Hops are mainly responsible for the bitter flavours found in beers
Describing something or someone as bitter is not deemed a particularly positive attribute.
Bitter cold, the bitter truth, leaving a bitter taste, having to swallow a bitter pill, fighting to the bitter end are idioms that evoke distinct unpleasantness.
As a species, human beings have learned to equate bitter flavours with things at are unpleasant or even harmful. We have evolved to taste bitter as a warning sign of something potentially dangerous and rightly so, as many highly toxic substances taste bitter.
Alongside our ability to detect sweet, salt, and sour we consider bitterness as one of the primary elements of taste. As our understanding of how our bodies and brains detect and decode taste and flavour biologically and chemically, our understanding of the basic building blocks of taste is expanding to include other primary elements. These include umami, that distinct savour y taste found in foods such as soy sauce and mushrooms and even carbon dioxide, which can indicate fermentation.
Depending on an individual’s genetic make-up, people detect bitterness more intensely. Some people are not able to taste bitter flavours at all while others find bitter compounds incredibly unpleasant.
It is believed that the ability of taste bitterness evolved over millennia and served as a means of protecting early humans from eating harmful foods.
As we age our likes and dislikes regarding food change, which explains why as adults, we often find our favourite childhood treats far too sweet. As we mature, our tolerance for bitter flavours develops and even people who are very sensitive to bitter can acquire a taste for foods such as, dark chocolate, coffee, dark green vegetables and the hops used in beer.
Bitter flavours find a counterpoint when paired with things that taste sweet, and in beer, we find the perfect marriage of sweet and bitter.
The backbone of a balanced, well-made beer is the malt from which it is brewed. Malt is deliciously sweet but, on its own, the appealing maltiness can soon become cloying, difficult to drink and reminiscent of too many cups of Ovaltine.
Yet, paired with aromatic bitter hops, the beer will taste balanced and moreish.
The bitterness from the hops enhances drinkability, while the sweetness from the malt balances the hops.
Considering the standard measure for beer is a pint, drinkability and balance plays a very important factor in enjoying a beer.
Ideally a beer should taste good from the first sip to the last drop. As a beer warms up during drinking, flaws which may have been subdued at the original cooler pouring temperature may become more apparent.
A well-balanced beer should retain its drinkability as it warms ups and the flavours and aromas of the beer become more pronounced.
When measuring bitterness, IBU International Bittering Units are used; this is the measurement of how bitter on a scale of 1-100 a beer is.
From a technical perspective, IBU gauges the isomerized alpha acids from hops in a beer in parts per million.
Very hoppy beers, such as imperial IPAs, can reach 80 IBU. Not all beers include the IBU on their labels but this measurement can help consumers identify how bitter a beer will taste and is especially useful for people who are sensitive to bitter flavours.
Knowing the IBUs can help you better understand what type of beer you like in terms of bitterness but it is important to note that beer with a high IBU, like stouts, might not taste very bitter at all because of their sweet malts or use of unfermentable sugars such as lactose.
Taking all aspects of a beer into account the IBU number can be help gauge your preferences.
Identify the IBU of your favourite beers will help you identify what range your favourite beers fall into and what styles of beer you enjoy best.
Judith Boyle is a qualified chemist (MSc) and accredited beer sommelier. Susan Boyle is a playwright, artist and drinks consultant. See www.awinegoosechase.com.
Both sisters are proud to be fifth-generation publicans. Their family business is Boyle’s bar and off-licence in Kildare town