Step infusion is a beer mashing method where differing temperatures and quantities of water are infused in the mash tun from the hot liquor tank at specific intervals or steps in the mash process to control sugar conversion and extraction.
Tag: mashing
Recirculation is the process of pulling the wort from the base of the mash tun or lauter tun and recirculating it back on to the top of the grain bed. Recirculation typically occurs after the end of the mashing process. As the hot wort is recirculated through the grain bed of the mash, the grains act as a particle filter clearing the wort. As the wort is recirculating, it becomes cleaner and less turbid until finally it is clear and ready to be passed to the boiling vessel.
A pump is typically used to recirculate the wort at a steady and controlled pace. In the case where a home brewer does not have a pump available, the wort may be drawn into a container and slowly poured back on top of the grain bed. The process can be repeated until the wort has become clear. Additionally, rice hulls may be added to a mash as a means of boosting the filtration capability of the grain bed.
A wide selection of home brewing recirculation pumps can be found here:
Wort recirculating in the mash tun, prior to sparging and transferring the wort to the boil kettle.
Wort Recirculating in the Mash Tun
Sparging is a brewing process that involves passing heated water through the grain bed of a mash to extract sugars from the crushed grains and adjuncts. Sparging is typically conducted at approximately 167° F to 170° F; if the temperature exceeds 170° F, the brewer risks extracting excessive amounts of tannins from the grains. If the temperature is too low, then the sparge will be ineffective at liquefying the remaining converted sugars from the grains. While the sparge water passes from the hot liquor tank to the mash tun, or lauter tun, via a sparge arm, the extracted sugars and water are being drained from the base of the vessel and relocated to the boil kettle in preparation for to upcoming boil.
This mash is being sparged at 168° F, while the beer is being transferred from the false bottom at the base of the mash tun over to the boil kettle.
Sparging in the mash tun, while wort is transferred to the boil kettle.
Saccharification in very basic terms is the conversion of starches to sugars. When it comes to all grain brewing, saccharification is a critical conversion process that occurs during mashing. As the mash tun’s temperature is increased to a range of 120° F to 158° F, the diastatic enzymes of the malted grains begin to activate and break the starches of the grains and adjuncts into sugars. The alpha amylase enzymes break apart complex starches into sugars that the beta amylase enzymes break apart even further into easy-to-ferment maltose sugar.
Precision is critical when it comes to the temperature of a mash and 10 degrees makes a massive difference. Beta amylase is more temperature dependent than alpha amylase, and when the temperature in the mash begins to rise above 158° F, the beta amylase is no longer capable of breaking apart the more complex sugar chains into maltose. So if your target mash temp is 152° F and you instead conduct your mash at 162° F, you will be left with a massive amount of unfermentable sugars in your finished beer, and it will have a fuller body and overly sweet finish.
Beta amylase thrives in a temperature range of 140° F to 150° F, so if your target mash temp was 152° F and you conducted your mash at 142° F, you would end up with a beer with a very thin body and dry finish due to a deficiency of unfermentable sugars. This is the reason why the typical mash saccharification rest temperature is in a range of 152° F to 154° F; it provides a good temperature compromise for both alpha amylase and beta amylase to carry out their required starch and sugar conversion processes.
Mashing is the process of mixing and infusing crushed malts, unmalted grains, and adjuncts with hot water from the hot liquor tank. As the grains and adjuncts mix with the hot water at specific temperatures, enzymes from the malt activate and convert the starches into sugars. At the same time that the starches are being converted to sugars, color is also being extracted from the grains, which is the primary determining factor of the beer’s final color. The mashing process takes place in a brewing vessel called a mash tun.
Below is a photo of crushed grain being stirred in the mash tun during the mashing process.
Grains being mashed during the mashing process.
The mash is water-saturated crushed malts, unmalted grains, and adjuncts that are present in the mash tun when the mashing occurs. During the mashing process, the starches will be broken down into sugars so they can be fermented by the yeast and converted into alcohol.
The mash for an American Wheat Hefeweizen towards the end of the mashing.
A mash tun is a brewing tank used for converting and extracting sugars from grains and certain types of adjuncts. The crushed grains are loaded into the mash tun and then mixed with temperature controlled hot water. The hot water causes an enzyme reaction in the grains that converts their starches to sugars. The sugars are then rinsed from the grains with hot water that helps liquefy the sugars so that they can be more easily extracted from the grains. Many mash tuns are fitted with a raised perforated false bottom that permits the sugars to be extracted from the grains without requiring the grain husks to be transferred to the next stage of the brewing process.
The photo below displays a mash tun in the WestCoastBrewing.com home brewing sculpture/beer rack. The mash tun is in the center with the hot liquor tank to the right and the boil kettle to the left.
Photo of a home brewing Mash Tun.
20 gallon home brewing mash tun with false bottom
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