Yeast Before Beer: Does It Make A Difference?

The idea that eating yeast before drinking beer can reduce the effects of alcohol has been attributed to Jim Koch, the founder of Sam Adams. Koch claims that he has been eating a teaspoon of baker's yeast with yogurt before drinking beer for 10 years, and that it allows him to drink beer all night long and never get drunk. He learned this trick from the late biochemist and legendary brewer Joseph Owades, who helped develop low-calorie, light beers. While Koch's claim has been met with skepticism from the scientific community, some people have tried it out for themselves, with mixed results.

Jim Koch's method: swallow active dry yeast with yoghurt

Jim Koch, the founder and brewer of Sam Adams, has a unique method to prevent drunkenness. He mixes a teaspoon of active dry yeast with a small amount of yoghurt and consumes it before drinking beer. According to Koch, this practice helps break down the alcohol in the stomach before it can be absorbed into the bloodstream.

The science behind this claim involves the enzyme alcohol dehydrogenase (ADH), which is present in yeast, the human liver, and the stomach lining. ADH metabolises ethanol, the type of alcohol found in alcoholic beverages, into toxic acetaldehyde, which is then further metabolised into less harmful compounds.

However, the effectiveness of this method is disputed by some experts. Microbiologist Benjamin Tu argues that yeast prefers other sugars like glucose and maltose over ethanol. Therefore, the presence of sugars in beer and yoghurt might reduce the yeast's ability to break down alcohol. Additionally, the exposure time of the alcohol to the yeast in the stomach may be insufficient for significant breakdown to occur.

Despite the scepticism, some people have tried this method and reported varying results. While some experienced a slight reduction in drunkenness, others felt no noticeable difference. It is important to note that individual results may vary, and more scientific research is needed to confirm the effectiveness of this method.

It is worth noting that this method may not be suitable for everyone. For example, individuals allergic to alcohol should refrain from trying it as the ADH in yeast may not fully metabolise the alcohol before it enters the bloodstream. Additionally, it may not help prevent hangovers as the by-products of ethanol metabolism, acetaldehyde and acetate, are often blamed for hangovers, and the ADH in yeast does not aid in further digesting these toxins.

The science: alcohol breakdown in the human body

Alcohol is metabolised by several processes or pathways. The most common of these pathways involves two enzymes—alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). These enzymes help break apart the alcohol molecule, making it possible to eliminate it from the body.

When a person drinks an alcoholic beverage, about 20% of the alcohol is absorbed in the stomach and about 80% is absorbed in the small intestine. How fast the alcohol is absorbed depends on several factors: the biological sex of the drinker, the concentration of alcohol in the beverage, the type of drink, and whether the stomach is full or empty. Food in the belly slows down alcohol absorption.

After absorption, the alcohol enters the bloodstream and dissolves in the water of the blood. The blood carries the alcohol throughout the body. The alcohol from the blood then enters and dissolves in the water inside each tissue of the body (except fat tissue, as alcohol cannot dissolve in fat). Once inside the tissues, alcohol exerts its effects on the body. The observed effects depend directly on the blood alcohol concentration (BAC), which is related to the amount of alcohol the person has consumed. A person's BAC can rise significantly within 20 minutes of having a drink.

The breakdown, or oxidation, of ethanol occurs in the liver. An enzyme in the liver called alcohol dehydrogenase strips electrons from ethanol to form acetaldehyde. Another enzyme, aldehyde dehydrogenase, converts the acetaldehyde, in the presence of oxygen, to acetic acid, the main component in vinegar. The acetic acid can be used to form fatty acids or can be further broken down into carbon dioxide and water.

Much of the research on alcohol metabolism has focused on an intermediate byproduct that occurs early in the breakdown process—acetaldehyde. Although acetaldehyde is short-lived, it has the potential to cause significant damage, particularly in the liver, where the bulk of alcohol metabolism takes place. Some alcohol metabolism also occurs in other tissues, including the pancreas and the brain, causing damage to cells and tissues. Additionally, small amounts of alcohol are metabolised to acetaldehyde in the gastrointestinal tract, exposing these tissues to acetaldehyde's damaging effects.

