It
336-402: A starch haze in the finished product. In larger quantities, an unpleasantly harsh flavor can develop. Therefore, the mash-out temperature rarely exceeds 78 °C (172.4 °F). If the lauter tun is a separate vessel from the mash tun, the mash is transferred to the lauter tun at this time. If the brewery has a combination mash- lauter tun, the agitator is stopped after mash-out temperature
378-451: A uniform temperature in the mash is not a priority. To prevent a scorching of the grains, the brewer must continuously stir the decoction and apply slow heating. A decoction mash brings out a higher malt profile from the grains and is typically used in Bock or Doppelbock beers. After the enzyme rests, the mash is raised to its mash-out temperature. This frees up about 2% more starch and makes
420-404: Is a flap which can be raised and lowered for pushing the spent grains out of the tun. The brewer, or better yet an automated system, can raise and lower the rake arms depending on the turbidity (cloudiness) of the run-off, and the tightness of the grain bed, as measured by the pressure difference between the top and bottom of the grain bed. There must be a system for introducing sparge water into
462-453: Is complete. Craft breweries often have manways on the side of the mash tun for spent grain removal, which then must be helped along to a large extent by the brewer. Some small breweries use a combination mash/lauter tun, in which the rake system cannot be implemented because the mixing mechanism for mashing is of higher importance. The stirring blades can be used as an ersatz rake, but typically they cannot be moved up and down, and would disturb
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#1732772266472504-541: Is practiced in order to break down cell walls and make starches more available, thus raising the extraction efficiency. Should the brewer let this rest go on too long, it's possible that a large amount of β-glucan will dissolve into the mash, which could lead to a stuck mash on brew day and cause filtration problems later in beer production. Protein degradation via a proteolytic rest plays many roles: production of free-amino nitrogen (FAN) for yeast nutrition, freeing of small proteins from larger proteins for foam stability in
546-427: Is reached and the mash has mixed enough to ensure a uniform temperature. Lautering Lautering ( / ˈ l aʊ t ər ɪ ŋ / ) is the beer brewing process that separates the mash into clear liquid wort and residual grain. Lautering usually consists of three steps: mashout, recirculation, and sparging. Mashout is the term for raising the temperature of the mash to 77 °C (170 °F). This stops
588-420: Is to obtain malt , which is made from dried, sprouted cereal grains, including barley . The malt is run through a mill, cracking the husk and exposing the starch inside. The milled grain is then mashed by mixing it with hot water, and then steeped , a process that enables enzymes to convert the starch in the malt into sugars which dissolve in the water. Sometimes the mash is heated at set intervals to alter
630-430: The enzymatic conversion of starches to fermentable sugars , and makes the mash and wort more fluid. Mashout is considered especially necessary if there is less than 3 liters of water per kilogram of grain (3 pints of water per pound of grain), or if the grain is more than 25% wheat or oats . The mashout step can be done by using external heat, or by adding hot water. Recirculation consists of drawing off wort from
672-416: The lautering process . Mixing of the strike water used for mashing in and milled grist must be done in a way that minimizes clumping and oxygen uptake. This was traditionally done by first adding water to the mash vessel and then introducing the grist from the top of the vessel in a thin stream, but this led to a lot of oxygen absorption and loss of flour dust to the surrounding air. A premasher, which mixes
714-406: The pH of the mash and its thickness. A thicker mash acts as a buffer for the enzymes. Once a step is complete, the enzymes active in that step are denatured by the increasing heat and become permanently inactive. The time spent transitioning between rests is preferably as short as possible; however, if the temperature is raised more than 1 °C per minute, enzymes may be prematurely denatured in
756-614: The Old English verb mæscan, which means "to mix with hot water". Usage of the term to refer to "anything reduced to a soft, pulpy consistency" is recorded as early as the late 16th century. The end product is called a "mash". Most breweries use infusion mashing, in which the mash is heated directly to go from rest temperature to rest temperature. Some infusion mashes achieve temperature changes by adding hot water, and some breweries do single-step infusions, performing only one rest before lautering . Decoction mashing involves boiling
798-399: The bottom of the mash, and adding it to the top. Lauter tuns typically have slotted bottoms to assist in the filtration process. The mash itself functions much as a sand filter to capture mash debris and proteins. This step is monitored by use of a turbidimeter to measure solids in the wort liquid by their opacity . Sparging is trickling water through the grain to extract sugars. This is
