Quarlow Roasting Co.
0114 496 0330 Open an account
Coffee beans turning in the drum of an industrial roaster, lit from inside the barrel

Sheffield · roasting Tuesday and Thursday

Coffee roasted to the second, not to a colour chart.

Twelve kilos at a time on a 1972 drum. Every bag carries the sheet it was roasted on — charge, turn, crack, drop — because the minute and three quarters after first crack is the whole difference between a coffee and a burnt one.

£14.50 a 250 g bag

Free UK post over £30 · roast-to-order subscription from £12.90 a bag · first delivery on the next roast day

Order coffee Read the roast log

The signature — sheet 418, Gitwe, 12.0 kg

Scroll is time in the roast.

Ten minutes and twenty-two seconds, charge to drop, drawn from the bean probe. The plate on the left is the bean at that point in the roast. Nothing here runs backwards, because nothing in a roast does.

Coffee at the charge stage of the roast, 0:00 from charge
0:00 Charge 195 °C
Coffee at the turning point stage of the roast, 1:38 from charge
1:38 Turning point 92 °C
Coffee at the drying stage of the roast, 5:30 from charge
5:30 Drying 152 °C
Coffee at the first crack stage of the roast, 8:36 from charge
8:36 First crack 196 °C
Coffee at the development stage of the roast, 9:30 from charge
9:30 Development 201 °C
Coffee at the drop stage of the roast, 10:22 from charge
10:22 Drop 204 °C

Development

The share of the roast that happens after first crack. It is also the grade every photograph on this site carries.

  1. 0:00 · 195 °C

    Charge

    Green in, drum at 195 °C. The bean is colder than the drum and pulls it down.

    Development ratio 0.0 %

  2. 1:38 · 92 °C

    Turning point

    The bean stops cooling the drum and starts taking heat. 1:38 on the sheet.

    Development ratio 0.0 %

  3. 5:30 · 152 °C

    Drying

    Free water leaves. Straw to tan, and nothing about the final colour is decided yet.

    Development ratio 0.0 %

  4. 8:36 · 196 °C

    First crack

    The bean fractures audibly. Development starts here, and so does the grade.

    Development ratio 0.0 %

  5. 9:30 · 201 °C

    Development

    Sugars brown, acids fall. Every second here costs some of what we bought the lot for.

    Development ratio 9.5 %

  6. 10:22 · 204 °C

    Drop

    Out to the tray at 10:22, 204 °C. Development ratio 17.0 %.

    Development ratio 17.0 %

Six photographs of coffee at six real roast levels, each graded by the development ratio elapsed at that point — so the four frames before first crack are graded by a factor of exactly one, and ship untouched. See the null case: batch 000, gas off

On the shelf this week

Six lots, roasted to their own sheet.

Each one has a development ratio we settled on after three or four attempts, and each bag is posted the day it comes off the drum. 250 g, whole bean or ground to your brewer.

Karimikui, Kirinyaga, Kenya — washed process

Karimikui

Kirinyaga, Kenya · washed

blackcurrant · grapefruit pith · cane sugar

£14.50 dev 17.4 % · drop 203 °C

Alaka, Guji, Ethiopia — washed process

Alaka

Guji, Ethiopia · washed

bergamot · white peach · jasmine

£15.60 dev 15.8 % · drop 202 °C

Gitwe, Nyamasheke, Rwanda — natural process

Gitwe

Nyamasheke, Rwanda · natural

strawberry · cocoa nib · black tea

£13.20 dev 17.0 % · drop 204 °C

La Ilusión, Chalatenango, El Salvador — honey process

La Ilusión

Chalatenango, El Salvador · honey

red apple · demerara · almond

£12.40 dev 17.5 % · drop 206 °C

Cerro Azul, Valle del Cauca, Colombia — washed process

Cerro Azul

Valle del Cauca, Colombia · washed

milk chocolate · orange peel · toffee

£11.80 dev 19.3 % · drop 208 °C

Sítio Bela Vista, Mantiqueira, Brazil — natural process

Sítio Bela Vista

Mantiqueira, Brazil · natural

roasted hazelnut · dark chocolate · brown sugar

£10.90 dev 20.6 % · drop 211 °C

See all six and order Or call 0114 496 0330
Stacked hessian sacks of green coffee in a wooden store

Wholesale

Twenty-two cafés, one delivery round, no minimum after the first order.

We roast to your dial-in, not ours. You get the sheet for every batch, a standing slot on Tuesday or Thursday, and a roaster who answers the phone while the drum is running.

1–5 kg a week
£19.40 / kg
6–20 kg
£17.80 / kg
Over 20 kg
£16.20 / kg
Open an account [email protected]

From the journal

All writing

Roasting · 5 min read

Development ratio, and why we print it on the bag

The minute and three quarters after first crack decides most of what you taste. Here is the one number we steer by, what it does to the cup at each end of its range, and how to read it off the sheet in your bag.

Brewing · 6 min read

Rest: why the bag tastes different on day nine

Coffee opened the morning it is roasted tastes flat, gassy and oddly thin. The same bag on day nine tastes like the thing we sold you. Here is what is happening inside the bean, and how long to leave it.