Evaluating Quality The quality of the coffee consumers drink depends on numerous factors, such as the [...]]]> In its January Volume, the Institute of Food Technologist featured an in-depth article titled Coffee Quality Testing. After explaining the coffee basics, the author relies on the expertize of our own Spencer Turer to explain how and why coffee is tested:

Evaluating Quality
The quality of the coffee consumers drink depends on numerous factors, such as the cultivar, growing altitude, climate, soil chemistry, harvesting and processing conditions, drying method, storage conditions (temperature, humidity), transportation method (container type and size), roasting conditions, grind size, packaging, age, and brewing method. Spencer Turer, Director of Coffee Operations at the independent coffee-testing company Coffee Analysts (www.coffeeanalysts.com), said that testing is conducted throughout the supply chain, but the amount of testing changes. Exporters and importers usually use basic sensory and physical evaluations to determine whether the product meets their quality standards for grade and are free of sensory defects. At the roaster, the testing becomes a lot more rigorous, and the regional, national, and multinational coffee companies become much more involved in dynamic quality control, using a variety of instrumental analyses as well as sensory evaluation. Turer said that although many strides have been made in instrumentation for flavor and aroma detection and identification, the simplest, least expensive, and most replicable results in coffee testing are obtained by sensory analysis, specifically the cupping method for flavor and aroma.

In this method, which is used at all stages of production, the taster or “cupper” first evaluates the overall visual quality of the beans (grading the beans for defects, size, moisture, aroma, and color), then roasts a sample in a laboratory roaster, grinds the roasted beans, and evaluates the roasted coffee fragrance. The cupper then adds boiling water to a standard amount of the ground coffee and allows the coffee to steep in the cup for about four minutes, smells the aroma, breaks the crust of grounds to complete the aroma evaluation, and then skims the floating grounds and oils from the top of the cup. After allowing the coffee to cool, the cupper tastes the beverage by forcefully slurping a spoonful to see if it meets expected standards, and then spits it out.

Using this procedure, the cupper can evaluate the coffee sample quality and blend different beans for product development or to determine the proper roast for specific flavor characteristics. According to the NCA, an expert cupper can taste hundreds of samples of coffee a day and still taste the subtle differences between them. Turer pointed out that the cupping process follows scientific protocols to ensure that the only variable in the test is the coffee being sampled. All aspects of the process are strictly controlled, including coffee roast parameter, time between roasting and cupping, grind size, coffee portion weight, water quality, water temperature, cupping vessels, and so on. The cupper records the intensity and quality of the dry bean fragrance and the aroma, acidity, body, flavor, and finish of the beverage.

Turer said that the physical laboratory tests that may be conducted on green coffee are density, moisture content and water activity, bean size, grade (defect counts), and color. Tests for roasted coffee are residual oxygen and carbon dioxide within packages, moisture content and water activity, roast color, grind particle size or broken bean counts, brewed coffee dissolved solids, pH, and Brix/refractive index. Chemical testing for coffee includes ochratoxin A, caffeine, nutrient analysis, microbiological analysis, and pesticides. Other tests that may be performed on roasted coffee are caffeine, chlorogenic acids, lipids, carbohydrates, total polyphenols, total proteins, and mycotoxins. Standard analytical methods for coffee have been published by AOAC International (see table), the International Organization for Standardization (ISO), and other organizations.

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Coffee Analysts now offers bundled coffee testing packages for green coffee and roasted coffee. These testing packages give you a comprehensive report [...]]]> Making consistently good coffee is all about setting high standards. The best way to do this is to test your coffee regularly to make sure it meets those standards. But where do you start?

Coffee Analysts now offers bundled coffee testing packages for green coffee and roasted coffee. These testing packages give you a comprehensive report of what’s happening with your coffee, from staling risks to taints to cupping scores.

Whether you’re a small roaster or a nation-wide retailer, there’s a testing package that can help you ensure the quality of your coffee.

Best of all, all coffee testing packages include Sensorial Analysis and a comprehensive report.

Prices vary depending on volume, quantity and your goals, so contact us for a quote.

Contact: 800.375.3398

More Info: Coffee Testing Packages

View over Lake Champlain from the cupping room

Cupping in the Coffee Lab

Don't let the view distract you

The Agtron uses near infrared light to analyze the color of ground or whole bean coffee. It then outputs an easy-to-read number that represents the degree of roast. The lower the number, the darker the roast. For [...]]]> The Agtron might sound like an agricultural superhero robot, but behind its name lies a simple coffee test: consistency.

The Agtron uses near infrared light to analyze the color of ground or whole bean coffee. It then outputs an easy-to-read number that represents the degree of roast. The lower the number, the darker the roast. For example, espresso roasts often have an Agtron reading in the 20s, dark roasts lie in the 30s, regular roasts between 40-55, and light roasts anywhere above 55.

Coffee Analysts uses the Agtron to determine roast consistency. We perform three Agtron readings for each sample to make sure they all fall within a certain range that’s determined by the customer. We then report all our findings back to our customers so they can adjust their roasting processes accordingly.

It’s all about consistency within a bag, and consistency from roast to roast. And the Agtron is the best tool to do test for coffee roast consistency.

