<< Home || Coffees || Events || About ||
Subscribe ||
||
The vegetal taste in coffee seems to come from two main sources. Neither of which should be considered desirable.
One is the under ripe coffee cherry that adds a vegetal or herbacious note. You know your stuff when you can pick out the under ripes in a batch of unroasted coffee. The hemp descriptions of Sumatras and coffees like Chiapas come to me as more of a high under ripe percentage than true origin character. Under ripe are dulling so in a good roast, the sweetness is severely diminished by these buggers.
The other source is often a very common roast error known as roasting raw. This grassy astringency doesn't always become evident until the coffee is allowed to rest a few days and settle. Roasting raw is defined in the cup by a grassy smell identical to that of steamed green coffee and a punchy acidity that can turn weaker stomaches. It is often the hollow flavors and strong acidity that make this easy to identify as what we jokingly call 'green'.
Roasting raw is excessively common and can hide other problems in the cup while giving the fleeting impression of sweetness. The joke is that roasting raw can hide the age in a coffee and cover over a lack of character in some less stellar coffees where fixing the profile would make the coffees look decidedly poor. The cup will be initially sweet but eventually become hollow, have quickly fading flavors post roast, prove difficult in consistent brewing as a bag ages, and just unpleasant difficult to control acidity.
Labels: green coffee, roasting
¶ Jaime van Schyndel 2:31 PM
Insightful post as always! I would add a third source to your list. Or rather I would distinguish between "green" and "vegetal."
You are right on about the greeny taste that comes from underripe cherries, and I will trust to your expertise on the question of "rawness" in roasting.
There is also a vegetal taste, allied with the cupping term "peasy", that comes from improper drying techniques, or the storage of green or (especially) parchment coffee in moist conditions. It's a kind of rotten vegetable taste that's distinct from mold problems or ferment problems. This is a defect that arises independently of roasting, though like all qualities it is highly influenced by roast parameters. I know this wasn't what you were talking about in this post, but since you mentioned the term "vegetal," I think it's worthwhile to make this extra distinction.
Keep up the rad coffee love!
THis isn't "donnie"... which is just a random name I used for posting on a blogger blog about the NFL... this is Daniel Humphries! (aka "donnie" the coffee-obsessed football fan)
Roasting raw is terminology Simon Hsieh introduced to us. When he came stateside, he had some very insightful observations about some roasters he sampled in his tour we took to heart. Months later, I am finally able to quantify what he meant.
I had a bag of brasil stored in an open bin that turned peasy then finally paper/peanut so I totally get that. As a natural, I expected it to ferment a bit and turn sourdough bread or soggy toast but...
I guess that's why we are vac sealing/nitrogen flushing everything.
I am sad the other commentary/questions about this post were 'offline'. Thanks for the comments Donnie!
<< Home