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Barista at Home: The Espresso Machine

espresso machine

It’s the concentrated essence of coffee. A pure expression of the flavors locked in the bean. Coffee with its amplifiers turned up to eleven.

We call it espresso.

After one sip of a well-made espresso, one might wonder how such intensity of flavor is even possible. Baristas know that extracting the best flavors from good coffees takes finely ground coffee, the right amount of hot water, and very high brewing pressure.

The modern espresso machine which creates those conditions is the result of over 100 years’ worth of innovation and refinement. Knowing how these machines work helps professional baristas make better espresso. This same understanding can help the Barista at Home choose and use the right espresso machine in their own kitchens.

Brewing under pressure

One hallmark of a well-made espresso is the silky-smooth caramel-colored emulsion of coffee oils, sugars, and carbon dioxide gas called crema. To get it, and the full flavor of an espresso, it takes high brewing water pressure – about 9 bars worth.

Innovators had long used steam and other mechanical means to increase speed and brewing pressure. It wasn’t until after World War II, however, that a spring-and-lever-driven design was able to achieve pressures high enough to produce crema.

Levers and pistons have now mostly been replaced with electric-motor-driven pumps. Lever machines remain a unique option for mobile espresso bars and the adventurous barista at home.

Controlling the brew water

One key feature of a brewed espresso is its diminutive size. A double espresso typically has a volume of 2 ounces or less. Producing that volume consistently requires controlling the water flow through the ground coffee. In most espresso machines, this water flow is started and stopped by pairing the aforementioned electric pump with a solenoid-driven brew valve.

This combination of pump and valve can be operated in a few ways.

The simplest arrangement finds both wired to an on-off switch. This semi-automatic style puts control of the brew water directly at the barista’s fingertips. It’s simplicity usually means lower price. The barista does need to monitor the espresso carefully though: watching the stream of coffee while it brews into a shotglass or familiar ceramic cup, possibly guided by a small scale.

Other machines automate the process a bit more by stopping the shot for the barista. This volumetric system uses a small flowmeter to measure the amount of water dispensed, then stops the flow at the programmed volume. This type of system works reliably but is typically a bit more expensive than semi-automatic versions.

The boiling point

Brewing water isn’t the only thing under pressure in an espresso machine. Most are built around a steam boiler which contains both superheated water and pressurized steam. The steam is useful for steaming milk for various espresso beverages, which we’ll discuss in a future episode of Barista at Home.

To make great espresso, brewing water must be heated to about 200⁰F. One good way to do this heats brewing water by passing it through separate chambers inside the steam boiler called heat exchangers. This popular approach relies on careful design and barista skill to produce appropriately-hot water. It’s mechanically simple, inexpensive, and works well.

Another great approach heats brewing water directly using one or more dedicated coffee boilers. This multiple-boiler style of machine often uses a digital heater control to ensure that brewing water reaches the coffee at exactly the right temperature. This degree of control is appreciated by many baristas. Like many premium features, this control comes with a premium price tag.

A hot shower

Once brewing water is heated, it flows to one or more brew groups. This highly-specialized component serves several important functions.

Since the group is water’s last stop before reaching the ground coffee, the group can fine-tune brewing temperature. Clever Italian engineers have long counted on this, which is why many groups are heavy and made of brass.

Even extraction is essential for espresso quality. For that reason, espresso machine groups use internal channels and stainless steel screens to create a uniform shower of water.

Brew groups also feature pliable gaskets to keep pressurized brewing water contained, as well as grooves which securely hold while still allowing the barista to remove a closely-related component…

The portafilter

As the name suggests, the portafilter is a portable filter. It’s purpose is to hold the ground coffee during the extraction process.

The “filter” portion is a small stainless-steel basket, its bottom perforated by dozens of tiny holes. This basket is held in a sturdy chrome-plated brass housing. Many feature spouts on the bottom to direct streams of brewed espresso into waiting cups. All have a handle to enable the barista to easily remove it to dispose of spent grounds and reload with fresh.

Portafilter baskets come in a variety of sizes. 1 ounce single espressos might utilize a basket designed for as little as 7 grams of ground coffee, while “triple baskets” meant to produce larger volumes may accommodate well over 20 grams. Baskets do have an optimal fill level, so skilled baristas will select a basket which is appropriate for the amount of espresso they plan to make. Most professional baristas choose a “double basket” which is ideal for 16-20 grams of ground coffee and between 1 and 2 ounces of brewed espresso.

