Grain Mashed Beers

January 18, 2020

For Level 2 artisans

Copied with permission from and



Grains contains starch, a complex polysaccharide, which simple unicelled creatures like yeast cannot digest. The next couple of chapters will talk about two different ways to convert this starch into fermentable sugars.


Malted grains are sprouted and roasted so that they naturally create enzymes needed to breakdown starch into fermentable sugars. We will discuss malt making process in detail in the subsequent chapters.


Unlike the simpleton malt extract recipe, grain based mashing requires some investment (not too much) into equipment. Below are the few additional steps in the wort making process that one needs to perform:


  1. Firstly, one need to make a grain bill (which is a brewer’s term for the type and quantity of various grains to be used). Unlike extracts, grains will have husk and other unextractable portion, which needs to be accounted for. Hence, about 250-300gm of grains per liter of grains is needed to get the same result. Following steps will help us customize the grain bill:


  1. Do experiment with a bit of malted wheat, crystal, biscuit and dark malts to get a better brew. Adding a bit of oats and some local grains will also be a good choice.


  1. Adding adjuncts or unmalted grains is something that can also be experimented with. Torrified wheat, Oak chips, rice flakes and peated barley would be the most commonly used adjuncts in the industry.


  1. For light bodied beers (crisp, low maltiness) or high gravity (higher alcohol content), one can even use some sugar along with the grains.


  1. Please stay away from legumes (including chickpeas) and grains with high fat content. Any source of starch is welcome though.


  1. The malt extract was used in syrup or powder form and was readily poured from the pouch. However, the grains needs to be malted, and then milled before they can be used in the mash. A porridge/ dalia like consistency is what is needed where a single grain is broken into two or three pieces. If one powders them into flour, then the gluten will bind together making extraction, filtering and lautering (separating the spent grains from the wort after the mashing is complete) impossible. If the grain is not broken, then the enzymes will not reach out to starch efficiently and generate good yields of maltose (wort sg).


Mash-tun (insulated mashing vessel)


  1. Since grains do not dissolve readily, one would need a mechanism to ensure that the heat from the bottom does not char the grains (kettle caramalization) and one could maintain the uniform temperature across the wort. A muslin bag and a cooking thermometer is ideal to begin with. However, serious brewers quickly switch to a mashtun (an insulated water container where calculated quantities of boiling water is introduced to achieve finer temperature controls). Industrial brewers prefer a water-bath or indirect heating setup using dry steam.


  1. Ever wondered, why it is called beer brewing? The bulk of the flavors come from how the heat is applied to the wort. The same set of ingredients can yield different flavors by just altering the temperature profile. Be careful about the mashing temperature profile. Enzymes need an ideal temperature to act as a catalyst converting starch to maltose. If the temperature is too low, it will take forever and at too high a temperature, the proteins will be denatured. Keeping the mashing vessel in an insulated container or a water bath is recommended to maintain the uniform temperature profile. A lautertun made from an insulated water cooler is good to maintain the temperatures.


Holding these temperatures for a period of time are called . Below is the major types of rests given to allow the naturally present enzymes in the malt to act on the grain:


  1. Acid Rest: (35o for 5 minutes). This is the most temperature sensitive process. It is given to allow Phytase enzyme to break-down phytin and release phytic acid. It lowers the mash pH.


  1. Glucan rest: (45oC for 10 minutes) The Beta-Glucaneese enzyme breaks down the glucans and lower the wort viscosity. The resulting beer will have much lower haze as well. When making wheat or rye beers, holding the wort temperature at 45o for 15 minutes really speeds up the lautering process.


  1. Protein rest: (44o-59oC for 15-30min). This is to break down proteins. Long chain proteins causes haze instability and needs to be modified. Proteinase enzyme makes medium chain proteins which adds to the body of the beer. While, peptidase enzyme reduces the medium chain proteins into smaller peptic acids, which is not desirable. These enzymes are naturally created during the malting process.




  1. *Beta Amylase* (60o for 30-45 minutes): In this step, the starch is broken down into maltose (fermentable sugar) This is the most critical step in the entire mashing cycle and determines the brewing efficiency, wort gravity and most of the beer’s characteristic. A long beta rest will lead to a high gravity dry beer with low maltiness.


  1. Alpha-amylase (70o for 15-30 minutes): This is the second amylase enzyme. Its primary job is to break starch molecule into longer chain soluble sugars. The resulting wort is sweet but it is not readily fermentable. As a result one makes full bodied sweet beers.


