Dry-hopping 101

If these words conjure up images of us tipping verdant hop cones from a hessian sack into casks then think again; this is 2014 people!

Here's how we do it - in the conditioning room the tanks are first washed and sterilised before being flushed with Carbon Dioxode to prevent oxidisation of the beer (this imparts cardboardy flavours in case you were wondering...) before being filled with "green beer" - beer which has just finished fermentation and requires further time to mellow and take up hop flavours - then dosed with carefully-measured amounts of T90 hop pellets.  

Pellets are best for dry hopping as the way they are made mashes up the lupulin and makes the aromas / flavours easier and quicker to extract in the tank; 7 days is generally enough although we often allow more.  The other reason we use them is that we can't get whole cone hops out of the tanks after use, meaning T90 pellets are the only option - luckily for us they're our preferred method!

Observe the precision equipment used - yes, that is a Homebase funnel with most of the spout hacksawed off!  Works a treat... 2.5kg of dry hops per 650 litre tank is our current rate, we get two full tanks per brew.

After a week (or more) we begin to drain off the green sludge of pellets from the tanks; this is done 3 or 4 times, tipping beer down the drain on each occasion, until we're happy most pellet debris has gone.  We then connect up the CO2 line to push the beer out of the tank (and to stop oxygen getting in and oxidising the beer) and the racking hose before filling casks or kegs.

The T90 pellets come to us in 5kg foil bags which we try to use all at once in a brew, although some beers have a more complex dry-hopping charge (maybe 2kg Citra, 3kg Cascade) so any pellets not used are sealed up in the bag and stored in our "hop fridge" until required... which isn't usually long.

So there you go, that's our dry-hopping method!  Fascinating, eh?