840-407: The branch points, although some help is found here through low α-amylase activity and enzymes such as limit dextrinase. The maltose will be the yeast's main food source during fermentation. During this rest, starches also cluster together forming visible bodies in the mash. This clustering eases the lautering process. The α-amylase rest is also known as the saccharification rest . During this rest,
882-425: The enzyme activity. The temperature of the mixture is usually increased to 78 °C (172 °F) for mashout . Lautering is the next step, which means the sugar-extracted grist or solids remaining in the mash are separated from the liquid wort. In homebrewing , the use of grain malt (including milling and mashing) can be skipped by adding malt extract to water to make wort. The mixture is then boiled to sanitize
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#1732772266472924-403: The finished product, and reduction of haze-causing proteins for easier filtration and increased beer clarity. In all-malt beers, the malt already provides enough protein for good head retention, and the brewer needs to ensure the amount of FAN produced can be metabolized by the yeast to avoid off flavors. The haze causing proteins are also more prevalent in all-malt beers, and the brewer must strike
966-473: The grain directly above the outlet. In the past, the run-off tubes flowed through swan-neck valves into a wort collection grant. While visually appealing, this system led to a lot of oxygen uptake. Such a system has mostly been replaced either by a central wort-collection vessel or the arrangement of outlet ports into concentric zones, with each zone having a ring-shaped collection pipe. Brewhouses in plain public view, particularly those in brewpubs , often maintain
1008-519: The grains are heated in one vessel, and decoction mashing, in which a proportion of the grains are boiled and then returned to the mash, raising the temperature. Mashing involves pauses at certain temperatures (notably 45–62–73 °C or 113–144–163 °F) and takes place in a "mash tun" – an insulated brewing vessel with a false bottom. The term "mashing" probably originates from the Old English noun masc , which means "soft mixture", and
1050-640: The grist with mash-in temperature water while it's still in the delivery tube, reduces oxygen uptake and prevents dust from being lost. Mashing in – sometimes called "doughing-in" – is typically done between 35–45 °C (95–113 °F), but for single-step infusion mashes, mashing in must be done between 62–67 °C (144–153 °F) for amylases to break down the grain's starch into sugars. The weight-to-weight ratio of strike water and grain varies from one-half for dark beers in single-step infusions to one-quarter or even one-fifth ratios that are more suitable for light-colored beers and decoction mashing, where much of
1092-419: The lauter tun. Most systems have a ring of spray heads that ensure an even and gentle introduction of the sparge water. The watering system should not beat down on the grain bed and form a channel. Large breweries have self-closing inlets on the bottom of the tun through which the mash is transferred to the lauter tun, and one outlet, also on the bottom of the tun, into which the spent grains fall after lautering
1134-406: The mash include oats , wheat , corn (maize), rye , and rice . Adjunct grains may first need gelatinization and cooling. They are used to create varietal beers such as wheat beer and oatmeal stout , to create grain whisky , or to lighten the body (and cut costs) as in commercial, mass-produced pale lagers . Mashing The two main methods of mashing are infusion mashing, in which
1176-415: The mash is taken out of the mash tun and placed in a cooker, where it is boiled for a period of time. This caramelizes some of the sugars, giving the beer a deeper flavor and color, and frees more starches from the grain, making for a more efficient extraction from the grains. The portion drawn off for decoction is calculated so the next rest temperature is reached by simply putting the boiled portion back into
1218-406: The mash less viscous , allowing the lauter to process faster. Although mash temperature and viscosity are roughly inversely proportional, the ability of brewers and distillers to use this relationship is constrained by the fact that α-Amylase quickly denatures above 78 °C (172.4 °F). Any starches extracted once the mash is brought above this temperature cannot be broken down and will cause
1260-415: The mash tun. Before drawing off for decoction, the mash is allowed to settle a bit, and the thicker part is typically taken out for decoction, as the enzymes have dissolved in the liquid, and the starches to be freed are in the grains, not the liquid. This thick mash is then boiled for around 15 minutes and returned to the mash tun. The mash cooker used in decoction should not scorch the mash, but maintaining
