Achieving that woody/earthy quality

Look into English and Noble hops.

 

Agreed with VikeMan that the right place to start is with hops. You're in the UK so I don't see any reason to go beyond his suggestions, but for brewers in North America there are U.S.-grown hops that would work too (e.g. Willamette).

That having been said, in the interest of thoroughness, it's worth noting that a lot of people report an earthy character resulting from the use of rye malt (typically used in the 10-20% range). Rye malt should also contribute to the body and head formation/retention of the beer. Important to note that rye malt can also contribute to a stuck mash, so you need a strategy for dealing with that.

And of course there are various wood products that can give a beer a woody quality (oak cubes, oak spirals, etc.). But as stated above, the starting place is the hop bill, and at the outset I wouldn't venture beyond that unless it's called for by the style.

 

Fuggle Fuggle Fuggle.

And I agree with rye, too. Use a ton of it, like 30-50%.

 

Fuggles for earth
We'd taste depends on what tease you want. Oak, maple cherry, hickory, Apple all give wood taste with extras.

 

UK Fuggles for earthy.

Northern Brewer for woody.

 

Try pride of ringwood. I brewed with them a few years ago and remember them being real earthy and woody in a unique way. Also be forewarned it’s about as polarizing as sorachi ace

 

Fuggles.

Fuggles tastes like dirt.

At who came up with the name Fuggles anyway? Sounds like a freakin muppet to me...

 

That would be brave

 

Why Mr. Fuggle did of course.

Historians do argue this though.

 

A tiny amount of peat smoked malt has done the trick for me. Like 1oz for a standard 5 gallon batch.
Lots of rye works well. Fuggles works but depends on the batch. Some years it's more floral than others.

 

I was just having a cup of tea and I realized that tea would be another way to get some earthy character into the beer. If you do a little poking around, you can find plenty of info about brewing beer with tea. Again, definitely not Plan A, but certainly it belongs in the discussion.

 

That's actually a very good suggestion. Tea is an expensive ingredient but you'd only need a little.