Dry hopping is one of the many ways you can add punch to the flavour of your beer. It gives you hop aroma and flavour without bitterness.
Here I look at some of the ideas and techniques behind it, all illustrated with a recent brew.
A few weeks ago I took part in the International Homebrew Project organised by Fuggled, brewing a Scottish mild ale from the nineteenth century. You can find out more about the beer and brew day here.
The recipe called for dry hop additions.
What is Dry Hopping?
Hops are used in beer for several reasons: to add bitterness, to provide flavour and to increase longevity. Hops are naturally antisceptic and can prolong the life of beer.
Bitterness is extracted from hops during brewing by vigorous boiling. This destroys most of the aroma and flavour so more hops are added at the end of the boil as well. The hop oils left in the beer contribute to the taste of the brew.
During fermentation more of this hop flavour is lost, which is where dry hopping comes in. In order to maintain or boost the hoppy taste, you can add dry hops to the beer during the conditioning phase, after primary fermentation.
You could do this for any beer, but of course it is most suited for styles where a strong hop character is wanted. Because the idea is to maximise taste and aroma, choose hops for their flavours as the alpha-acid content is largely irrelevant.
I’m using Kent Goldings.
Dry Hopping Techniques
As you would expect from home brewing, there are many ways of adding the hops.
Although some brewers put them straight into the primary fermenter, it’s generally agreed that it’s best to wait for the primary fermentation to finish. Otherwise, much of the benefit will be lost for reasons described above.
It’s common for brewers using a secondary fermenter to add the hops when they transfer the beer. However, dry hopping in the primary is also possible.
For my batch of mild I wanted to take the beer off the trub. It’s a relatively strong beer and I’m planning to leave it a while before bottling. I took the opportunity to add the dry hops at this point.
I’m working with one fermenter, so I siphoned the beer to my brew pot while I cleaned the bucket.
After thoroughly sanitising the fermenter with Star San, I added the Kent Goldings.
It’s generally agreed that infection from the hops themselves is a negligible risk.
They are naturally antiseptic and the beer by now contains alcohol which makes it harder for bacteria to take hold.
Then you siphon the beer back in, mixing with the hops as the bucket fills. Be careful not to bubble or splash as exposure to oxygen could damage the beer.
Finally the lid goes back on and the beer’s left alone again.
You may want weigh down the hops so they stay submerged in the beer, increasing the effect of the dry hopping.
How Long To Dry Hop?
The duration of the hopping is dependent on the strength of flavour you want.
India Pale Ale, a beer known for a strong hop profile, originally endured several months of dry hopping.
As most students of brewing lore know, IPA developed so the British could send beer to India without it rotting on route. The preservative hops made this possible.
These days most advice suggests anywhere from 5 days to 2 weeks.
Any longer and there seems to be a widespread fear of grassy flavours, although Brad Smith suggests this is an unlikely problem. Over at Mash Sparge Boil 2 to 4 weeks is recommended [Mash Sparge Boil was a blog that unfortunately is no longer around].
For the brew I’ve illustrated here I left the hops a full four weeks before bottling, and it tasted great.
If in doubt, try the beer after 4 or 5 days and take a view.
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