What is Mashing in Beer Brewing?

There are eight steps in beer brewing. These processes include:

Malting 🡆 Milling 🡆 Mashing 🡆 Brewing 🡆 Fermentation 🡆 Maturation 🡆 Filtration 🡆 Packaging

But at this moment, we’re taking a keen interest in mashing.

In beer production, mashing is the process that precedes brewing. It involves mixing crushed malt with water to create a porridge-like mash. During mashing, the natural enzymes in malt break down starch into fermentable sugars and protein.

In this article, we shall discuss the mashing process in beer brewing, its purpose, and its by-products. But first, let’s introduce the ingredients involved in mashing.

Mashing in Beer Brewing: What Ingredients are Involved?

Mashing in Beer Brewing What Ingredients are Involved

Mashing in beer brewing requires two main ingredients:

  • Malt
  • Water


Malt is a grain product that brewers use in beer making. It is the product of malting, which involves steeping, germinating, and kilning.

Before steeping, grains are sorted and cleaned. Grains, in this case, could be barley, corn, rice, or wheat. It’s also possible to malt a mixture of different grains.

Steeping is the first step of malting. It involves soaking grain in water in the presence of oxygen. Under these conditions, germination starts.

Depending on grain type, steeping can take between 24-48 hours. The process is only complete when the grain reaches optimal moisture levels, allowing uniform protein and starch to break down.

From the steeping tanks, the soaked barley is transferred to germination vessels.

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Germination is the second step of malting. Here, the maltster carefully controls the moisture content of barley while machines turn the grain regularly. The air’s temperature, humidity, and carbon dioxide contents are also carefully controlled to create optimal conditions for germination.

During germination, husks unravel, rootlets emerge, and the first leaves sprout. Depending on grain type, germination can take up to five days.

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After a few days in the germination vessels, the sprouting grain (or green malt) is transferred into the kilns.

Kilning is the final step involving drying the green malt with hot air. Under these conditions, germination stops.

In the kiln, temperatures gradually rise from 130-185°F, or even hotter for specialty malts. By manipulating the kiln’s temperature, malt develops various colors and aromas.

From the kiln, malt is stored in silos awaiting milling.

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During milling, malt is ground to form course particles called grist. Milling optimizes enzyme action in the mashing process by increasing the surface area of malt.


Beer is 95% water. Almost all processes in brewing require water, and mashing is no different. During mashing, warm water is mixed with ground malt (grist) to produce the mash.

The warm water activates the malt’s natural enzymes, which convert starches into fermentable sugars. Enzymes are inactive in dry malt, and we raise the water temperature to optimize enzyme action.

After the enzymatic breakdown of starch, the extracted sugars remain dissolved in water. This solution is called wort.

Now that you understand the ingredients, we can discuss mashing in beer making.

Mashing in Beer Brewing

In brewing, mashing involves mixing ground malt with heated water. Mash is a porridge-like mixture that contains grist suspended in water. During mashing, the enzymes within the malt break down starch into soluble and fermentable sugars. The resulting solution from malting is called wort.

In modern brewing, there are two main methods of mashing:

  • Infusion Mashing
  • Decoction Mashing

Infusion mashing involves heating the entire mash from rest temperature to rest temperature. Decoction mashing, on the other hand, involves heating a portion of mash to boiling point, then adding it to the rest of the mash.

In brewing, the mashing process takes place in two phases:

  • In the Mash Tun
  • In the Lauter Tun

Mashing in the Mash Tun

Mashing in the Mash Tun

The mash tun is an essential brewhouse vessel. It’s used in the first mashing phase, where ground malt is constantly mixed with water and subjected to heat.

Traditionally, the mash tun is a cylindrical vessel made of stainless steel, wood, or copper. Many brewmasters prefer stainless steel vessels because of their durability and ease of cleaning. However, wood and copper alternatives could impart flavor to the beer.

