Previously I have talked about hops as a means of providing bitterness by boiling them to extract the alpha acids present..
So you can add hops at the beginning of the boil to provide bitterness and towards the end to give you a sense of the aroma and flavour of a particular hop, these are called late additions.
As you boil them for less time more of the flavour of the hops are preserved. As well as this brewers can also do something called dry hopping. Even a late addition of hops in the boil will lose some of the aroma of the hops so dry hopping involves putting them in the fermenter. This means none of the aromatic oils are lost in the boil and you can achieve completely different flavour characteristics in your home brew.
A number of notable styles of beer use dry hopping such as IPA’s and Pale Ales but the beauty of brewing your own beer means you can experiment as you wish and incorporate dry hopping in any style you want.
Dry Hopping Techniques
Generally the best time to add hops is during secondary fermentation when the yeast activity has settled down after the initial burst. Depending on your recipe you add around 25 – 50 grams to the fermenting beer for the period of the secondary fermentation, so around 2 – 4 weeks.
Because there is already alcohol and the compounds present in the hops it is not generally necessary to worry about sterilising the hops and of course you don’t want to boil then as this will drive off the aroma that you are trying to attain.
There is also the option of adding a smaller quantity of hops to the keg if you keg your beer rather than bottle it. This works in the same way as adding them during the fermentation process but remember that your kegged beer will be sitting around longer so less hops should be used.
Also you will want to decide whether to add the hops in loose or in a hop bag. The obvious advantages of using a bag will mean you can separate the hops from the beer a whole lot easier once you’re finished. Of course ensure the bag is sanitised before using, I use muslin bags a boil them for a short while.
Generally when you use loose hops pellets are your best option because they fall out of suspension after a few days and allow you to rack beer from above.