I've just tried the first bottle from a batch of APA I brewed and it has a very distinct (and unpleasant) earthy / peaty flavour. Reminiscent of healthy soil. The beer also finishes with a very sharp acidic bitterness (also unpleasant).
What could have caused this? Is it a process error somewhere? Infection / mishandling? Just a poor recipe?
Is it likely to disappear with age or should I flush the lot?
3kg Light malt extract (syrup)
23L batch, 10L boil
50g Willamette @ 30min
50g Amarillo @ 20 min
15g Amarillo @ 10 min
Hops left in the tub during primary (2 weeks) & cold crashed for a week. Racked into a bottling bucket to keep the crap out of the bottles.
Willamette hops are an earthy variety, IMO. It could also be something in your water. Extract has a certain mineral profile already based on where the extract was made. If your water at home has too much of one mineral that is already well represented it can give you some flavor issues. Rare but it does happen. Another water issue may be chlorine or chloramines in the water. All things to look into, but without tasting the beer myself its hard to pin point it.
Earthy flavours can be caused by mold spores in the area you store your beer. They tend to occur in damp areas where the mold grow within the walls of the area and then passes a chemical through any porous surface into the beer (even some glass)
Next batch you make sanitise the equipment and then sanitise the walls, floors and stands etc where you will be storing and fermenting.
Unpleasant fresh soil as you describe it can be a sign for ethyl fenchol which is a water contamination issue. I don't think Willamette or any hop for the matter should lead to a result how you describe it but that's hard to say without smelling/tasting.
I had this earthy woody taste in my IPAs before I started using Camden tablets to remove chlorine and chloromine so perhaps it it some kind of chlorophenol that causes it? I also taste it in some
commercial IPAs. Another possibility is we are sensitive to cohumulone in hops.