Expand your Coffee Expertise! Part II Guide for Making a Perfect Cup at Home

The first article “Become a Coffee Expert! Guide for Making a Perfect Cup at Home” describes the basics of making an optimal cup of coffee.

Once your coffee seems balanced or just OK, there are several ways to make further improvements. Every coffee is unique and the Perfect Cup doesn’t necessarily reside within standard brewing values. Qualities like body, brightness, finish, aroma, etc. can be improved, even if the test cup seems to be already good enough.

Ways of Improving Your Optimally Brewed Coffee

For example, you got your optimal cup at a 1:17 coffee/water ratio, a grind of 20 units and 2 ½ minutes brewing time at 90-93 (degrees) C. The acidity is good, the aroma is present, there is a hint of bitterness, and it is sweet enough. Almost always, however, any cup of coffee can be improved. Remembering the basic extraction formula: “oils/acids-sugars-bitterness” you can make it bright (more acidic), sweeter, more aromatic, and equally bitter. To achieve this, try increasing the coffee to water ratio to 1:16, or even 1:15. What is is going to do?

If you are brewing immersion type (French press or Aeropress), you will extract more of everything. The coffee will be more aromatic, acidic, sweet, bitter and with more body. To cut down on bitterness, all it takes is to slightly reduce the brewing time, five seconds may be sufficient.

If you are brewing infusion type (espresso or pour over), using less water will automatically reduce contact time, and hence, bitterness. This is almost like the idea of a ristretto coffee: a smaller, sweeter and more aromatic shot without any bitterness.

Ristretto Coffee

Ristretto is not a kind of under brewed espresso coffee. It is a version of a perfect brew, but without any bitterness. This is achieved by letting less water pass through the coffee bed. Ristretto is about a 1/2 to ¾ size of regular espresso.

Also it has a higher concentration of oils, acids and sugars. This is because the brewing is stopped once all (or most) of the sugars and oils extract; and just before any bitterness leaches out of the grounds. The same amount of oils and sugars diluted in less amount of water produce a sweeter and tastier coffee. Ristretto will have slightly less caffeine than regular espresso. It goes well in lattes and cappuccinos because it has no bitterness and less water.

If you are brewing with any other method than espresso, eliminating the bitterness in lattes and cappuccinos is a good idea anyway. Coffee beverages containing dairy milk taste better when the shot is bright, aromatic and oily. It doesn’t necessarily need to be sweet and it definitely shouldn’t be bitter. So, for lattes and cappuccinos, make sure you stop the brewing process well before any bitterness shows up.

Super Ristretto Coffee

If you want to cut down on caffeine, try brewing (or ordering) a “super ristretto” for your cappuccino or latte. A super ristretto uses even less water than a regular ristretto, about 30% of an espresso volume. It will have pretty much all the oils and about half the caffeine of a regular espresso shot.

It will have very little sugar, so it is not good for having “as is”. However, it will not matter if you have it with milk, which contains enough sugar in itself. So, instead of a ristretto shot in your latte, try a “double super ristretto” one. This will give you approx. the same amount of caffeine, but almost double the amount of oils and flavors.

Also try super ristretto over dairy ice cream. Without changing any settings on the espresso machine, a super ristretto can be brewed by stopping a regular espresso about 1/3 into the brewing process. If your machine doesn’t have a “stop function”, you can simply remove the cup at the right moment and let the rest of the beverage drain.

Water TDS and Why it is Important

The importance of water quality was already touched on in the first coffee article. Water from different sources usually has a very different composition. This is why water can be hard, soft, alkaline, acidic, etc. To simplify the water selection for your coffee, there is one important measurement called TDS. It stands for Total Dissolved Solids (TDS) and is usually measured in parts per million (ppm). TDS simply indicates the amount of soluble matter dissolved in the water.

Pure distilled water ideally has a TDS of zero. Water recommended for drinking will have a range 250-500 ppm. Water that is below 250 ppm or above 600 ppm is generally considered not so good for regular consumption. The former is considered under mineralized, and the latter – over mineralized. This is very simplified because it is also important what particular solubles are in it. It is also very possible that a particular person will benefit from water with a particular composition. It can also vary from the ideal TDS, since everyone is different. So, TDS tells us how much of any kind of solid matter is in our water altogether.