Better coffee through science

A well-made espresso: good coffee, finely ground, plus the right amount of hot water, brewed under pressure. 100 years of science has never tasted so good.

Want to learn even more about using science to make better coffee? Stay tuned for next month’s edition of Barista at Home. Can’t wait that long? Call Dilworth Coffee at (866)849-1682 and ask to talk with Brady about Brewology.

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Barista at Home: Coffee Brewing Gear

coffee brewing gear

The gift-giving season is upon us. Need some ideas for your friendly neighborhood coffee geek?

Here’s a hint: home baristas love toys.

Make no mistake, professional baristas can MacGuyver rigs to brew great coffee out of some pretty random household items when needed. Having the right tools can make achieving good coffee easier, more consistent, and much more fun though.

In this second installment of our Barista at Home series, we’ll check out some of our favorite coffee brewing gear. We’ll also pinpoint which brewing essentials these tools use to help you make great coffee at home too.

Turn up the volume with Coffee-to-Water Ratio

A delicious cup of coffee has balance: excellent flavor and enjoyable strength. Strength in this case does not mean a “bold” or bitter flavor, it’s the intensity of the flavor. If coffee were music, strength would be the volume. Our goal is to turn that volume up to create an enjoyable experience without changing the sound, err… flavor quality.

This is pretty straightforward to do: the more ground coffee you use for a given amount of water, the stronger and more concentrated the resulting brew will be. Baristas refer to this recipe as the coffee-to-water ratio.

How strong? Dilworth Coffee recommends using 1 part coffee to 17 parts water (that’s 3.75oz coffee per half gallon, or about 55 grams per liter). With that ratio, and a proper extraction your finished brew should be a crowd-pleasing strength.

How can good coffee brewing gear help?

Most professional baristas count on a scale to weigh out the exact amount of coffee. They’ll also brew on a scale to make sure their water measurements are equally precise.

An accurate kitchen scale works (and is useful for other tasks). That said, I like the built-in timer feature on the Hario v60 Drip Scale. Those looking to splurge might upgrade to the Acai Pearl scale with its Bluetooth functionality.

Fine-tune with Temperature and Turbulence

Unless coldbrew is your thing, you need HOT water for proper brewing. How hot? We recommend 195-205 degree F water for best results. No precision digital thermometer handy? Just bring your water to a boil right before brewing.

While you could boil that water in your microwave, most pros’ coffee brewing gear includes a purpose-built kettle instead.

My go-to electric kettle is from Bonavita. It heats water quickly and features a long pouring spout to help control turbulence (more on that shortly). It’s digital sibling is a nice upgrade, giving you more precise control of the brewing water temperature.

Did I say turbulence? Buckle up, little coffee grounds! For a tasty extraction, we need to keep everything moving and interacting with the water. We describe that movement as turbulence.

The long “gooseneck” spouts on coffee pouring kettles enable the barista to pour with precision. Directing the water so it reaches all of the grounds makes turbulence more uniform.

Those spouts also limit water flow, which helps to control the magnitude of the turbulence. That’s important, since too bumpy of a ride can shake unpleasant flavors loose.

Have some fun with Brewing Devices

Scales and kettles may be useful tools, but brewing devices are where the fun really happens.

Most professional brew bars feature some kind of pourover brewing device, with popular choices including the Hario v60, Kalita Wave, and Beehouse or Bonmac drippers. I’ve enjoyed delicious coffee from all of these, though the Kalita Wave is my go-to method.

What makes the coffee from each of these methods unique? Variations in filter shape are responsible for some of the differences in the cup. Many pro baristas prefer the pointier cone shape of the v60, though flat-bottom or truncated-cone-shaped filters make it easier to consistently brew good coffee.

The number and size of the holes in the bottom of the device also make a difference. This can vary from the single small hole in a Bonmac to the wide-open v60. Like to tinker? Check out the adjustable December Dripper – it’s the hot new brewer of the year and sure to be on your favorite barista’s letter to Santa (hint hint).