  1. Mash Out (75o for 5): This step is required only for full bodied beer. The goal is to denature the amylase enzyme so that the wort fermentability does not increase during the wort separation and lautering (removal of grain process).


It is not needed to give all the six temperature rests. Based on the grain bill and final recipe characteristics, the mashing profile can be altered. Alpha amylase enzymes are more active at 70oC and lead to more long chain complex sugars (more body). While beta/ gluco enzymes are more active at 60o giving rise to more fermentable sugars (lesser body). Altering the ratios between these two stages can lead to changes in the brew profile. Some recipes call for a mashing which is faster and simpler to monitor. Essentially, it is a simplification process, where we maintain only one single temperature instead of varied ranges.


  1. This heating for elongated period introduces additional problems of evaporation of water. Home brewers should typically use about 10% extra water to compensate for evaporation loss and water that gets absorbed by residual grain. The boiling off rate is dependent on the equipment used and the size of the batch. Luckily, a lot of online calculators are available to do this job of tweaking the recipe for us.


  1. At the end of the cycle, the grains would have absorbed a lot of water and sugars. Hence sparging/ washing the grains with some warm water is recommended to improve the extraction efficiency (taking sweet sticky maltose out of grains). Improper sparging is the primary reason for some home-brewers not being able to hit the target specific gravity.


  1. Wort Oxygenation: During the mash-out (last rest) and boiling, much of the dissolved oxygen in the wort is expelled. To create a healthy yeast culture in the fermentation, we need a 4-6ppm of dissolved oxygen.


  1. Tincture iodine (easily available in chemist shop or first aid kits) turn purple when added to starch. This is the easiest test that most brewers use to check if the mashing process is complete. For this we need a few teaspoons of wort and a drop of iodine. Residual starch in wort not only causes starch haze but also lower extraction efficiency. Poor quality starch and inadequate amylase rests are the primary reasons.


  1. Most recipe books will have instructions to introduce hops in the wort with time. Please note that this time is the countdown time (i.e. time to flame off). Typically, aromatic hops are added in the last 10-15 minutes of boil, while bittering hops in the last 45-60 minutes. Some recipe call for flavored hops, which are added in the last 15-20 mins from flame off.


  1. Most wheat based recipes will also call for infusion of coriander seeds and orange peels in the boil. Similarly, some Christmas styles will have roasted pumpkin and spices infused. For most practical purposes, treat them as hops. If the aromatic component is high (like cloves) then add them late in the boil. If the resinous component of the spice is high (like cinnamon), then introduce them early.


  1. Aztecs name for chocolate was xocoatl (bitter water). It was used to make beers bitter, long before hoppy beers became prevalent. From Choco powder to fruit puree, don’t be shy to dream or experiment with the magical combination of ingredients. Some puritans will quote the German beer laws which permits only Barley, hops, yeast and water to be added. However, craft beers is all about fusion and experiments. Milkshake IPA and milk stouts, which are gaining popularity these days, have added lactose (an un-fermentable sugar) to get a balanced sweet palate.


  1. Sometimes, I make a single large batch in my mashtun but then I divide it into a dozen fermenters and test various dry hopping combinations. Commercial breweries also have a similar pilot batch concept where they make about 100Liters batch of different flavors for market research.


  1. Grains and boiling wort need space. Hence, it is recommended to take a larger brew kettle than the fermenter. In addition, grains tend to clog up the filtration equipment. Test run with a smaller batch for potential problems during lautering before making a full scale batch.


  1. If wheat, sorghum, oaks, rice flakes and other husk free grains are used in high concentrations, then adding some rice hulls to the boil is recommended. These hulls will form a natural filtration bed, allowing the separation of wort from the spent grains without choking the exits and pipes.


  1. Please don’t forget to sanitize the equipment and pasteurize the wort. Carelessness and improper sanitation is the fastest way to ruin a batch.


  1. Once you start designing your own recipes, it might be a good idea to refer to a BIAB calculator (Brew In A Bag) for the SRM (color) and bitterness (IBU). There are tons of brewing resources available online.


  1. Please record the recipe and observations in a logbook. There is nothing more frustrating than stumbling upon a hit recipe and then failing to recreate it.


Regular all grain mashing home-brewers should invest into a thermostat or an IoT app powered electric/ flame controller. This will allow us to let electronics manage the brew and even program the recipe to get consistent results.


Apart from the above changes, the two styles of beer (extract and grain mashing) making are essentially the same. All grains beer brewing gives the brewer much more flexibility and freedom to design their craft beers. This book focuses to make you a reasonable hobbyist. In the next page, we will be using some of the above knowledge to make a wheat beer.

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