In Neolithic times, it must have been quite a wonder that sweet drinks left alone became alcoholic. Stories abound about servants giving old or sour food and drinks to their masters, only to have the master demand more. That’s a subject for another time, but the fact remains that alcoholic food and drinks have been welcomed for as long as humans have known of them.
Alcoholic beverages are present is almost all civilizations. Sumerians worshiped Ninkasi, their goddess of brewing. The Egyptians buried their pharaohs with beer, and even paid their workers with it. No doubt humans believed that beer was something special. That belief persists into modern times.
Cereal grains, such as wheat, sorghum, oats, and especially barley have been converted into intoxicants since prehistory. Getting from “grass to glass” is expensive in time, effort, and materials. Getting it wrong costs the community the raw materials that could have otherwise been bread, the time and energy spent carrying water from springs and streams, and botanicals that were stored in places that could have been used for other purposes. However, getting it right provides a beverage that has safely nourished the community, been considered medicinal, was elevated to the spiritual, and has brought peoples together in celebration for millennia.
We can understand why the beverages were important, but what about their creation? A common understanding is that the origin of fermentation was a happy accident. As the story goes, grains were prepared as a meal. Some of these grains went uneaten and were left out. Being wet, the natural yeasts and bacteria in the air fermented the natural sugars. The result was a porridge that was nutritious and had somewhat pleasing side effects.
We also know that fallen fruit will naturally ferment both on the vine and on the ground. We can observe squirrels getting drunk after eating this fruit, so we must have known early on that alcoholic food and drink can alter behavior, even if we didn’t exactly have the words to describe it fully.
Understanding how to create the nutrition, as well as these side effects, helped give rise to what we call “brewing” today. We learned that wet grains were more easily fermented than dry. We learned that if the grains remains too wet they would rot and become useless. We also learned that adding certain botanicals to the process helped keep the resultant foods more stable.
Brewing raw materials such as malt, hops and the brewing water itself are infected by micro-organisms, and these have to be killed during the brewing process to prevent sickness and spoilage. [O’Rourke]
Each step in the brewing process has benefits. Each step brings something to the table, so to speak. The steps are, generally, as follows: malting, mashing, boiling, and fermenting. Let’s discuss each step in terms of how they provide benefits worth the trouble.
Malting
Malting is the partial germination of the grains to develop sugars and enzymes. I don’t think that our neolithic ancestors quite understood enzymes, but they certainly knew that malting the grains made them much sweeter than unmalted grains. They also surely understood that sweeter grains were more palatable. They also probably understood that germinated seedlings were sweeter than raw seeds.
An important step in malting is knowing when, and how, to stop the process. Allowing the grains to sprout into seedlings renders them useless for brewing. Somewhere between wet seeds and sprouted seedlings is when the malting process needs to be halted. This is after the enzymes needed for mashing have been activated, and some sugars have developed, but have yet to be used to create a new plant. It’s then the maltster will apply heat to dry the grains and prevent sprouting.
Over time, the malting process was refined to include the development of toasted malts, such as crystal, caramel, and chocolate malts. These darker malts add flavor to the brewed beverages because of the resultant Maillard reaction. The heat applied to the grains during this process may have a minimal side benefit of reducing microorganisms present on the grains.
Mashing
Mashing is the process brewers use to convert starches into fermentable sugars. As stated earlier, enzymes within the grains, developed during malting, are activated at specific temperatures. These enzymes break long carbohydrate molecules into shorter sugar molecules. Holding (resting) the wet grains (mash) at temperature promotes this process.
During mashing, the dried and crushed grains, now called grist, are added to hot water and steeped for a time to allow the enzymes to perform the conversion. Typical mashing schedules consist of one or more infusion of hot liquid to the grist. The main conversion, using beta-amylase enzymes, occurs in the range of 130-150℉ (54-66℃). There are additional enzymes that were activated during the malting process that can be utilized during the mash, provided the correct temperature ranges are achieved.
Alpha-amylase, active in the range of 150-160℉ (66-71℃), cuts larger strands of starch molecules. At 122-138℉ (50-59℃) and 113-128℉ (45-53℃), proteases breaks down proteins in the grain. This is helpful in developing clarity in the final beverage. Beta-glucanase is an enzyme that, in the temperature range of 95-131℉ (33-55℃), breaks down cell wall materials, which makes starches more available, thus raising the extraction efficiency of the final mash.
An additional benefit of the mash, aside from creating the sugars needed to feed the yeast during fermentation, is the destruction of heat sensitive microorganisms that are almost certainly present in the grist. Heat treatment is often referred to as pasteurization. The commercial rule of thumb has been to use a time-temperature relationship of 15 PU (pasteurization units). Since the mashing time and temperature generally used to achieve good starch conversion is about 1 hour at ~60℃ , we can consider the wort created during the mash to be pasteurized. [Driscoll]
Boiling
Boiling kills germs. We all know this to be true. What other benefits are derived from boiling the wort created by mashing? During wort boiling, the biochemical and physical reactions in wort give beer its characteristics flavors, color, and bitterness.[Tippmann] Boiling helps precipitate proteins from the wort, denatures any remaining enzymes leftover from the malting and mashing steps, and extracts the bitterness from the hops by isomerizing the alpha acids.
