BSU #2 - How Beer is Made: From Grain to Malty Soup
This week we tackle the topic of how to go from a grain growing on some grass, to a sweet fermentable liquid. It's harder than you'd think, and was probably discovered by accident.
There are basically three steps that'll get you from grass to yeast food:
In the previous episode of Brew State University (on which ingredients go into beer), we talked about malted barley. Since barley is the most popular grain for making beer by far, I'll stick to talking about barley, but note that wheat and rye can also be used (for example).
Raw grains are awful, and are unfit for human consumption[1]. To be able to consume the grain in a pleasant way, we need to turn the complex starches into short chain, simple sugars. To do this, the raw (clean) grain is dunked in and out of fresh water, for up to two days. The grain is periodically soaked, and then drained for approximately eight hours each at a time[2].
During this time, the grain absorbs water. This water triggers hormones that are responsible for getting the seed to start growing into a plant. Tiny little roots, called "chits", begin to appear, and the process of steeping the grain is stopped.
The grain is now transferred into a "germination room" which has a pleasant temperature of between 16° and 19°. We're only lulling it into a false sense of security though. The steeped grain is laid out on the ground at a depth of two to ten inches, and is turned[3] frequently for four to six days to stop the chits from matting together, and to remove excess moisture, heat and carbon dioxide from the grain closer to the bottom.
During both processes, the grain has been "germinating"[4]; a process which was started during steeping, but continued in the germination room[5]. To germinate, the seed needs energy. Luckily, it's been safely storing all of the energy it will ever need as starch. Enzymes in the plant begin to break the starch down for ready for our little seed to grow up. However, before it can consume much of its hard fought bounty, we send the seed for drying, killing its hopes and dreams.
The germinated barley is now sent to a kiln for about two to four hours, at a temperature of between 80° and 90°. The extreme heat has finally defeated the once innocent little grain, and the enzymes halt the process of breaking down the starches. The dried grain can now be stored for months without spoiling. Note that when the grain is introduced to water (in the mashing phase) the enzymatic processes will begin again.
Some modifications to this process can yield specialty malts. For example, if the malt is stewed until the starch completely break down, and the liquidised sugar is then roasted, we produce caramel or crystal malts. Or, if the drying temperatures are higher, the resulting dark, roasted malt will yield new flavours. However, these malts have become denatured[6], meaning no further enzymatic processes can occur in the mashing process, and the malt cannot be used as the base (main) malt[7].
There are basically three steps that'll get you from grass to yeast food:
- Malting.
- Mashing.
- Boiling.
Malting
 |
| Figure 1: A traditional malting floor. |
In the previous episode of Brew State University (on which ingredients go into beer), we talked about malted barley. Since barley is the most popular grain for making beer by far, I'll stick to talking about barley, but note that wheat and rye can also be used (for example).
Raw grains are awful, and are unfit for human consumption[1]. To be able to consume the grain in a pleasant way, we need to turn the complex starches into short chain, simple sugars. To do this, the raw (clean) grain is dunked in and out of fresh water, for up to two days. The grain is periodically soaked, and then drained for approximately eight hours each at a time[2].
During this time, the grain absorbs water. This water triggers hormones that are responsible for getting the seed to start growing into a plant. Tiny little roots, called "chits", begin to appear, and the process of steeping the grain is stopped.
The grain is now transferred into a "germination room" which has a pleasant temperature of between 16° and 19°. We're only lulling it into a false sense of security though. The steeped grain is laid out on the ground at a depth of two to ten inches, and is turned[3] frequently for four to six days to stop the chits from matting together, and to remove excess moisture, heat and carbon dioxide from the grain closer to the bottom.
During both processes, the grain has been "germinating"[4]; a process which was started during steeping, but continued in the germination room[5]. To germinate, the seed needs energy. Luckily, it's been safely storing all of the energy it will ever need as starch. Enzymes in the plant begin to break the starch down for ready for our little seed to grow up. However, before it can consume much of its hard fought bounty, we send the seed for drying, killing its hopes and dreams.
The germinated barley is now sent to a kiln for about two to four hours, at a temperature of between 80° and 90°. The extreme heat has finally defeated the once innocent little grain, and the enzymes halt the process of breaking down the starches. The dried grain can now be stored for months without spoiling. Note that when the grain is introduced to water (in the mashing phase) the enzymatic processes will begin again.
Some modifications to this process can yield specialty malts. For example, if the malt is stewed until the starch completely break down, and the liquidised sugar is then roasted, we produce caramel or crystal malts. Or, if the drying temperatures are higher, the resulting dark, roasted malt will yield new flavours. However, these malts have become denatured[6], meaning no further enzymatic processes can occur in the mashing process, and the malt cannot be used as the base (main) malt[7].
Mashing
 |
| Figure 2: The mash tun at Jennings Brewery. |
Mashing is the process by which all of the grains[8] are added to water in a large vessel called a "mash tun", and heated. The boiling process re-triggers the enzymes in the malted grain into breaking down the final starches, except this time, the sugar water is kept, and all of the leftover grain bits are removed. At the end the sugars will have (nearly) completely dissolved into the water, leaving a sweet, and fermentable liquid called the "wort"[9]. The wort is a soup made up of water and sugars, but also proteins, carbohydrates and other organic compounds. It is this soup that will define the beer's malt character, body, sweetness and mouthfeel.