In the mash tun, ground malt and warm water are constantly turned while the temperature is raised from 113-172°F. At a suitable temperature, enzymes in the grist convert starch into fermentable sugars. This process is called saccharification.

The success of saccharification relies on four main variables. These factors include time, temperature, pH, and mash thickness. The brewmaster must monitor and manipulate all these elements to attain the desired taste and alcohol content.

The style of beer being brewed will dictate how long the beer has to spend in the mash tun. Light lagers, for example, spend less time in the vessel than stouts and porters.

The pH levels of the mash affect enzyme activity. Enzymes work best when the mash pH is between 5.2-5.6.

After saccharification, the mash is transferred to the lauter tun, where it is purified.

Mashing in the Lauter Tun

Mashing in the Lauter Tun

Lautering is separating the liquid from the spent grist of mash. This liquid is called wort, and it contains dissolved fermentable sugars. The lautering tun is the vessel that facilitates this separation, and it does it with a system of sieves and rotating blades.

In brewing, the lautering process consists of three steps:

  • Mashout
  • Recirculation
  • Sparging


Mashout involves stopping the saccharification process (or the enzymatic conversion of starch into fermentable sugars). First, the brewmaster raises the temperature of the mash to 170 °F. At this temperature, enzyme action stops, and the mash loosens.

While mashout is optional, it is necessary when your mash contains less than 3 pints of water per pound of malt. Mashout is also necessary when your malt has more than 25% oats or rice.


Recirculation involves drawing wort from the bottom of the lautering tun and rerunning it through the vessel.

During the first round of lautering, the grist settles at the bottom, partially clogging the sieves. During the second round, the sediments act as an additional filtration device, holding back the finer particles that went through in the previous round.


Sparging is the continuous addition of water to extract fermentable sugars from the grist. Sparging is a pH and temperature-sensitive process. Set the wrong temperature or generate the wrong pH, and your water will extract tannins from grain husks.

There are two techniques in sparging; batch sparging and fly sparging.

Batch sparging (or English sparging) involves draining the lauter tun completely before adding hot water. The resulting mixture is held at 169°F before draining the lauter tun. In most cases, the brewmaster uses resulting wort to make low-alcohol beer.

Fly sparging (or German sparging) involves continuous water trickling when the wort level is about an inch above the grain bed. The process is slow. And as the wort grows weaker and weaker, the brewmaster stops adding water.

What Happens After Mashing?

What Happens After Mashing

Mashing yields two products:

  • Wort
  • Spent Grain


Wort is the liquid you extract from mashing. It contains dissolved fermentable sugars that will feed yeast in the fermentation process.

Wort is critical to the taste and alcohol content of beer. From the lautering tun, wort proceeds to the brewing kettle. Here, hops are added before the mixture is boiled for up to 2 hours at 176 °F.

Spent Grain

Spent grain is the solid residue that sinks at the bottom of the lautering tun. It consists mainly of ground grains, sprout shells, and insoluble proteins. Spent grain can be repurposed for various purposes.

Common uses of spent grain include:

  • Bread Baking: The solid residue can be used to make spent grain bread (or Treberbrot in German). Almost all bread recipes can accommodate spent grain. For example, spent grain from Pilsner brewing makes a delicious light sandwich loaf.
  • Animal Feed: Chickens love spent grains. Dairy cows are any different. In commercial brewing, spent grains are widely repurposed as cattle feed to improve milk yield.
  • Composting: Spent grain is rich in insoluble protein, which contains nitrogen. Plants need this nitrogen to generate energy.

Pro Tip: Adding carbon-rich brown plant matter can boost your compost’s nitrogen levels. Wood chips, coffee grounds, and dry leaves are viable additives.

Final Thoughts

In beer brewing, mashing is a critical process. It extracts sugars from grain in preparation for fermentation. Mashing also plays a crucial role in determining the taste and alcohol content of beer.

And there you have it, everything you need to know about mashing. What brewing process should we tackle next? Let us know in the comment section below.

What is Mashing in Beer Brewing

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