Grind City Coffee Expo 2022, DATA REVIEW FROM FRESHNESS EXPERIMENT

SEASON FIVE EPISODE ELEVEN - Grind City Coffee Expo 2022, DATA REVIEW FROM FRESHNESS EXPERIMENT 

This is the 11th episode of season five. This season was slated to lean science-heavy, and for the most part, it has been! We want to hear from YOU. When we start season 6, what would you like it to look at? Do you want more interviews and conversational pieces? How about deeper dives into aspects of the industry we have yet to cover? Have you enjoyed the science-driven episodes and want more? Let us know by visiting our website and filling out the forum, or just message us on Instagram. 

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For today's episode, we will be reviewing some of the data gathered from this year's Grind City Coffee Expo. If you were there and came to our booth, hello and thank you! It was a great day chatting up coffee with people, and so many attendees had kind things to say to us, which was quite encouraging. 

We also shared our booth with our friends at Boycott Coffee! It was a blast having them at our table serving up some exciting things they have been working on. We will be popped up in their space every Sunday from 10 am - 3 pm. Come by and see us?

 In true Sustain fashion, we set up a sort of experiment with three different variables to observe, the same as last year. We did not start off doing this the same as last year intentionally, however, it proved to be an engaging way for attendees to understand what we were trying to convey.

If you have been following along to the podcast and just our general conversations as of late, we have been quite fixated on the idea of coffee freshness post-roast. The majority of this year has been dedicated to this topic, and we have learned quite a bit about it. In case you missed the two-part episode, we encourage you to scroll back some episodes and listen to both episodes titled, "Uncovering the Science of Coffee Freshness". These episodes will explain in much further detail what we are going to be skimming over today.

Let's look at what expo attendees heard us say, prior to tasting the three samples provided.

Today we have an experiment set up for you to try. In front of you are three different samples. All of these are identical coffees, with an identical roast profile. The only difference between each sample is the date that the coffee was roasted. We have roast dates from two months, two weeks, and two days ago. The idea that we are trying to convey is due to the rising popularity of allowing the coffee to rest. This is where we state that freshly roasted (especially coffees on the lower end of roast development) should sit, untouched for at least several weeks before brewing should begin. One reason for this is that most light-roasted coffee is highly dense, and this density allows for greater amounts of Co2 to be trapped within the coffee, thus more time is needed for that Co2 to be released. But what does that release of Co2 do for our brews? The largest observation we have made is that after the first few days post-roast, the coffee takes a steep decline in the aroma as the initial Co2 is lost. Think of how when you first open a bag of coffee it is highly aromatic and quite pleasant to smell. After the coffee has rested for a week or more, that aroma begins to lose its viscosity. A normal first reaction to this loss of pleasant aroma is to view this as a negative thing. However, while the initial aroma may be diminished, we see an increase in complexity and stability. This is a large point for the argument in favor of resting coffee before brewing. While the coffee on day two has a high level of intensity and concentrated flavor, it lacks complexity and is one-noted in taste, and is very high in acidity. Resting for as short as two weeks, we can see a quick shift to balance, increased complexity, and a more rounded sweetness and clarity. For this experiment, the coffee that was two months off roast took the largest shift, it became more muted and developed a classic chocolate profile. This is to do with the roast profile, which for this coffee was around 11.5%. If the moisture content had been a bit lower, this likely would have tasted different, as well as potentially higher in complexity than the two-week sample. In case you are unaware, the lower moisture content is usually found in lighter roast/ less developed coffees.

After this short information dump, we provided a TLDR (too long, didn’t read) that was displayed on the table. Let's read that now.

HERE IS THE TLDR;

Lighter roasted coffees perform best after resting

High-density coffee + light roast profile = slower degas

Often degassing continues one month after roast (Co2 Loss)  

Allowing light roasted coffees to rest appropriately before brewing allows coffees to open up, tasting more round, transparent and structured.

Brewing too soon and we find that flavors are tight, restricted, and negatively influenced by trapped CO2 which gives way to inconsistent extraction.

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We learned with hindsight from last year that we should certainly be keeping on a log of what attendees voted as their preferences. We managed to gather responses from 133 individuals. Note that not every person who stopped by our booth had a chance to vote or a chance to hear the full explanation of the experiment, such is the nature of these jam-packed events.

The responses did leave one clear victor, but the numbers were closer than we anticipated!

The purpose of collecting our responses was so that we could have a glimpse into just how varied preferences can be, even when there is data pointing to one being objectively "better"

2 months had the response of 30% preferred 

2 weeks was the winning response with 42% preferred

2 days had the response of 28% preferred

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One interesting note we found, was that individuals who tried the samples from oldest to newest tended to have a preference for the oldest sample. Whereas those who tried the freshest sample first almost always chose the two-week or two-day option. Most all participants were easily able to detect the high levels of acidity and one-note taste that the two-day sample provided, without us prompting them to think so. When asked why each group preferred the sample they chose, here were the main responses.

Those who chose the two-month sample usually stated that it was softer and easier to drink. This sample took on an undeniable chocolatey texture, and those who liked that seemed to like coffee which was further developed. 

Those who chose the two-week sample argued that it maintained a superior balance in contrast to the other samples. Participants seemed to be able to detect specific taste notes rather than just over-arching explanations.

Those who chose the two-day sample could not get away from the preference for intense aroma. We found that those who preferred this sample voiced that they preferred it because of the intensity and overall mouthfeel experience. Those who chose this sample seemed to be highly resolved about their decision, while others tended to have trouble choosing which they liked best.