On The Table: Phenols & Terpenes

Phenols are a category of aromatic, flavour-active compounds that are produced by certain species of yeasts as a survival mechanism, similar to how plants produce certain chemicals as defence mechanisms. In large-scale commercial breweries, these flavours are considered to be off-flavours. These off-flavours can be described as clove, herbal, peppery, bubblegum, banana, spicy, smoky, and at their worst, medicinal or “band-aid”-like. However, they are common in classic farmhouse breweries of Belgium and Europe at large, and are an essential characteristic of famous Belgian styles, such as wheat beer, table beer, abbey-style single, dubbel, tripel, quadrupel, Belgian-style blonde ales, and more.

Here is a list of the different flavour-active phenol compounds and their associated flavours (source):

​Chemical Compound	Associated Flavour
4-Vinyl Guiacol	Clove, curry, spice, smoky, bacon
4-Vinyl Phenol	​Phenolic, medicinal, spicy
4-Ethyl Guiacol	​Clove, phenol, spice, woody, smoky, vanilla
4-Ethyl Phenol	Leather, phenol, spice, stable, smoke, creosote
​Guaiacol	Smoke, bacon
​Vanillin	Sweet, vanilla

Now to briefly mention another type of flavour-active compound present in beer: Terpenes.

Terpenes are a category of hundreds of plant-based, flavour-active, aromatic chemical compounds that can be found in hops, cannabis, citrus rinds, and peppercorns, to name just a few of the things they are naturally present in. Hop-based terpenes contribute greatly to the flavour profile of any beer, and are largely responsible for the intense woodsy, herbal, citrus, and fruit flavours and aromas found in heavily-hopped IPAs. Examples such as myrcene, linalool and limonene are terpenes found in szechuan peppercorns, and have intense flavours of ripe tropical fruit, wood, and spice, which is why we added them to our 325 Table Beer.

Terpene	​Associated Flavour
​Myrcene	Citrus, clove, earthy, fruity, green, vegetal, mango
Limonene	Citrus, rosemary, juniper, peppermint
​Caryophyllene	Spicy, sweet, woody, clove, camphor, pepper
Alpha-pinene	Pine needles, rosemary
Beta-pinene	Dill, parsley, rosemary, basil, yarrow, rose, hops
Terpineol	​Floral, lilac, citrus, apple/orange blossoms, lime
Borneol	Menthol, camphor, pine, woody
Delta-3-carene	​Sweet, pine, cedar, woosy, rosemary
​Linalool	Floral (spring flowers), lilly, citrus, and candied spice
Pulegone	Mint, camphor, rosemary, candied spice
Eucalyptol	​Spicy, camphor, refreshing, rosemary
Farnesol	Floral, muguet, lily, tuberose, rose, musk, acacia, lemongrass, delicate, mild, sweet
Nerolidol	Woody, fresh tree bark, floral, green, waxy, citrus
Humulene	Vietnamese coriander, hops, woody, clove

(source)

In our 325 Belgian-style Table Beer, we used a yeast strain (Wy1214) that originated in the Chimay brewery in Belgium. It is famous for its phenolic character, as well as its ester profile of red fruits and plums. These yeast-derived flavors of clove, pepper, bubblegum, and red fruits, mingle with citrus-forward terpene-based flavours (from terpenes such as beta-myrcene, geraniol, limonene, cineol, and citronellal, plus many more) from the coriander, white pepper, szechuan pepper, and mandarin peels.

Are you still wondering what a “Table Beer” is? Originating in western Europe, it was historically a common, low-strength wheat ale, good for drinking at all times of the day, with ever-present phenol character from the local yeast strains. A commercial example might be a low-strength version of Blue Moon Belgian Wit, or Hoegaarden. Our version of Table Beer is a similar type of beer, but with the citrus element amped up exponentially using lots of different plant-based sources for those sweet, sweet terpenes. Personally, this is one of my favourite styles of beer. I think the flavours mingle perfectly, and I am very excited to share it with you!

Written by:

Ryan, Brewer @ Faculty.