Booze School: Lesson 1 - The Science Of Tasting Beer

Tasting Beer

There is a distinct difference between drinking beer and tasting beer.

Drinking beer is easy! 

Tasting beer on the other hand needs training and practice. With tasting, the goal is to pick up all the characteristics of the beer and evaluate it.

There are rules we must follow in order to properly evaluate beer. This ensures we’re giving each beer a level playing field and allowing each beer to shine in the way the brewer intended.

First rule is glassware,

Having the right glassware makes a massive difference in your sensory experience. There are many different types of glassware that suit different styles. However the main rules for tasting glassware are:

     1 - Use a “Bowled” glass, like a white wine glass or tulip glass.

     2 - Don’t fill the glass more than a third full.

Following both these rules allows the aromas to be captured better within the glass and not let them escape before we get a chance to evaluate them.

The next rule is temperature

Serving the beers at the correct temperature further enhances the sensory experience.

The general rule of thumb is lower alcohol beers should be served at lower temperatures. Higher alcohol beers should be served at warmer temperatures. The graph shown is the optimal serving temperatures for those styles.

As a heavy dark beer like an imperial stout warms us to room temperature, it opens up the beer allowing for a deeper more intense sensory experience.  Next time you have an imperial stout, try taking it out of the fridge an hour or so before you drink it.

Tasting like a beer judge

There are seven steps to the tasting process.

Tasting Diagram

Figure 1:  Tasting Beer (2nd Edition): An insiders guide to the worlds greatest drink, Randy Mosher, 2017

1 - Tabletop

While the beer is sitting on the table, can you smell anything?

2 - Drive by

Lift the glass up and move it past your nose while inhaling.

Beer contains lots of delicate and extremely volatile compounds that evaporate quickly. These compounds are best smelled at a distance.

3- Swirl

4 - Short Sniff

The ‘Swirl’ and ‘Short Sniff’ steps work hand in hand.

Swirling the beer allows compounds and aromas to be released into the glass.

To perform the short sniff, pull your glass right up to your nose and take multiple short, sharp, sniffs. Think like a bloodhound sniffing for drugs, the same processes are taking place.

By using short, sharp, sniffs we are opening up our olfactory and allowing more aroma into the nose.   

5 - Look at the beer!

We often drink withT our eyes. The more pleasing a beer looks the better it will taste, we’re also looking to see if the beer looks to style. Look for colour, clarity and head retention.

The reason we evaluate smell before looking at the beer is so we don’t lose any of those important but highly volatile aromas in steps one and two.

6 - Taste the beer!

Take a sip, pay attention to how the beer changes in your mouth. Firstly the acidity, then the sweetness, and finally the bitterness. Bitterness in hoppy beers can take a while to fully evolve, allow the beer to sit in your mouth for a bit. Take your time.

We are also evaluating mouthfeel at this point. Look for the carbonation, the thickness or body of the beer and finally is there an oily slickness (we’ll talk more about oily slickness later)

Swallowing is also incredibly important (unlike in wine tasting) as there are bitterness receptors in your throat and stomach!

7 - Retronasal Olfaction (The Final Step)

As you swallow, breath out through your nose with your mouth closed. Once in your mouth, the beer gets attacked by enzymes in your saliva releasing even more aroma. As you breath out your brain fuses these aromas and the tastes on your tongue to produce even more depth to the flavours!

Tongue Map

New Tongue Map

Figure 2:  Tasting Beer (2nd Edition): An insiders guide to the worlds greatest drink, Randy Mosher, 2017

Let's look that the basic tastes:

  • Sweet
  • Sour
  • Salty
  • Bitter
  • Umami
  • Fat
  • And more!


Sweetness is probably the most familiar sense to everyone. Sweetness in nature was used as an indicator of something with a high nutritional content, like fruit. The genetic wiring in our brain craves sweetness.

All beer has an element of sweetness and comes from the malt we use in the brewing process. When brewing we break down long starches into smaller sweet sugars. These sweet sugars are fermented into alcohol but often some remain. Giving the beer an inherent sweet character.

Sweetness is often used to balance hop bitterness. Higher bitterness levels require higher levels of sweetness in order to remain palatable.


Sour sensors in our mouth detect hydrogen ions, as all pH meters do. Sourness in our genetics is used to indicate the ripeness of fruit and is also a marker of spoiled foods (such as milk).

All beer is moderately acidic, with most having a pH of 4-4.5. With the exception of “sour” beers acidity plays a supporting role, boosting other flavours within the beer.

In “sour” beers such as fruit beers and lambics, the sourness plays a starring role. The sourness amplifies and brightens the fruit character.


These taste buds respond to sodium ions, which are an important part of our diets. Saltiness does not place a common role in beer other than boosting other flavours within the beer.


Bitterness in nature was originally only found in toxic chemicals, and as such the body has a lot of defence mechanisms to fight against bitterness. As plants evolved however, some plants such as hops developed bitterness compounds without the toxic chemicals as part of their defence mechanisms.

