THE BREW CONTROL CHART

THE BREWING CONTROL CHART

We can understand the various relationships in coffee brewing mathematically. However, for many people, it is much more accessible and attractive to employ the Brewing Control Chart.

You will be asked a series of questions on your exam to determine whether different brews are ideal or not. You will be allowed to use a brew control chart for the exam.

BREW CONTROL CHART RELATIONSHIPS:

1. Solubles Concentration - Noted on the vertical (y) axis and marked as a percentage of the total dissolved coffee strength suspended in the beverage.
2. Coffee to Water Ratio - This we choose as part of our original brew plan. Each sequential coffee to water ratio is designated by a horizontal line where every point of intersection between concentration and yield form a solid oblique line intersecting the page diagonally. The coffee to water ratio need not be exactly 1:16 or 1:17, but it can be 1:16.5, etc. as you plan.
3. Solubles Yield - Noted on the horizontal (x) axis and marked as a percentage of the total percentage of coffee dissolved from the original coffee bed.
4. Ideal Zone - In the center of the chart we demarcate historic feedback from the work of E.E. Lockhart and the Coffee Brewing Institute where the sample population identified their "ideal coffee brew taste". The vertical range from 1.15% to 1.45% concentration and 18% to 22% for the ideal yield creates our target box. Measure your strength, find its intersection with the coffee to water ratio line, drop down to find your solubles yield and identify if you are in the SCA recommended brew target box.

The Brew Control Chart does not inform us if a coffee will be delicious. It just guides us where to start or how to seek correction towards a more tasty beverage.

REFRACTOMETERS

The first step to using the Brew Control Chart is to measure the coffee solubles concentration. This is done with a refractometer. Refractometers measure light refraction through a brew sample.

While it is not difficult to operate, there are some standard steps we should perform to yield accurate results.

1. Start with a clean, fully charged device. Tare the unit to zero using water or as directed with the instructions.
2. Allow coffee to cool to room temperature.
3. Stir the brew entirely before you take a representative brew sample.
4. If you used a metal filter media, such as a French Press or Espresso, then you should filter the sample before testing.
5. Use your pipette, or other, to place appropriate coffee sample onto refractometer and start.
6. You are encouraged to use the average of 3 readings from your sample.

NOTE: If your coffee is not room temperature, you will get wildly different readings from a brew sample. A hot beverage often measures much lower concentrations than one at room temperature. Therefore, seek a consistent routine and timed rhythm for taking your measurements.

Pro Tip!

One method that I use to both "stir" my coffee and assist it in cooling is to slosh it from one cup to the next. For example a fresh pulled espresso shot will be too hot - pour it into a cool latte cup, swirl it around and pour it back again. After a couple pours it will cool quickly from the air and expanded surface area.

SOLUBLES YIELD - EXTRACTION

On your exam you will be able to use a Coffee Brewing Control Chart to test yourself with the following measures.

[ 1 ]

If 42g of coffee is used with 700g of water and a 1.20% solubles concentration is reached, using the Coffee Brew Control chart what is the solubles yield?

• Take 700g / 42g to find your Coffee to Water ratio = 16.67
• Draw a new diagonal line from the top right corner for 16.67
• Find 1.2% concentration and draw a horizontal line to intersect
• Drop a straight line down from intersection landing on = 18.3% solubles yield

[ 2 ]

Using the Ratio Brewing Control Chart, if a beverage has a solubles concentration of 1.45% using a 1:16 ratio, what is the solubles yield? Is it an SCA ideal?

• drop a line from the 1.45% and 1:16 intersection to find 21%
• Yes, it is in the SCA Ideal target zone

MAINTENANCE & CLEANING

Brewing devices, servers, grinders and reusable filters must be cleaned to prevent undesirable taints in the brewed coffee and to extend the life of equipment. There are many benefits we achieve through good cleaning and maintenance:

• Better hygiene and safety
• Optimum coffee flavors and aromas
• Consistent operation of equipment
• Reduced faults in brewing
• Increased life span for equipment
• Better brand building and first impressions

Common points to pay especial attention to may include:

• Metal filters, such as in French Presses, can trap old grounds with rancid oil residues and off flavors
• Water towers out of use or neglected may hold stale water and need to be flushed or cleaned
• Water faucets and kettles where boiling or pouring create mineral deposits
• Auto Drip Coffee brew heads (showers) accumulate backsplash of grounds and oils. Remove, wipe and rinse.
• Coffee dispensers, urns and thermoses can be soaked with appropriate cleaners to remove old aromas and restore original surfaces
• Porcelain or glass brewers and service vessels may be bleached and scrubbed to restore original shine

And many more. Keep looking and you will find points to clean and maintain your safe, beautiful and hygienic coffee brewing program.

Great work!

You did it.

Move on to your mock exam to prepare for your future SCA certification.

~ Adam