In the second of our series on sensory testing, we look at how larger brewers with mutli-site operations can use a systematic approach to tasting to ensure consistency.

In the first article in this series, we looked at the complexity of taste, and how to begin implementing a sensory testing-based approach. In later articles, we’ll look at two distinct areas of brewing, craft brewing and no-/low-alcohol, where there are specific challenges to the standard approach. Before that, we will consider some of the ways the world’s biggest brewers use sensory testing, to ensure consistency between sites and across time. We’ll be guided by two experts, Genevieve Upton of Cara, and Tom Brown of FlavorActiV.

Training your senses
At the heart of both Cara’s and FlavorActiV’s approach are flavour standards, sold under the Aroxa brand by Cara, and as GMP Flavour Standards by FlavorActiV. The starting point for training is to dilute one or two of these stable compounds with a litre of water.

“Our capsules are about three times the flavour perception threshold when you add them at one capsule per litre,” Upton says. “Generally we will train people at two capsules per litre the very first time we introduce them to a compound, and it’s because we don’t want to leave anything up to chance.”

As we learned in the first article, we each have our own tasting capabilities, and are often nose-blind, or anosmic, to individual flavours. By starting with an intense burst of flavour, trainers can spot participants who may have a relevant anosmia.

The panel leads will then move to lower concentrations in water, and in beer. “You’re not going to find that flavour at that exact level all the time,” says Brown. “It’s trying to make it stronger initially, and then drop it down.”

Validating your senses

Learning to identify flavours, at decreasing concentrations, is the first step in a systematic approach to sensory testing. But this is a skill that must be honed with time, and that can be lost.

There are a number of factors that can impact our ability to taste. “Health conditions can have a big impact on a taster’s capability,” Upton says. “Pregnancy, COVID, medications for diabetes can change how your body perceives taste.”

To combat this, Cara offers a validation programme. This is based on a set of flavour compounds relevant to the brewery. “We send them a completely blind pack, maybe four or six times a year,” Upton explains.

This double blind testing—where even the team running the panel does not know which compounds are being used—can be used for a simple stop-go evaluation, for a recognition test, or a rank rating, where testers judge the intensity of each flavour.

A sensory testing company can then evaluate each panel’s responses, and suggest changes or training needs. “You’re looking at the performance of the whole panel,” Upton says. “It’s not just can they identify a flavour or not, the outcomes of the validation session will show what they’re struggling with, common confusions, and will direct their training. It also lets them see if a health condition has impacted a taster’s capabilities.”

Validation is particularly important for international brewers, Upton says. “It means we can compare the sensory panel that’s sitting in the UK, to an expert panel sitting in Central Europe, to one in Canada, because they’ve all been sent the same pack.”

Human machine interface

Skilled tasters can detect flavours and their interactions in ways that machines can’t. But that doesn’t mean that instruments don’t have a role to play. Alongside its compounds and training, FlavorActiV offers equipment including the Micro ESR, for measuring freshness, and the Electronic Nose, which can detect multiple aromas at once.

“The Micro ESR detects the levels or free radicals, usually in beer, but also in cider and juices,” Brown says. “From that, you can then predict the shelf life.”

“The beauty is that it can take samples in process,” Brown explains. “If you are detecting high oxygen pick up in one area, you can make sure that is resolved, so those high oxygen levels are not carried through the process.”

Informing quality

Both of the flavour compound providers we spoke to work around the world. “They produce millions of litres of beer,” says Brown, “And they want their global brand to be consistent.”

For a brewer like this, a recall does not just mean lost production, it can mean a damaged reputation. It’s not always down to an error in the brewery: long supply chains to retailers and bars can lead to quality issues.

“Some of the bigger breweries,” Brown says, “Will take products back from the market, and do further sensory testing to ensure they are as intended.”

Sensory testing can be used within breweries as part of internal quality control. “Ongoing monitoring ensures the beer is always the same,” Upton explains. “Sensory testing panels can work with technical brewers, to take the information they’re learning on a specific beer produced at each site, and to root cause any changes.”

Defining good taste

Many multinationals will seek to offer a consistent taste globally. Others may adapt a recipe slightly to match local tastes. For both approaches, Brown says, a standardised approach to testing is key.

And this programmatic approach can go further, Upton says, feeding into marketing and R&D. “If you’ve developed a brand new beer from scratch, part of the product development pathway will be defining what good looks like. And part of defining what good looks like is more than just the analytical breakdown,”  says Upton. “It’s looking for something that fills this specific flavor white space within a portfolio.”

Marketing departments, R&D teams, and brewers will all have a role to play here, supported by the sensory testing panel. Whether to define what is good for a new beer, or to maintain it for a globally loved favourite, that panel is key. “They are there profiling and looking at drift and they’re looking at the intensities of characteristics, they’re looking at the presence of those characteristics in relation to each other,” says Upton. By defining a profile like this, the panels and their colleagues across a brewery, can put a name to what it means for a beer to be good.

And while the multinationals may have more resources for systematic programmes of testing, these principles can be adopted and implemented at craft brewers with a rapidly changing product line up. We’ll learn more about how they can do so in next week’s article.