In brewing, we use bitterness to help balance the malt sweetness and add a refreshing quality.

As stated before, bitterness can take a while to build on the tongue and in the mouth. So in a 40 IBU beer and a 120 IBU beer the first 5-10 seconds taste the same. However the 120 IBU beers bitterness grows later in the palate.

Our perception of bitterness is only accurate to about 20% (even in trained tasters). So a 40 IBU beer’s bitterness will taste almost identical as a 50 IBU beer when tasted side by side.

Slide 11: Umami & Fat

Umami (which translates to deliciousness from Japanese) was only discovered to be a taste receptor in the year 2000. Umami sums up the savour, meaty quality in food and occasionally beer. Umami in beer is most notable in aged beer. First showing itself as a rich meatiness, then with notes of soy sauce.

Fat doesn’t play a role in the beer tasting world as beer is a fat free product.

Aroma and Olfaction

As aromas travel into our nose they trigger responses from sensory cells embedded in the upper part of the nostril. The Olfactory system is the name given to these sensory cells and the connections they have to our brain. Humans have 20 million olfactory sensors, which seems a lot but compared to other animals is a relatively small number. Dogs for example have around 200 million and bears even more!

Humans have about 1000 different receptor types all of which can sense a wide range of different aromas. Recent research suggests we can sense 1 trillion or more different aromas. Our ability to identify and describe these aromas however, is vastly less proficient.

Olfaction is wired differently to every other sense. Rather than going directly through the Thalamus to the brain, first it goes through the Hypothalamus, Hippocampus and Amygdala. These extra steps jumble up the signal, making it hard for us to break down aromas. 

However they often trigger emotions and memories. We naturally assign emotions and memories to different smells and we can use these triggers to help us describe the aromas. Think grandma’s kitchen, fresh cut grass, or even the smell of tequila and that night out where you drank too much. This is what makes aroma so powerful!

The Beer Flavour Wheel


So far we have learnt how beer judges taste beer, how our body works, now let’s learn how to put it into practice. We can use the beer flavour wheel as a reference to help us describe beer and it’s unique qualities. In the middle of the wheel we have the basic terms, the middle is the categories of terms and the outer edge are more in depth terms we can use to further differentiate flavours.

Beer Flavour Wheel


Figure 3: Beer Flavour Wheel,

Use the flavour wheel as a jumping off point and as you experience more flavours you’ll be able to expand outside of the flavour wheel!

Off Flavours

Off Flavours are flavours that are deemed undesirable in beer. The majority of off flavours come from the brewing process, but some can come from how we serve the beer or store the beer.

Some off flavours are acceptable in certain styles while not acceptable in others.

Today we’re going to talk about 2 of the more common off flavours and we’ll talk a little bit on how to avoid them.

DMS (Dimethyl Sulfide)

Type: Aroma
Flavours: Creamed corn, cabbage, vegetal, green beans, canned asparagus and tomato juice.
Threshold in beer: 30 to 50 µg/L
Appropriateness: Usually not but is acceptable in small amounts in lagers

DMS is a flavour compound considered an off-flavour in beer at high concentrations (max 30 micrograms per litre)

DMS is mainly produced by the thermal decomposition of SMM (Sulfur Methylmethonine). SMM comes from the embryo of barley during germination and is readily dissolved during the mashing process.

As DMS is a naturally occurring compound found in every beer, there are a couple of techniques we can use to reduce the amount of DMS to an acceptable level.

One of the main techniques is a long vigorous boil. As the wort boils DMS is evaporated. The more vigorous the boil the more DMS is evaporated.

We can also avoid excessive DMS production by rapidly chilling the wort after the whirlpool/hopstand stage of the brewing process.

Lightstruck (3-Methyl-2-Butene-1-Thiol or 3MBT)​

Type: Aroma
Flavours: Skunk Spray or Rubbery
Threshold in beer: 0.05 µg/L
Appropriateness: Never

Lightstruck beer is a reaction between blue or UV light and chemical compounds in hops called isohumulones. Isohumulones are the bittering compound in hops and are found in every beer. The blue or UV light converts the isohumulones into 3MBT. 

3MBT is the exact same compound that skunks produce to create their defensive spray. Which is what gives lightstruck the nickname “Skunked” beer.

So how do we protect beer against getting lightstruck?

Firstly we must ensure the beer is properly stored, make sure you aren’t leaving any beer in the sun. Secondly breweries use different coloured glass bottles in order to filter light more effectively. Brown bottles are best and green bottles also work well. Or you could go the way of most craft breweries and utilise cans to protect against lightstrike.

As a bottle store all of our fridges also have a UV film over the glass in order to reflect the UV light.


Further Reading:

Tasting Beer (2nd Edition): An insiders guide to the worlds greatest drink, Randy Mosher, 2017

Close (esc)


Use this popup to embed a mailing list sign up form. Alternatively use it as a simple call to action with a link to a product or a page.

Age verification

By clicking enter you are verifying that you are old enough to consume alcohol.


Shopping Cart

Your cart is currently empty.
Shop now