Malt has been called the heart of beer. It does the most to influence what style a beer will become. At the same time it takes very little variation of moisture or temperature to change malt into something different – whether in the malting process or the brewer’s mash. For instance, in the mash, a one or two degree change will vary the body of the final product. Even though malt is typically barley, there are many different varieties of barley. Maris Otter is one such variety. Others include: Golden Promise, Chevallier, Harrington, Thoroughbred, and Expedition, et al. When sold for homebrewing it is simply malted barley. Other non-barley malts are made from rye, corn, rice, wheat, spelt, etc.


Among these varieties there are two kinds of barley: 2 row and 6 row. The physical difference is when looking down the top of the barley on the plant, the 2 row seeds are opposite each other creating 2 rows. Again, looking down the top of the plant, the 6 row looks more like a star with 6 points. Here are some basic brewing differences in 2 vs 6 row grain.


6 row:

• Smaller grains, more husk material, could cause haze and astringency.

• Produces slightly less fermentable sugars per pound.

• Higher diastatic power – will take longer to denature. Typically used in beers with large percentage of adjuncts (non-enzymatic starches.)

• Higher protein - could cause more haze but more mouth feel, less starch, lower extract.

• Potentially, a more fermentable wort. Produces a grainer flavor.


2 row:

• Larger grains, more consistent size for milling.

• Slightly less protein - potential for less haze.

• Produces a fuller maltier flavor

To sum up: 2 row is the most common barley used in homebrewing. 6 row is used when a high diastatic power is needed to convert more starches to sugars, like when using rice or corn in the mash.


Malt is the result of a non-digestible green seed that begins to germinate inside the husk creating some sugars and more digestible starches. It is then stopped before the seed sprouts. These converted starches are made accessible to the alpha amylase enzymes already existing in the seed. After it germinates, the seed creates the beta amylase enzymes. This whole process is called “modification”.


For the homebrewer, we want to focus more on the types of malt that can be made from barley. In general, malt can be split into the following types: pale, crystal/caramel, specialty, and roasted. Each type is created from changing the variables of temperature, moisture, and time. After modification, almost all types of malt are kilned to give it flavor and color. Pilsner (a pale malt) is the lightest of the malts at a Lovibond of 1-2. Other malts are then roasted much darker with black patent malt being at 500+.


Crystal and caramel malts have become synonymous with each other. They are unique in that they are the most acidic of the malts. The use of crystal malts can assist in lowering the pH of the mash when it is out of range (5.2-5.4). It is potent malt in that is adds a lot of caramel flavors and body, or fuller mouthfeel, to the final product. Light and dark crystal malts are the British versions. U.S. versions range from 10 to 150 Lovibond with the darker versions giving raisin and plum notes.


Specialty malts include Victory, honey, amber, melanoidin, aromatic, acidulated, Special B, smoked etc. Most of these malts need to be mashed. They are all unique in their own ways. Victory tends to give a fresh baked bread aroma and flavor. Acidulated malt is used to decrease the pH in the mash rather than using salts or acids. It is a purist’s approach. Honey malt adds some honey notes. There are two kinds of smoked malt: peat and beechwood. Peat smoked malt is very potent and should be used sparingly. Beechwood smoked malt is much milder and can be up to 100% of the grist. Of course, the best way to learn about all the different grains is to use them or at least taste them.


Roasted malts include chocolate, pale chocolate, Carafa, black patent, and even a wheat version. Roasted barley is not a malt. It is simply a roasted seed offering nutty and coffee-like notes in the classic Dry Irish Stout.    It should be mashed because there is some starch in the seeds. Carafa is a huskless malt which offers less astringency than other roasted malts. Pale chocolate is a black malt that cause less of a color change than chocolate malt. Finally, black patent is a potent color and flavor changer. A mere 2oz can add color to paler beers. Black patent has been roasted so long and hot that it is considered to be sanitized. It can actually be added directly to the fermenter if so desired. This would have the same results a cold brewed coffee – all the flavor with less bitterness.


The diastatic power (DP) of malt is very important. DP is the amount of enzymes in the malt able to convert its starches to sugars during the mash. Pale malts have the most DP and can even convert the starches in other non-DP malts or adjuncts.  The longer and hotter the malt is kilned the more the enzymes are denatured. Crystal and roasted malts have no DP. They have had their starches converted to sugars or been charred so they can be steeped or added to the end of the mash. For instance, crystal malts are made by keeping the grain moist and brought to a temp of 145-155 F for conversion. Then they are dried with hot air and kilned to the correct color between 10 and 150Lovibond. Likewise, the roasted malts have nothing left to convert and simply contribute color and flavor. Specialty malts have varied DP levels and need the enzymes from pale malt to fully convert their starches to sugars.


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All malt should be cracked or milled to make the starches and sugars inside accessible to the enzymes and brewing water. The hull is like our skin, it is designed to keep unwanted things out. Grain naturally does not want to be soaked in hot water. It wants to create another plant. So cracking the hull is necessary to get to the good stuff. The enzymes actually get washed out of the malt and into the wort. This allows them to contact more substrate (starches). If the grain is not cracked, the enzymes would only come in contact with outside of the kernel and mash efficiency would be low.


Many all grain brewers rely on their homebrew store to mill their grain. That is a fine choice, but the cracked grain needs to be used in about two weeks. Any longer and it will start getting stale or worse, moldy. Sometimes a homebrewer might open up the grain bag and for whatever reason find that it is not cracked. Attempting to crack 10 pounds of grain with a hammer or rolling pin is an arduous task. Another issue is that every brewer’s mash equipment is a little different. A particular grain crack might be fine for some, but may cause a stuck sparge for others. These problems can be solved by buying your own two roller barley mill. Sure they cost between $150 and $250, but it is one more step to eliminating potential problems for brew day. There is a cheaper mill called a corona mill, but it gives inconsistent results and still can cost upwards of $100. The advantages of a dual roller mill are: bulk grain can be purchased thus saving money, consistent lauter results, never having the horror of uncracked grain, and more involvement and fun with the whole brewing process. The actual crack size is dependent on the mash/lauter tun being used. The general recommended gap size is between 035and .05 inches. The best way to get the gap correct is with a feeler gauge. The goal is to get the malt in small enough pieces to maximize the extract without clogging the lauter process. To achieve this goal, the husks need to stay as intack as possible. I have found that it’s impossible to keep the husks perfect. They end up breaking in half, but I mill at .040” and have no lauter problems.


There is another method of cracking grain called wet milling. It involves adding a small amount of moisture to the grain and then running it through the mill. This is supposed to preserve the husk better than dry milling and cuts down on malt dust. However, a high quality stainless steel mill is needed because the mill gets wet and could rust. Personally, I find that dry milling works very well.


Once the mash is done and you’ve lautered your sweet wort, it is time to dispose of the spent grain. There are recipes that use the spent grains to make breads or cereals, but there is still a lot left over. I used to let it dry (very hard to do) and throw it in the trash. However, now I use it as fertilizer and mulch. It needs to be cooled down before spreading on grass to avoid burning, but using it as temporary mulch around trees and bushes is a good option. Let it cool and spread it around. The only drawback is that, after a day, it smells for a short period of time, but it provides nutrients and ground cover. It does not last as long as wood mulch, but you’ll brew again and make more!