The Rao Spin

حركة راو الدورانية

The Rao Spin is a technique in which the barista swirls the filter cone during brewing, to make the خليط القهوة spin. It’s named for Scott Rao, who popularised — but did not invent — the technique.1 It’s thought to increase extraction, reduce channeling and make brews more consistent. But how does it have this effect?

قراءة المزيد
Cascara Banned in Europe

Cascara Banned in Europe

Cascara has been regularly hailed as the next big thing in coffee. Once a rare novelty in speciality coffee, in recent years everyone from Starbucks to Stumptown has jumped on the trend for cascara-infused drinks. In 2018, demand for cascara became so high that the price far outstripped that of coffee itself …

قراءة المزيد
App – Pressure & Flow

App – Pressure & Flow

This app simulates the pressure and flow inside an espresso machine while a shot is running. To view the effects of these changes in real time during a shot, click on ‘Graph’ and then ‘Start’, and the app will simulate an espresso being pulled, showing you how the pressure and flow change as the المقاومة

قراءة المزيد
Commitments to Diversity, Equity, and Inclusion

Commitments to Diversity, Equity, and Inclusion

We have engaged consultants and are devoting concerted time to examine all aspects of our business and to identify areas of improvement. This process of consultation will critically examine our hiring of freelancers and employees, our workplace …

قراءة المزيد
Bench-top Roller Mill?

Bench-top Roller Mill?

Industrial grinders, of the sort used to produce espresso pods or supermarket packs of pre-ground coffee, are more or less exclusively roller mills. The most sophisticated of these grinders can grind coffee without significantly heating the grounds, and in the process produce very narrow …

قراءة المزيد
A Few Minutes of Foam

A Few Minutes of Foam

If you leave a latte for a few minutes on the countertop, sometimes the foam starts to break up — but sometimes it doesn’t. Why? No matter how long you’ve been slinging shots, sometimes a latte will go bubbly after pouring. If you’ve ever had to remake a coffee because it was sat on the counter …

قراءة المزيد
Wheels of Steel

Wheels of Steel

The coffee tasted vibrant and clean, and the salesperson showed me how easy it was to wipe away the residue from inside the portafilter — no more scrubbing away with a Scotch-Brite at the end of every day. The steel was a big selling point: easy to clean, more environmentally friendly …

قراءة المزيد
Aroma and Aftertaste

Aroma and Aftertaste

Aftertaste, in coffee, refers to the tastes and aromas left in the mouth after swallowing. Compared to other drinks, coffee flavours hang around for a long time: the aftertaste of an espresso can last up to 15 minutes (RJ Clarke and OG Vitzthum, 2001). Depending on the coffee, this may or may not be a good thing.

قراءة المزيد
Espresso Headspace

Espresso Headspace

Received wisdom in coffee says that if you put a nickel, or a penny, on top of your القُرص after tamping, and lock the portafilter into the group and remove it again without brewing, you should just be able to see a slight impression in the القُرص from where the coin was pressed into the coffee.

قراءة المزيد
The Coffee Footprint Analyzer

The Coffee Footprint Analyzer

One of our aims in producing this course is to provide the information and tools you need to analyse your own carbon footprint. This will allow you to see which changes will have the biggest impact and help you determine which interventions will be most cost effective. At the core of this …

قراءة المزيد
What is a Life-Cycle Analysis?

What is a Life-Cycle Analysis?

A defining characteristic of an LCA is that it includes the impact of raw materials, production, use, and disposal, simultaneously. For example, a change of material could reduce the CO2 footprint from the manufacturing stage, but result in higher maintenance requirements or shorten the lifespan …

قراءة المزيد
A History of Greenwashing

A History of Greenwashing

I would like to start this course with a short story. A confession of sorts. Come with me, as I go to my local cafe. I have forgotten to bring my KeepCup again, but I see they use compostable takeaway cups, so I don’t feel so bad ordering my coffee. While I’m there, I pick up a box of beans …

قراءة المزيد
Temperature’s Hidden Effect

Temperature’s Hidden Effect

In our most recent instalment of the Advanced Espresso course, we discussed a surprising finding in the scientific literature: that increasing the brew temperature makes espresso shots run more slowly. We set out to test this for ourselves, and discovered that the truth is more subtle …

قراءة المزيد
Coffee Grinder RPM

Coffee Grinder RPM

In the last few years, a small number of grinders have hit the market that boast an adjustable grinding speed. The best known of these are Lynn Weber’s EG-1, Victoria Arduino’s Mythos 2, and most recently Ceado’s Hero E37Z. The marketing material for each of these grinders claims that being able …

قراءة المزيد
Changing Grinder Burrs

Changing Grinder Burrs

If you’re looking at your grinder, asking yourself this question, then it’s probably time to change them. While grinder manufacturers may claim that their التروس can grind hundreds and sometimes thousands of kilos of coffee, the truth is that, after they are seasoned, التروس wear out gradually over time …

قراءة المزيد
Cinnamongate

Cinnamongate

“It tastes exactly like a cinnamon bun. You have to try it.” Coffees often don’t entirely live up to their description, but this was different — a coffee with an instantly recognisable flavour of warm, sweet, cinnamon, like nothing I’d tasted before. I had joined the small crowd queuing up …

قراءة المزيد
Why Do Espresso Shots Run Faster?

Why Do Espresso Shots Run Faster?

Why do espresso shots run faster when I use super fresh coffee? It is a truth universally acknowledged that the gases trapped in fresh coffee create bubbles in espresso, which slows down the flow and reduces extraction. This explains why shots from older coffee run...

قراءة المزيد
If a Coffee Doesn’t Form a Crust In a Cupping…

If a Coffee Doesn’t Form a Crust In a Cupping…

Does this mean it’s underdeveloped? Anyone who’s cupped very light roasted coffee, whether from a Nordic-style roaster, or perhaps from a sample roast, will have experienced this: it sometimes doesn’t form a crust in a cupping. When this happens on the cupping table,...

قراءة المزيد
Sugars in Natural Processing

Sugars in Natural Processing

In natural processing, do sugars travel from the mucilage into the bean? Natural processed coffees are typically sweeter and more full-bodied than washed coffees, and often have distinctive fruity flavours. It seems intuitive that the sweetness, body, and...

قراءة المزيد
Fluidised Beds

Fluidised Beds

In our latest poll on the BH Facebook Group, you asked us to check this out: 'If flow goes in much faster than it comes out, then you have the potential to create a fluidised bed. Where does that leave espresso?' Here's what we found out ... This question follows on...

قراءة المزيد

You have Successfully Subscribed!