Just as enzymes are activated at certain temperatures, they can be switched off, or denatured, at certain temperatures. The continued action of enzymes after the mash will alter the fermentability of the wort. Large breweries will add a “mash-out” step, which will raise the temperature of the mash to a range of 168-175℉ (76-79℃). Home brewers will rely on the immediately subsequent boiling step to denature any remaining enzymes when a mash-out step is not used.
When hops are used in beer production, they are generally added to the boil. Boiling hops will isomerize the alpha acids, which are associated with bitterness. Iso-alpha acids are detrimental to certain gram-positive bacteria, such as Staphylococcus aureus, which causes certain infections like pneumonia, Streptococcus pyogenes, which causes rheumatic fever, and Listeria monocytogenes associated with meningitis. [Mokibi]
The use of other botanicals, such as mugwort, bog myrtle, and yarrow, traditionally used in gruit, may provide some level of protection from microbial organisms as well, although proper studies have not been done in this area. [Driscoll] When beer is produced without hops, such as ale and gruit, the production of the iso-alpha acids does not occur.
Boiling also concentrates flavors in the wort due to the evaporation of water. Any cook will know that putting a lid on a boiling pot will cause an overflow. It’s the same in brewing. Steam needs to escape, and in doing so reduces the level of liquor in the brew pot. This reduction of water causes the concentration of materials in the wort. Traditionally, high gravity beers, such as strong lagers and barley wines had a long boil time, the major purpose being the evaporation of water to concentrate the wort. [O’Rourke]
Fermenting
No one is denying that modern brewers are in for the alcohol. Alcohol, and its intoxicating effects, has driven humanity since its discovery. Beer, wine, and spirits wouldn’t be so popular without those effects. It’s quite possible that agriculture, and civilization itself, would have been far delayed without alcohol.
Cider,
cider,
the distillation of the forbidden fruit of Paradise
Full of the true, the blushful, Hippocrene,
with beaded bubble winking at the brim and purple stained mouth.
Cider,
loosens my libido,
transports me into realms of ethereal delights
and blows my cosmic mind – Yeah, woah too much [Wedlock]
Fermentation, specifically ethanol fermentation, during the brewing process creates ethanol alcohol (grain alcohol) and carbon dioxide (CO2)., which are both antimicrobial. The yeast involved is Saccharomyces cerevisiae, also called brewer’s yeast or baker’s yeast. Nutrients developed during the previous steps are quickly taken up by the yeast, which multiplies rapidly and crowds out other organisms.
Try as we might to eliminate it, there is always lactic acid bacteria (LAB) present in our environment. Without it, there is no sourdough, no kimchi, no sauerkraut. LAB serves us in so many ways to help preserve our foods. LAB will be present in the fermented beer as well, but that’s not necessarily a bad thing. LAB adds a sourness to beer by driving down the pH. This decrease in pH (under 4) and high abv (over 3%) work together to kill off unwanted bacteria, even in unhopped ale.[Driscoll]
Summary
It’s common to hear that our ancestors drank beer instead of water because beer was the safer option. We have seen here that the brewing process presents distinct hurdles for microorganisms to survive into the final beverage. Malting heats the grains, mashing reaches pasteurizing temperatures, boiling creates isomers that act against bacteria, and fermentation creates antimicrobial alcohol and CO2. These same steps also create nutrition, aroma, mouthfeel, and flavor. Through it all, a beverage is created that has been celebrated through the ages for its contributions to the quality of life (and afterlife, in some cases!).
Glossary
Adjunct – unmalted grains used in brewing
Barley – the key grain used in brewing
Diastatic power (DP) – measures a malted grain’s enzymatic content.
Grist – the ground grains to be mashed
Infusion – adding hot water to the grist
Lovibond – grain color scale
Malting – preparing the grains for mashing
Mash – the act of steeping the grist to acquire wort
Sparge – rinsing the grains with hot water
Wort – extracted liquid from the mashing process
Bibliography
O’Rourke T (2002) The function of wort boiling. The Brewer International:17–19
Driscoll, J. (2023). Driscoll. PhD Dissertation 2023. Strategic Drinking: The Archaeology of Alcohol in Early Iron Age West Central Europe
Gram-Positive Bacteria: Characteristics, Examples & Diseases
March 9, 2025 by Dr. Faith Mokobi
Gram-Negative Bacteria: Structure, Examples & Antibiotic Resistance
March 7, 2025 by Dr. Faith Mokobi
Tippmann, J. (2017). Kinetic studies of main wort flavor compounds and iso-α-acids during wort boiling: a review. European Food Research and Technology. https://doi.org/10.1007/S00217-017-2858-6
Wedlock, Fred, “Talking Folk Club Blues”, The Folker and Frollicks Album, Folk,©1966
No AI was used in the generation of this post.
©2026 Carrick MacSeáin
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