Saturday, March 4, 2023

Choosing the Right-Sized Coffee Roaster - Mar 4th 2023

Choosing the Right-Sized Coffee Roaster

BH Unlimited Update, Mar 4th 2023

There are roasting machines on the market that will get through 500 kg in a single batch. That's seven coffee sacks in one go. Then there are machines that will do 50 grams per batch. Not even enough for three double shots. So how do you navigate the choice? How does thermal mass affect your roast profiles?

Roasting machines vary hugely in size, from industrial machines such as the Probat PX120 (left) with a capacity of 120 kilograms, to table top roasters such as this 1-kilogram model (right), designed for use in cupping labs.

Starting from the basis that it requires ~11,500 kJ/hour to roast 1kg of coffee, this week Scott Rao gives you a formula to calculate your 'effective roasting capacity' on your roasting machine.

Scott walks us through the metrics involved in choosing the right size of machine. If you're planning to start a roastery and have an idea of the amount of coffee you need to roast each week to break even, Scott suggests the right size machine you would need to be able to roast that amount of coffee in no more than 25 hours per week.

Terroir - New Book Release

If you haven't had a chance to check out our new book Terroir, there's a great preview on our sales page here. If you wanna grab a copy, here are the links you need:
Order: Australia
Order: Global Shop
Order: USA & Europe

If you are up for stocking Terroir in your cafe or training centre, just head here to order a carton of 18 books at a 33% discount with $80 flat-rate UPS express to anywhere in the world. And for bulk wholesale orders, please email orders@baristahustletools.com.

Roasting Science

Have you ever wondered why temperature readings vary so much between roasters, even for similar roast styles? In this week's lessons, we discuss how the thickness and placement of the probes in your roaster affects their temperature readings.

To ensure the bean temperature probe is positioned low enough to be fully immersed in the bean pile, it is often installed in the roaster door.

Following on from Scott's advice about choosing the right size of roaster, we also take a closer look at what limits the amount of coffee you can roast in a given machine. As Scott says, the burner capacity is the most important factor. It's possible to increase the capacity of some roasters by upgrading the burners, and we know of at least one specialty roaster that did this for many years. There's a limit, though — other factors such as the drum volume and the air to bean ratio also restrict the capacity of a roaster.

Ask Martin Hudak Anything

Do you know how to make an espresso martini, an Irish coffee, and a coffee negroni? If you're a coffee person from Slovakia — like Martin Hudak — then the answer will of course be "yes". But if you're feeling a bit unsure about whether you should be using a whisky aged in a sherry butt or a madeira drum,
… should it be white sugar, brown sugar, or honey in the Irish coffee?
… should you use a natural or a washed?
… what TDS% is best to brew at for coffee cocktails?
… how do you get the cream to float? etc. …
We've lined up the world's preeminent coffee mixologist, Martin Hudak, for an AMA.

If you have a BH Unlimited education subscription and a question you're dying to ask, then please drop Martin a line here. You've got until next Friday to get your Qs in.

Quick links

Speaking of books, have you checked out Martin Hudak's new book about the history of coffee cocktails?

After 19 years, the Specialty Coffee Association is beta testing a new cupping form. Peter Guiliano unpacks a lot of this in his lecture here. They have drafted up a two-pronged approach to cupping where they separate descriptive analysis (that's the sort of tests that the Kansas State University used in helping to develop the sensory lexicon for coffee) from affective testing (where you rank your liking for something).

Some of the reasoning behind separating affective and descriptive testing has its roots in research from Sidel et al, 1981. That paper is free to read online.

Speaking of sensory science, here's a nice interview with Ida Steen.

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.