Duplex Cupping

Do you find that your cuppings don’t taste as good as your brews, or vice versa? There is absolutely no reason as to why this should be with adequately developed coffee. It may be that your current cupping method favours a specific extraction range & your brews another?

So, brew two cups, each cup aiming at a different extraction range.

This procedure is not so much aimed at selecting coffees for roasting. It is more for gauging what is available from one coffee, at one roast level, (e.g. that bag you have just purchased & want to get a handle on), but benefitting from the consistency & repeatability of low agitation, immersion brewing.

You will need:

• Two identical (or as close to identical as possible) 7oz to 12oz mugs, jugs, beakers, bowls, or heatproof glasses, with saucers/small side plates/watch-glasses, that can be used as lids.

Or, use two small, glass, single-wall French presses (cafetieres). The benefit of the French press is that it comes with a lid for good heat retention, and the spout can be used to pour a cup of the tasting sample, allowing the choice to slurp off of a spoon, to sip as normal from a cup, or both. The thin glass doesn’t need preheating like thick walled cups, bowls & glasses. Start with the plunger assembly removed from the press lid.

• Scales that read to at least 0.1g for dosing the dry coffee & scales that will take the weight of the cup & brew for weighing out the water (1g resolution will do here).
• A kettle to heat the brew water, one with a regular spout will be fine.
• Known good & widely available brew water (e.g. Volvic).
• A grinder switchable between two settings, or two pre-set grinders. One will be set around the range between coarse espresso & fine drip (~400µm) the other set around medium drip grind (~700µm). Median grind size may be determined by sieving.

The procedure:

• We are brewing the first cup (Cup #1) at 52.5g/l, or 19:1, for nineteen minutes. We are then brewing the second cup (Cup #2) at 67g/l, or 15:1, for four minutes & starting to taste Cup #2 at ten minutes.
• Grind your coffee for Cup #1 broadly in the ~400µm coarse espresso/fine drip range. Grind your coffee for Cup #2 at a coarser, ~700µm setting.
• Note which dose is which and use the same amount of brew water for both cups. For example, with a ‘3 cup’ French press I aim for 300g of brew water, so I would have a dose of 15.8g for Cup #1 and 20.0g for Cup #2. Likewise, for 180g of brew water we would be looking for doses of 9.5g and 12.0g respectively.

Fill the kettle with around twice as much water as you will need for the first cup. Start heating your brew water.

Start timer: 0:00 …When the kettle boils, preheat the first cup & lid with the boiling water, discard preheat water & drop the pre-weighed coffee (dosed for 52.5g/l or 19:1) into Cup #1 & tare your scales.

Time: 01:00 – Add the brew water to Cup #1. Stir the cup briefly, once the total brew water weight is added, to ensure no clumps of dry grounds are trapped at the bottom of the cup. Make the stir repeatable, e.g. a single ‘North>South>East>West’, from top to bottom of cup, in 4 strokes? Cover (with a saucer/watch-glass/just the lid, no plunger, if using a French press). We are going to leave Cup #1 for nineteen minutes, undisturbed. Use the excess hot brew water, left in the kettle, to preheat Cup #2.

Time: 05:30 (adjust time to match the kettle boil time for Cup #2 at 7:00 minutes as necessary) – Fill the kettle with twice as much brew water as you will need for Cup #2. Start to heat the brew water for Cup #2.

Time: 07:00 – As the brew water for Cup #2 boils, discard the preheat water, add the coffee dose (67g/l, or 15:1) & tare the scales.

Time: 08:00 – Add the one minute off boil brew water to Cup #2, aiming to wet all grounds with the pour only. Do not agitate, do not cover.

Time: 12:00 – Break & sink the crust, then skim/pour off the scum/oil at the surface layer of Cup #2. If you are using a VST refractometer take your Cup #2 TDS sample now, from 1cm under the surface.

Time: 18:00 – Start tasting Cup #2 as soon as the coffee is cool enough. Use a cupping spoon to taste if you wish, but also feel free to pour, or spoon out, samples into another cup/glass to cool off & taste as you normally would. Taste it both hot & cooled. If using a cup to brew, without decanting: as the coffee sits in contact with the grounds, it will continue to extract, so be sure to keep tasting it over the next few minutes. With a French press, assemble the plunger assembly, but don’t plunge as this will kick up silt – hold the mesh & lid in place & carefully pour through the mesh. Pour in small tasting samples, allowing any silt to settle between pours, if you want to see how the brew develops with time.

Time: 20:00 – Uncover Cup #1, the one that you set steeping nineteen minutes ago. All grounds should now have sunk. Skim, or pour off the scum/oil, 30ml or so should do it. If you are using a VST refractometer, take your sample for a TDS reading now, from 1cm under the surface. Use a cupping spoon to taste if you wish, but also feel free to pour or spoon out samples into another cup/glass to taste as you normally would. If using a French press, as with Cup #2, hold the mesh & lid in place above the brew & carefully pour through the mesh. Start tasting Cup #1. Taste it both hot & cooled.

 

Accross the two cups you should have a range of flavours, Cup #2 will usually be around a typical preference point (around 19% to 21% extraction yield, perhaps rising a little if the brew & grounds are kept in contact with each other). Cup #1 will be about as far as you can extract a declining temperature immersion brew (around 22% to 24% extraction yield). It is very unlikely to be over-extracted, in fact it will likely be sweeter than cup one, but maybe with less acidity.

Between these two cups you should get a good idea of the flavours available from the coffee that you have, at one roast level. Focus on flavour, sweetness, acidity, bitterness…not so much on strength (intensity).

If your brewed coffee/shot tastes like Cup #1, but you’d prefer it to be more like Cup #2, grind coarser, or brew/pull shorter for the next shot. Conversely, if Cup #2 is too sour/bright/acidic, see if grinding finer, or brewing/pulling longer for your shots will get you closer to Cup #1?