No matter which brewer you choose, be sure to select the size that’s appropriate for you. I usually pick the two cup version, which performs equally well whether I’m brewing a single mug for myself or sharing with a friend.

Make your list, check it twice.

Good coffee brewing gear: it’s a good gift idea for the barista at home AND a great way to make better coffee. Want more information on brewing great coffee? Continue with Part 3 of our Barista at Home series, “Start with Good Coffee”. Also check out Dilworth Coffee’s Brewology resources or call Brady at 866 849 1682.

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Barista at Home: Brewing Essentials

brewing essentials

The Holiday Season is upon us. For many of us, that means traveling to visit family and friends. For baristas, chances are good we’ll be waking up early and brewing them coffee once we get there.

What do baristas do differently that makes our coffee taste so good?

Better yet, what can we all do to make better coffee at home too?

Read on, dear friends…

What makes coffee taste so good?

A roasted coffee bean is a treasure chest full of flavorful sugars, aromatics, acids and oils. The goal of brewing is to unlock the best of those flavors and dissolve them into a delicious and drinkable form.

Baristas know that brewing good coffee at home requires good ingredients, the right tools, and an understanding of the brewing essentials.

What are the brewing essentials?

When we brew coffee, we’re putting the process of extraction to work. Water does the heavy lifting. It dissolves flavoring solids, breaking the bigger molecules down, and then helping them diffuse out of the coffee grounds and into our mugs. A good barista fine tunes the flavor of their brew by controlling this extraction.

The coffee bean may be a treasure chest, but not all the flavors inside are treasures. Fortunately, different flavors extract at different rates and less desirable flavors tend to extract more slowly. Our goal is to pull out as many of the tasty flavors as possible before things start to go wrong.

How do we control the extraction to accomplish this?

Seven elements of the brewing process, the brewing essentials, can help us achieve that deliciousness. Today, we’ll consider two important and closely-linked elements: grind setting and brewing time.

The Grind and why it’s so important.

Imagine we’re flavoring solids enjoying a concert at The Grind Auditorium with thousands of our closest friends. As the show finishes, everyone’s nicely dissolved and ready to head to the afterparty. First, though, we need to diffuse our way out of the venue (preferably leaving some of the more obnoxious flavors in the room behind).

Who will make it to the afterparty before the Mug Club reaches capacity?

That depends largely on two factors: our distance to the nearest exit and the time we have to get there. If The Grind has opened an exit in our section, we can exit quickly. If only the more distant main doors are open, though, it will take a while for all of us to make our way outside.

Extraction is similar. The smaller the ground coffee particle, the closer the exits and the faster the extraction occurs. Conversely, the larger the particle, the longer it takes for extraction to happen.

Fortunately, managing grind particle size is easy if you use a high-quality burr grinder.

What about time?

A given particle size has an ideal contact time; the amount of time water is in contact with the ground coffee determines the amount and quality of coffee flavoring solids extracted. Too short for the particle size and you leave flavor behind yielding a sour, underextracted cup. Too long and those unpleasant flavors start to show up, turning our party harsh, bitter, and overextracted.

Understanding these two brewing essentials can help us control the extraction by matching grind setting and brewing time.

While drip brewers do let you control how quickly water is being poured over the coffee grounds, the coffee bed’s resistance determines how quickly that water drains out. This means your total brewing time can’t be directly controlled.

What to do?

An encore at The Grind.

Water drains more quickly through coarser ground coffee and more slowly through finer ground. That means changing grind setting affects the results in two ways: by changing the speed of the extraction process AND influencing the total brew time.

That’s why controlling grind is the easiest and most effective way to fine tune your drip brewing process.

I usually start with the grinder setting recommended by the Dilworth Coffee Brewing Guides, brew a batch, and taste the results. If the coffee tastes bitter and brewing took longer than recommended, I’ll try again with a slightly coarser grind. If it tastes thin and sour and the time was too fast, I’ll use a slightly finer grind.

Let those barista guests sleep in!

With the right combination of grind setting and brewing time, you can manage your extraction like a professional and unlock those tasty flavors for yourself. Just make sure to save them a cup, I hear that show at The Grind went pretty late.

To learn even more about the brewing essentials check out next week’s edition of Barista at Home: Coffee Brewing Gear. Can’t wait that long? Contact Brady Butler at 866-849-1682.