There is more than one way to mash a tun[10], but most breweries use the "infusion" method (temperatures vary, so I'll give temperatures for a standard pale ale recipe for context). Into the mash tun, the grain is added to water (already at approximately 75°). However, adding the grain will reduce the temperature of the water, and so the water is then brought up to a rest temperature (approximately 65°), and left to sit at this temperature for approximately an hour, being periodically stirred. At the end of the hour, the temperature is again raised (to 77°) to end the enzymatic processes.
So, the standard method requires taking the mash from a starting temperature to a single rest temperature. If you instead rest at different temperatures, for certain amounts of time (say going from 50° to 60° to 70°, and resting on each for 20 minutes), you target certain enzymes in the grain, and hence produce certain proteins. This is called "step mashing", and is required for wheat beers.
Boiling
Unsurprisingly, this is where the wort is properly boiled. This is also the time when hops are usually added. Remember that the longer a hop is boiled, the more of the bitter oils that will be released, producing a more bitter flavour. Some hops are added from the start, and some won't be added until halfway through, near the end, or even after the boil has completed.
This is also the time that other adjuncts can be added. Honey for example could be added during the boil to give additional flavours and sugars (and hence alcohol in the final product).
This is also the time that other adjuncts can be added. Honey for example could be added during the boil to give additional flavours and sugars (and hence alcohol in the final product).
Boiling usually goes for about an hour, and the wort is kept at a rolling boil. The boil is important because it also removes some of the unwanted proteins that cause off-flavours and chill haze[11], and it is the hops which act to remove them.
Finally, the wort is filtered[13], and then quickly chilled down, usually by running it through copper pipes in cold water, or by placing copper tubes filled with running cold water straight into the wort[14]. It is also an option to further cool the wort (down to approximately 3°) to make the chill haze proteins form and clump together, so that they can then be filtered out at this point, producing an especially clear beer. This is known as chill filtering or using a cold break.
Conclusions
Okay, we now know what goes into a pretty standard beer, and how that is brought to a non-alcoholic, bitter-sweet wort. In the next instalment of this series, we'll talk about how we get a nice, bubbly, alcoholic drink, which makes it possible for men to be able to talk to women, and for women to be able to tolerate us.
Sources
a) https://beerandbrewing.com/dictionary/kJavT7eNYH/
b) https://homebrewanswers.com/document/different-types-of-mash/
b) https://homebrewanswers.com/document/different-types-of-mash/
c) https://www.stonebrewing.com/blog/miscellany/2011/chill-hazethe-more-you-know
[2] If I was the grain, I'd give up state secrets on the first day.
[3] Traditionally this was done with a shovel, but now it's a largely mechanised process. I assume means that it's done by a robot with a shovel.
[4] Which is unsurprising as it was in a germination room. However, room names can be misleading, for example, you shouldn't play sports in a ballroom, and you'll be judged for keeping corpses in a living room.
[5] Recall, germination is the process by a seed turns into a plant. Basically seed-puberty.
[6] We broke them at a chemical level, meaning they can't do their thing anymore.
[7] But it does add a lovely flavour to dark beer.
[8] This is everything on the "mash bill" that makes up your grain recipe (minus non-grain adjuncts). Note that either at this point, or up to when the beer will be mashed, the grains are crushed, both physically and emotionally, to make them easier to use.
[9] Even with a terrible name like wort, beer's gone on to do okay for itself.
[10] I might patent this expression.
[11] But haze is such a good thing, right?? Well, no. This is caused by flavourless proteins which only clump together at low temperatures. Since it adds no flavour, Coors is looking into incorporating it into their beers[12].
[12] This is not true.
[13] One interesting way the wort can be filtered is to run it through two inches of loose hop flowers in a strainer.
[14] Copper is used as it is almost completely inert, much like Tori Spelling's acting range.
Figures
1) https://www.weyermann.de/images/news/Startbild_HD_Heirloom%20malt_2011.jpg
2) https://media-cdn.tripadvisor.com/media/photo-s/06/74/23/8f/mash-tun.jpg
Footnotes
[1] Technically you could eat it, but you could also eat a balloon, or worse yet, drink Miller Genuine Draft.[2] If I was the grain, I'd give up state secrets on the first day.
[3] Traditionally this was done with a shovel, but now it's a largely mechanised process. I assume means that it's done by a robot with a shovel.
[4] Which is unsurprising as it was in a germination room. However, room names can be misleading, for example, you shouldn't play sports in a ballroom, and you'll be judged for keeping corpses in a living room.
[5] Recall, germination is the process by a seed turns into a plant. Basically seed-puberty.
[6] We broke them at a chemical level, meaning they can't do their thing anymore.
[7] But it does add a lovely flavour to dark beer.
[8] This is everything on the "mash bill" that makes up your grain recipe (minus non-grain adjuncts). Note that either at this point, or up to when the beer will be mashed, the grains are crushed, both physically and emotionally, to make them easier to use.
[9] Even with a terrible name like wort, beer's gone on to do okay for itself.
[10] I might patent this expression.
[11] But haze is such a good thing, right?? Well, no. This is caused by flavourless proteins which only clump together at low temperatures. Since it adds no flavour, Coors is looking into incorporating it into their beers[12].
[12] This is not true.
[13] One interesting way the wort can be filtered is to run it through two inches of loose hop flowers in a strainer.
[14] Copper is used as it is almost completely inert, much like Tori Spelling's acting range.
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