How yeast affects the appearance of your beer

Man holding glass of beer

While flavour wins out at the end of the day, there’s no denying the pleasure of brewing a beer that looks as good as it tastes. If you’re like us, you’ve no doubt spent countless hours scrutinising the clarity, colour, and steady rise of bubbles from the depths of your glass. Beer’s aesthetic appeal is integral to the overall sensory experience, and it’s not all about grains and hops. Yeast plays a pivotal role in determining the clarity and appearance of your brew.

Yeast and Beer Clarity: The Tug of War

First, let’s explore yeast’s impact on beer clarity. Many factors can affect clarity, including the grain bill, hops, water chemistry, and brewing process. However, the flocculation of your yeast plays a significant role.

Flocculation refers to the behavior of yeast cells clumping together and settling out of the beer post-fermentation. Yeast strains vary significantly in their flocculation characteristics. Some strains, known as high flocculators, drop out of suspension rapidly, leaving behind a clear beer. Conversely, low-flocculating yeast strains may remain in suspension for longer periods, contributing to haze or cloudiness in the final product.

Like traditional British ales, certain beer styles benefit from high-flocculating yeast strains that deliver a crystal-clear appearance. In contrast, styles such as Hefeweizen or New England IPAs can benefit from a low-flocculating yeast to help with a hazy or cloudy appearance.

It’s crucial to consider that many factors can influence flocculation, including temperature, pH, alcohol content, and the presence of certain compounds (like zinc). As a brewer, you have a certain degree of control over these factors, thus allowing you to manipulate your yeast’s flocculation to achieve your desired beer clarity.

Yeast’s Influence on Beer Colour

Yeast doesn’t significantly affect the colour of your beer, as the hue is primarily determined by the malt used in the brewing process. However, yeast can subtly influence the perception of colour in your brew.

For instance, beers with a high degree of yeast in suspension (such as Hefeweizens) may appear darker or more opaque due to the yeast particles scattering light. On the flip side, beers that have undergone a thorough fermentation and maturation process with a highly flocculating yeast might appear lighter in colour due to their clarity.

Yeast and the Formation of the “Beer Collar”

One of the most visually appealing aspects of a freshly poured beer is the frothy head or “beer collar” that sits atop the liquid. This foam is the result of proteins and certain compounds in the beer interacting with the carbon dioxide produced by yeast during fermentation. The yeast strain, fermentation conditions, and the brewer’s practices can all affect this foam’s size, texture, and retention.


Though often unseen and unappreciated, Yeast is at the heart of the brewing process and significantly impacts your beer’s look and feel. By understanding and manipulating yeast behaviour, home brewers can take their beers to new heights, delivering brews that are not only delicious to taste but also a delight to behold. So, the next time you find yourself admiring a beautifully clear pint or gazing into the depths of a hazy brew, take a moment to appreciate the humble yeast. Its hard work makes all the difference.

Winter is here!

Colder weather definitely sends out in search of darker beers. This weekend, we went for one last time to enjoy the wonderful selection of beers crafted by Mitch and his team up at Newstead!

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