Thank goodness for University of Vermont Adjunct Faculty Lecturer Colleen Armstrong.

Armstrong gets our [...]]]> While we can tell you anything and everything there is to know about coffee, when it comes to actually growing coffee from seed … well … we’re not exactly green thumbs. The problem is that we love having coffee plants around the office.

Thank goodness for University of Vermont Adjunct Faculty Lecturer Colleen Armstrong.

Armstrong gets our seeds going in the greenhouse so we have some foliage around the coffee lab. Without her, we’d be SOL.

Just don’t expect us to start brewing any of the office coffee plant bounty: a coffee plant needs as much as four years to bear fruit, and it takes 2000 cherries to make one pound of coffee.

We just enjoy the greenery. Feel free to come by anytime to see for yourself.

Some young coffee plants thriving thanks to Colleen Armstrong

Two year old plants in our coffee lab

Denser green coffees typically have more flavor of greater complexity [...]]]> At the Coffee Analysts Coffee Laboratory, we use a range of technical equipment to analyze the physical characteristics of green and roasted coffee. For all our coffee testing packages, we perform many tests, but there are few things in particular that we look for.

Density

Denser green coffees typically have more flavor of greater complexity and take longer to roast. Knowing the density is important to the roaster, especially if a dark roast is to be used.

Moisture

In green coffee, the moisture content affects how the coffee will roast, its flavor potential and potential for developing “off” flavors. High moisture content in roasted coffee can cause it to go stale prematurely.

Screen Sizing

A series of screens is used to determine the sizes of the green been sample. The size of the green bean an important indicator of quality and consistency.

Defect Inventory

Green coffee is examined for defects

A technician evaluates a weighed sample and classifies the defects according to standards used by the Coffee, Sugar, and Cocoa Exchange of New York and the Specialty Coffee Association of America.

Color Analysis

The color of roasted coffee is an important indicator of the degree of roast. A near–infrared or photo spectrometer is used to measure the color of the sample.

Oxygen

Any contact with oxygen will cause the roasted product to go stale. To help ensure the best vacuum packaging, Coffee Analysts takes a hypodermic sample of gas from the bag and tests it for oxygen content.

Grind—Particle Size

The coffee’s fineness or coarseness determines the rate at which flavor can be extracted from roasted coffee. We use a series of precision sieves and a vibrating plate to measure the size of particles in a sample.

Report on Sample to Standard

Using the above tests, Coffee Analysts compares a current sample with a set profile and issues a report. We can help develop a product standard for your target market or test to an existing popular product to determine a standard.

While some specialty roasters test every batch they produce, it often is unreasonable for [...]]]> Comprehensive coffee testing will help you understand how to source, roast and brew consistently great coffee. However, testing one sample one time will not reflect the state of your overall coffee program; it will only provide a snapshot of the particular sample.

While some specialty roasters test every batch they produce, it often is unreasonable for a roaster to go to extreme lengths to ensure quality. In our opinion, the key is to figure out a level of testing that can account for the variability of your coffee without blowing budgets and time constraints.

For example, if you know the quality of your green beans and your manufacturing systems (from production methods to roasting equipment) are dialed, less testing may be required. However, if you just got a new roaster or you’re experimenting with a new source of green beans, it is often best to over-test at first until the level of variability is known. At certain times during the crop year, the green beans can show more variability; at these times more testing is necessary.

At Coffee Analysts, our clients typically have their products tested monthly, quarterly, and for those with the highest standards of quality even weekly. We offer discounts for these types of testing packages. However, we’re also happy to give you a snapshot of your roasted or green coffee by doing a one-time test.

But in order for the coffee to come out just right, the correct brew parameters must be in place: water quality, water-to-coffee ratio, water temperature, and grind. [...]]]> When coffee is brewed correctly, there is truly nothing like it. You do a double-take, look incredulously at the cup in your hand and say, “man … that’s GOOD.”

But in order for the coffee to come out just right, the correct brew parameters must be in place: water quality, water-to-coffee ratio, water temperature, and grind. When brewed correctly, the coffee’s best flavors are released quickly, and bitterness will be present, but it will be perceived as more of an aftertaste or “finish.” Cutting off the extraction at a certain point can control the amount of bitterness.

The ideal cup

However, when coffee is brewed poorly, you can be left with a weak or bitter or *gulp* weak AND bitter cup of coffee.

Water Not Hot Enough

If the water is less than 190º F., the best flavors are not extracted, but the more soluble bitter flavors will be. The product will taste weak and bitter.

Water not hot enough will lead to bitter, weak coffee

Water Too Hot

If the water is above 205ºF, all soluble material, including less desirable material, is quickly extracted, resulting in a strong bitter cup.

Water over 205F results in strong, bitter coffee

Coffee Grind Too Fine

When the coffee is ground too fine (particle sizes too small), the best flavor is quickly extracted. More of the bitter flavors will also emerge after the better flavors have been washed out.

Too fine of grind leads to bitter coffee

Grind Too Coarse

When the coffee is ground too coarse (particle sizes too large), the brewing process proceeds slowly. The best flavors are not dominant and the cup will taste weak and somewhat bitter or astringent.

Too coarse of grind results in weak coffee