The ideal water for coffee brewing is not within the drinking water recommended range. It is somewhere between 50-250 ppm, however it is best not to go above 150. Coffee brewing water TDS is important because coffee is essentially a solution. The higher the TDS of our brewing water, the “harder” the extraction will be. It is like trying to run through a crowded street, it is not easy to gain speed and avoid bumping into someone. On the contrary, a low TDS water provides a lot of “room” for acids, sugars, etc. to dissolve easily. Water in the range of 50-150 ppm is a “green light” for coffee extraction.

What it means practically? It means that a low TDS water will make a sweeter coffee with a more complex taste than a high TDS water. Remember the basic coffee extraction formula: “oils/acids-sugars-bitterness”. High TDS water will likely allow most of the acids and oils, but will somewhat block the remainder of the acids and some of the sugars. In other words, coffee made with high TDS water will be somewhat under brewed. This is especially true if you brew at higher coffee to water ratios, like 1:15.

The tricky part is that you can hardly fix it by brewing longer, grinding finer, etc. This will usually result in an over brewed bitter coffee anyway. The amount of extracted bitterness doesn’t seem to be influenced by TDS as much as the amount of sugars. So with high TDS water it is not easy to brew a balanced cup.

Very low TDS water (below 50 ppm) is not recommended either. It will neither benefit the taste, nor your health. Such a coffee will lack taste, because water does contribute to it. Water that is too low on minerals doesn’t taste good. This is why water obtained from reverse osmosis units or any other kind of distilled water shouldn’t go into coffee. Such water must be re-mineralized in order to reach the target 50-150 ppm value. Water low on minerals, as well as very hard water, can also be harmful to the precision parts of coffee machines. It will either eat out metals, or leave excessive scale.

An optimal TDS will also improve the body of the coffee. Body, or fullness and richness, depends on how much soluble matter is extracted from the beans. Also, it depends on the body of the water itself. An optimal water TDS will not only ensure that water has enough of its own body; it will also make space for the coffee beans to provide body to the coffee.

You can take a precise water TDS measurement with a TDS meter

Brew with Different Coffee Beans

To give an example, if your test cup is brewed with a medium roast, try a light or dark roast. Light, or blond roast, will give more brightness, or acidity. Darker roasts will provide more traditional strong and caramelly coffee flavors.

Brew with a Very Different Coffee to Water Ratio

To give an example, your optimal cup is: Lavazza medium roast, grind size 20 (Baratza scale), coffee-to-water ratio 1:16, 3 minutes in a French press. Try drastically increasing coffee to water ratio, let’s say to 1:10. So, for 10 grams of coffee you will only use 100 ml water. You would also want to reduce brewing time, for example, to 2:20 minutes. Make sure that you preheat your coffee maker with boiling water before brewing! Otherwise, given a smaller amount of water, you will end up brewing at a low temperature. Remembering our basic coffee brewing formula, with a 1:10 ratio you will extract more oils, acids and some (or most) of the sugars.

This kind of coffee will not be bitter, because the brewing time is relatively short. It will be aromatic and flavorful, because of lots of oils. Also, it will have an increase in bright acidity because of the higher acids concentration. It will have a good body because of its higher proportion of soluble and suspended solids. At the same time, this coffee won’t be sour, due to a sufficient amount of extracted sugars. This brew will have an amplified but balanced taste and flavor. Make sure you use a low TDS water, as described above.

Change the Brewing Method

Try a different brewing method, for example, Aeropress, or Pour-over. Different beans respond differently to the chosen brewing methods. Light roasts, for example, may benefit the Turkish coffee method. This method suggests using a very fine grind and brewing in an open pot until the foam begins to rise. Light roasts usually lack a strong coffee flavor and this method will ensure a complete extraction.

Try Starbucks blond roast for a Turkish coffee brew. Use the finest grind and a coffee to water ratio in the range 1:10 to 1:17. All these ratios will work well, however, ratio of 1:17 will give a gentler and smoother taste. The body and aroma will be present, as well as body and acidity. Overall, Turkish coffee is the easiest kind of brew for a beginner. This is the only method in which a blade grinder will do because you are going to grind very finely anyway.