How to Taste Extraction Level in Coffee
- Very over-extracted coffee will taste astringent (think under ripe banana) and bitter (think black tea).
- Slight over-extracted coffee will simply taste bland and hollow - lacking in origin character and sweetness.
- Very under-extracted coffee will be weak, watery, sour and lacking origin character, sweetness and body. It may also taste vegetal.
- Slightly under-extracted coffee may just have slightly too intense acidity and be a bit 'thin'. (This can be greatly impacted by brewing water as well however!) It could also have a predominately nutty flavour - but this is also affected by origin and roast.
Transcript (Speaker: Adam Marley)
Hey, everyone. Welcome to a Sunday evening special edition of our tips and tricks, that isn't at all because I completely forgot to do one on Friday and only just now remembered. So, our tips and tricks for this week is going to be on helping you work out whether your coffee that you're brewing at home is either over or under-extracted. Our most recent tips and tricks were on choosing the right dose and the right grind, and more than once are referred to if your coffee was over or under-extracted and those things.
Now, if you have a refractometer, you can test these things quite scientifically. But for most of us, we're going to be using taste to determine those things. I've done previous tips and tricks videos on how to get better at tasting coffee, probably worth watching some of those. And my little caveat at the start of this is a lot of it is dependent on the water that you're brewing with. I've also done a video on that. So, scroll through and try and find those videos. I've put headings in those so hopefully you can find them pretty well.
But, yeah. So, our tips and tricks for this week, working out whether or not your coffee is over under-extracted. If we start with over-extracted, because it's a little bit easier. If your coffee is incredibly over-extracted, like well over-extracted, then... I mean, the most obvious sign is going to be quite intense astringency and bitterness. And another way to tell that your coffee is over-extracted is it gets bland. I don't know really how to describe it better than that, but there's no liveliness on the tongue. There's no intensity of flavor. It just "tastes like coffee". So if you're encountering that astringency, bitterness, and the coffee's quite blend, there's a good chance that it's over-extracted.
Now, where it gets more complicated, and this is both for under and over-extraction, where you're close, you're almost at a great extraction, but you're a little bit over-extracted in this situation. My little hack for knowing that maybe I've just slightly pushed the extraction too far in a coffee, is that it might not have an overriding bitterness or astringency, but I will have started to lost the origin character of that coffee. So it'll start to, again, taste "just like coffee".
Now at this point, if it's slightly over-extracted, you will still have probably quite a lot of origin character, but the flavor notes won't be, let's say, popping. You might get a vague fruitiness or a vague chocolatey or nuttiness. But everything is a little bit simple, a little bit mellow, a little bit coffee-like. Now, if you hunt for the bitterness, you might find that there is a little bit more bitterness in there, it's perceptible bitterness.
Most of this has to do with lighter roasted and filtered coffee, but it is all applicable to a darker roast, more developed roasts, and to espresso as well. So if you find that you go, "The flavor notes are saying..." Of if you've brewed the coffee before in another way or a different time and you got really clear strawberries and blueberries, and this time you're getting some faint hints of berries and fruit, but realistically it just tastes like coffee, that's a good sign that you've just slightly over-extracted.
The reason for that, stay tuned to the end. We're going to stick with the system of, we'll keep the useful, the really interesting, useful stuff at the start, and then if you want to get geeky about it, I'll explain the why's at the end of the video. So stick through until the end, and if I forget, and you're curious, throw it in the comments and respond to the comments. So I think I've said this a couple of times and then just forgot to do the why's at the end. So yeah, I'll explain the why for that at the end, but that's a nice little... I use this, I use this daily. If the origin character is not quite there, it's just slightly over-extracted. You want to grind a little bit coarser, just a little bit, or use slightly cooler water or less agitation. I usually use grind as my own thing to change there, my variable.
So, under-extraction is a little bit more difficult because some people favor... I think they quite like under-extraction. under-extraction was very common a couple of years ago to really make origin characteristics pop in a cup, to really get those flavors shine through. And it was really popular to over dose, use a really high dose, but under-extract coffees. What you're going to do when you do that is you extract a lot of the really prominent flavors, but you don't get as much sweetness and complexity and balance. So, some people really like that, and that's all good. Not really for me, but the best way to drink coffee is the way you enjoy drinking it and making it.
