Tuesday, January 31, 2023

How To Choose the Right Roaster - Jan 31st 2023

How To Choose the Right Roaster

BH Unlimited Update, Jan 31st 2023

In this week's BH Unlimited update for our new How To Roast Coffee course, Scott Rao takes on the biggest conundrum for every new roastery: How to choose the right coffee roaster? We unpack all the differences between different kinds of drum roasters. From directly heated drums, we then move into indirectly heated drum roasters. And then the conversation moves to fluidised bed and spouting bed roasters.

You will learn about the pros and cons of each of these systems and how they all work. In case you're curious, here's a little summary of the pros and cons of a conventional directly heated drum roaster (these are by far the most common designs you will see in a specialty coffee roastery)

Pros
✓ Combines convection and conduction, thereby dramatically increasing the rate of heat transfer
✓ Reliable and long lasting

Cons
✗ Large and heavy machine
✗ Requires more gas than a recirculating air roaster
✗ May cause flavour damage if drum temperatures are not well managed

If you want to check out the real thing, you should know that BH Unlimited subscribers have advanced access to each new lesson as the course progresses. There's a risk-free two-week free trial available if you haven't checked out our subscription yet.

In the next update, we will focus on tuning your roasting machine — everything from finding the optimal RPM and airflow, to ensuring your burners are working safely and efficiently.

Is Wet Tamping the New Wet Grinding?

Every so often you happen to cross an idea so bonkers, you have to try it out.

In our latest blog post, that idea was wet tamping. Not pre-infusion, or spraying the puck, or spritzing beans in the hopper, or any of those sensible ideas. Wet tamping — mixing ground coffee with water, then trying to press the wet slurry into a portafilter.

A layer of cling film is essential for tamping wet coffee

The inspiration for this came via our good friend and mentor, Professor Steven Abbott, who wondered if there was some way to reduce the amount of friction between coffee particles in the puck. The idea was that getting the coffee particles to pack tightly and evenly together might reduce channelling — or at the very least, tell us something about the limits of what's possible in tamping.

If you want to get a powder to pack tightly together, the easiest solution is to add something that helps the particles slide past each other — a plasticiser. Water is quite good at this, so why not try adding water to the coffee before tamping?

Well, we tried it, and — spoiler alert — it went about as well as you might expect; i.e. not good. But we did learn a thing or two along the way about preinfusion, blooming, and why high humidity conditions can cause such problems for baristas. It also gave us the opportunity to look very closely at the structure inside an espresso puck. Check out the post to have a look for yourself.

And what's wet grinding you may ask? That's the barista's equivalent of alchemy. The impossible ideal.

The Coffee Buyer's Guide to Colombia

This week in our Buyer's Guide to Colombia, we continue exploring the incredible range of varieties cultivated by Colombian producers. We start with a close look at the latest hybrid variety, Cenicafé 1, and the future of plant breeding in Colombia. With Cenicafé 1, Colombia's plant breeders are again trying to keep a step ahead of a potential future threat, as they once did with leaf rust. This time, the threat is coffee berry disease (CBD), which is already causing huge losses to coffee crops in East Africa.

Coffee berry disease causes severe crop losses in east Africa

We then look at the more exotic varieties to be found in Colombia — of which there are many. Specialty producers are enthusiastically embracing new varieties and resurrecting old ones, making Colombian coffee more diverse than ever. And time and again, genetic testing reveals that some of the most distinctive and delicious varieties to pop up in Colombia are actually long-lost relatives of Ethiopian landraces. It's no wonder that Colombian varieties like Pink Bourbon and Caturra Chiroso have the sweetness and floral aromas to rival better-known African landraces like Wush Wush and Rume Sudan. Has anyone else noticed how great the 2022 Colombian Pink Bourbons have been in general?

Quick links

Our friends Endri & Tanya at Coffee Insurrection run a very interesting website. It's gradually expanding into quite a huge list of specialty coffee shops around the world. So far they've got a lot of detail for Portugal and Italy (we're kind of amazed how many listings there are in both these countries — it's such a transformation from just a handful of years ago). CI are loosely based in Portugal, just with a lot of coffee-related travel in between. But best of all, they do great interviews with awesome coffee people.

It's always interesting checking in on the average price of a latte. In the UK, it went up £0.33p (11.3%) to £3.25 over the last 12 months.

Coffee Education — Without the Advertising

BH provides a level of detail about coffee production that platforms like Youtube are unable to obtain, because we are a subscription service — our members pay us to produce the best, most detailed information for them, rather than creating videos that get the most views for an advertiser.

At BH we never do ads for other company's products on our website. There's no product placement in any of our courses, newsletters or blog posts. Our only income comes from what you pay for your subscriptions.

When you see machinery or coffee gear mentioned in any of our educational material, or featured in our course videos, we have chosen to use that equipment because we like using it, because we think it's historically significant in the evolution of the espresso machine, or because it shows you something you need to see about modern coffee culture. It's as simple as that.