Yeast's preference for sugars over alcohol

Yeast has an enzyme called Alcohol Dehydrogenase (ADH) that can break down alcohol. However, it is also responsible for converting simple sugars into carbon dioxide and alcohol.

Yeast has a preference for other sugars, such as glucose, maltose, and fructose, over ethanol. When these sugars are present, the yeast will turn off the genes needed for alcohol degradation. This is because yeast will always go for the sugar that is easier to break down.

In the case of beer, there are often leftover sugars that don't get fermented. If a person were to eat yeast with beer, the yeast would be more likely to consume the leftover sugars in the beer than the ethanol because they are more easily accessible.

Additionally, the exposure time of the alcohol to the yeast in the human digestive tract is likely too short for the yeast to have a significant impact on breaking down the alcohol.

The amount of time yeast is in contact with alcohol

Fermentation is a complex process where yeast interacts with wort or sugar to produce alcohol, carbon dioxide, and flavour compounds. The first 24 hours of this process is the growth phase, where yeast cells expand rapidly, absorbing oxygen, nutrients, and fuel for their growth. During this phase, carbon dioxide activity also increases, peaking near the point of peak cell growth.

After the initial growth phase, the yeast continues to be in contact with the alcohol as it works to convert sugars into ethanol. This can take several days, and the specific timeline depends on various factors, including the type of yeast, temperature, and air exposure.

In beer-making, brewers typically use Saccharomyces cerevisiae, which can tolerate an alcohol concentration of 10-15% before being killed. This is why the percentage of alcohol in beers is typically within this range. However, different strains of yeast can tolerate varying amounts of alcohol, so brewers can select specific strains to produce different alcohol contents.

While the role of yeast in converting sugars into alcohol is well-understood, the idea of using yeast to break down alcohol in the human body, as a way to mitigate drunkenness, is more controversial. Some sources suggest that consuming yeast before drinking alcohol may slightly slow down the absorption of alcohol, but the effect is marginal. Additionally, the yeast would need to be consumed with a food that does not contain other sugars, as yeast prefers other sugars to ethanol.

The effectiveness of the method: limited data

The effectiveness of eating yeast before drinking beer to prevent drunkenness is a claim that has attracted much attention and some scientific interest. However, there is limited data to support or refute the idea.

The claim that this method works is based on the understanding of how alcohol breaks down in the human body and the role of enzymes in this process. Alcohol dehydrogenase (ADH) is an enzyme that metabolizes ethanol (the type of alcohol in alcoholic beverages) into toxic acetaldehyde. This process occurs in the liver, but ADH is also present in the stomach lining. The claim suggests that ingesting yeast, which contains ADH, will increase the rate of alcohol breakdown in the stomach, resulting in less alcohol entering the bloodstream.

Jim Koch, the co-founder of the Boston Beer Company, is a prominent advocate of this method. He claims that ingesting active dry yeast mixed with yogurt before drinking alcohol allows him to "drink beer all night long and never get drunk". Koch credits this method to Joseph Owades, a fermentation expert and biochemist who patented the technique. Owades' patent application includes graphs showing a 28-38% reduction in blood alcohol concentration (BAC) attributed to the yeast.

However, the scientific community has largely reacted with skepticism to these claims. One key concern is that yeast prefers to break down sugars, which are present in beer and yogurt, instead of alcohol. Benjamin Tu, a microbiologist, states that the presence of these sugars will cause the yeast to "turn off the genes needed for alcohol degradation". In addition, Tu and others argue that the exposure time of the alcohol to the yeast in the stomach is too short for significant breakdown to occur.

Furthermore, the highly acidic environment of the stomach may also reduce the effectiveness of yeast ADH, which has an optimal pH of around 8.6. It is also important to note that only about 10% of alcohol breakdown occurs in the stomach, with the majority of the process taking place in the liver.

While there is some anecdotal evidence and limited experiments to support the idea, there is a lack of peer-reviewed scientific research on this topic. A small experiment conducted by NPR's The Salt blog found that yeast in yogurt had a minimal effect on slowing down alcohol absorption, while drinking a large amount of water before and between beers had a slightly bigger impact on peak BAC. However, these results are based on a small dataset and are not sufficient to prove the effectiveness of the method.

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