1302-410: The mash water is boiled off. In step infusion and decoction mashing, the mash is heated to different temperatures to allow specific enzymes to work optimally. The table at right shows the optimal temperature ranges for key enzymes and what materials those enzymes break down. There is some contention in the brewing industry as to the optimal temperatures for these enzymes, as it is often very dependent on
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1344-407: The most aroma when not boiled at all. At the end of boiling, the hot wort is quickly cooled (in homebrewing , often using an immersion chiller ) to a temperature favorable to the yeast . Once sufficiently cooled, the wort is transferred to a separate fermentation vessel, oxygenated, and then yeast is added, or "pitched", to begin the fermentation process. The adjunct grains that can be added to
1386-440: The otherwise cloudy mash to run out of the lauter tun as a clear liquid. The false bottom of today's lauter tun is made of wedge wire , which can provide a free-flow surface of up to 12% of the bottom of the tun. The run-off tubes should be evenly distributed across the bottom, with one tube servicing about 1 m (11 sq ft) of area. Typically, these tubes have a wide, shallow cone around them to prevent compaction of
1428-423: The same since its first use, technological advances have led to better designed lauter tuns capable of quicker and more complete extraction of the sugars from the grain. The false bottom in a lauter tun has thin (0.7 to 1.1 mm or 0.028 to 0.043 in) slits to hold back the solids and allow liquids to pass through. The solids, not the false bottom, form a filtration medium and hold back small solids, allowing
1470-438: The swan-neck valves and grant for their visual effect. A good quality lauter tun has rotating rake arms with a central drive unit. Depending on the size of the lauter tun, there can be between two and six rake arms. Cutting blades hang from these arms. The blade is usually wavy and has a plough-like foot. Each blade has its own path around the tun and the whole rake assembly can be raised and lowered. Attached to each of these arms
1512-418: The transition layer near the heating elements. β-glucan is a general term for polysaccharides , such as cellulose , made up of chains of glucose molecules connected by beta glycosidic bonds , as opposed to the alpha glycosidic bonds in starch. They are a major constituent of the cell walls of plants and make up a large part of the bran in grains. A β-glucanase rest done at 40 °C (104 °F)
1554-546: The two rests are often performed at once with the time and temperature of the rest determining the ratio of fermentable to non-fermentable sugars in the wort and, hence, the final sweetness of the fermented drink . A hotter rest results in a fuller-bodied, sweeter beer as α-amylase produces more non-fermentable sugars. 66 °C (151 °F) is a typical rest temperature for a pale ale or German pilsener , while Bohemian pilsener and mild ale are typically rested at 67–68 °C (153–154 °F). In decoction mashing, part of
1596-431: The vessels. A spray ball for clean-in-place (CIP) operation helps with periodic deep cleaning. Sanitation is not a major concern before wort boiling, so a rinse-down is usually all that is necessary between batches. Smaller breweries often use a boil kettle or a lauter tun for mashing. Using a lauter tun limits the breweries to single-step infusion mashing, however, because such a vessel is not completely appropriate for
1638-401: The wort and, in the case of most beer production, to extract the bittering, flavour and aroma from hops . In beer making, the wort is known as "sweet wort" until the hops have been added, after which it is called "hopped or bitter wort". The addition of hops is generally done in three parts at set times. The bittering hops, added first, are boiled in the wort for approximately one hour to one and
1680-425: The wort reaches a desired level (typically about 25 mm or 1 inch) above the grainbed, water is added at the same slow rate that wort is being drained. The wort gradually becomes weaker and weaker, and at a certain point, they stop adding water. This results in greater yields. A lauter tun is the traditional vessel used for separation of the extracted wort . While the basic principle of its operation has remained
1722-419: The α-amylase breaks down the starches from the inside and starts cutting off links of glucose that are one to four glucose molecules in length. The longer glucose chains, sometimes called dextrins or maltodextrins , along with the remaining branched chains give body and fullness to the beer. Because of the closeness in temperatures of peak activity of an α-amylase (63-70 °C) and β-amylase (55-65 °C),
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1764-514: Was used out of necessity before the invention of thermometers allowed for simpler step mashing, but the practice is still in use for many traditional beers because of the unique malty flavor it lends to the end product. Boiling part of the grain results in Maillard reactions , which create melanoidins that create rich, malty flavors. To achieve economies of scale , large breweries often possess at least one dedicated vessel for mashing, called
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