But, anyway. So, that aside, under-extraction is going to be most obvious as an intense sourness. And this is where water plays into it because if you have a lot of buffer in your water, then that might balance the acidity. So, another way that I will notice that something might be under-extracted or think something might be under-extracted is if, again, the origin character isn't coming through fantastically and is maybe instead replaced with really grassy or hay-like flavors.
Now, that could also be under-development in the roast, but let's try and keep this video not too long. But say again, it's really useful to have a reference point. You know how a coffee should taste when it's extracted really well. If, for instance, the tasting notes and you can trust the tasting notes, or again, you've had the coffee, say something like strawberries and what you're getting is lemon and hay or peanuts, then there's a good chance that the coffee's just slightly under-extracted. Or actually, aggressively under-extracted, potentially.
If it's very under-extracted and you're using normal brewing ratios, like say 60 grams per liter, then one of the ways you'll know the coffee's very under-extracted is if it's very weak. We've extracted less from the coffee, there's less dissolved solids in the brew. As a result, it's weaker. So if the coffee is very weak and sour and you're using normal brewing ratios, like 60 grams per liter, something like that, then there's a very good chance that the coffee is quite under-extracted. I'd suggest grinding finer.
Now whether or not the coffee is only slightly under-extracted. Well, if it's slightly under-extracted, it's probably still going to taste pretty good. Especially for light roasts, then you're going to get a lot of... I call them the spikier flavors, the really prominent flavors. But, the way you might know that there might be more the coffee can give is if you've got a lot of acidity, and maybe quite a lot of origin character, but you're lacking some body and sweetness, particularly the sweetness. That's going to be a suggestion that the coffee's only just slightly under-extracted, and you could probably grind just a little bit finer.
Hopefully that was useful. It might require calibrating your palette little bit with a coffee. For doing that, I would suggest cupping a coffee. Whenever you buy a coffee, if you really want to nail the dial-in, whether it's espresso or anything else is, I would cup that coffee with a pretty standard water recipe. Not just whatever comes out of your tap. You'd want something which you can calibrate with others. So a pretty standard water recipe, check the water video that I've done, and there's plenty of other resources online for water recipes> And then, 60 grams per liter, and then a pretty normal grind size. You want to calibrate with cupping. If you can taste the coffee with the roaster, make sure to come to our public cuppings, first Monday of every month. Or you can trust their tasting notes, that's another great way to calibrate for a coffee.
Unfortunately, there is no precise way that I can tell you how to do this over IGTV, but hopefully these tips are useful if you already have a pretty good palate for coffee or you're developing that palate. Yeah. Sour and weak, probably a little bit under-extracted. Astringent and bland, lacking origin character, probably over-extracted. If it's under-extracted, grind finer. If it's over-extracted, grind coarser.
That's the useful stuff for the video. For the why, for those of you that are still hanging around after seven minutes, thank you. For the why of if a coffee is only slightly over-extracted you start to lose that origin character, I don't know how scientifically verifiable this is, but from my understanding, what happens is you're still getting the volatile aromatics from the coffee, which might give you flavors like blueberries or hazelnut or rose, whatever it might be.
But what's happening is when you slightly over-extract the coffee, you're going to have more astringency and bitterness, which is going to wash out on your tongue, erase the sweetness and the acidity which should have been there. What's going to happen is, a lot of the origin characters in coffee, particularly light roast coffees, and the coffees that we really enjoy roasting, are going to be fruity. And fruits are both sweet and a little bit sour. If the coffee you're drinking, the beverage you're drinking, is not sour or sweet enough, is instead a little bit bitter and a little bit flat on the palette, your brain is going to notice those volatile aromatics of fruity things, but then go, "Hmm, what we're tasting isn't sour or sweet, so it probably isn't fruit that we're eating right now. I'm going to ignore those chemical compounds in the nose right now and not notice them." Basically your brain redacts those flavors and you don't notice them.
So, yeah. That's a good way to know that you're just slightly over-extracting, is that you've probably got some bitterness and astringency in there, which is not noticeable enough as what it is, but is strong enough for your brain to subconsciously go, "This isn't fruit." And you just ignore those fruity compounds, which are probably there in the cup and you're just going to ignore them, which sucks. But it's a good little way to know that you're slightly over-extracting.
Anyway, that works for me. Hopefully it works for you. If anyone else has got some great tips on how to know if you're over or under-extracting in coffee, then please throw them into the comments. And thanks for watching, we'll see you next time. Bye.