If you’ve read some of the previous posts on this blog, you’ll I’m sure be aware that one of the key ingredients of beer is hops. Hops are a perennial climbing vine (a member of the hemp family). The vines grow to 15 – 18 feet tall, and produce cone-shaped green flowers which are harvested in late summer and dried for use in beer-making.
But what is it about adding hops that is beneficial to beer?
- Firstly, hops impart bitterness to beer which counters the sweetness of the malt sugars. Without this bitterness, most beers would be cloyingly sweet and hard to drink in any quantity.
- Secondly, hops impart flavour and aroma to beer. There are many flavours and aromas, and they depend on the hops variety used:
- English: herbal, earthy, fruity
- German: floral, spicy, evergreen
- American: citrus, herbal, spicy
- New Zealand: fruity, citrus, floral
- Finally hops have a very important anti-septic quality that preserves the beer. This, plus the alcohol in the beer, means that beer can be stored for many months without spoiling. This is why in the middle ages everyone drank beer rather than water: water was nearly always infected and unsafe to drink so it was made into beer which was safe to drink and could be stored.
So when are hops added during beer-making? Well the answer to that is actually pretty much any time: during the boil, at the end of the boil, after fermentation, or in the cask.
To extract the bitterness from hops they have to be boiled for at least an hour. The problem with this is that in doing this all the flavour and aroma molecules are driven off. So brewers tend to add hops at several stages during the boil: at the beginning (for bitterness), towards the end (for flavour) and right at the end (for aroma). Adding hops after fermentation or to the cask is referred to as dry hopping, and obviously is done to deliver more of the most delicate flavour and aromas.
This post is getting rather long… I sense your attention drifting… go on, go get yourself a beer and I’ll post some more another day.
Has anyone ever tried to capture and reuse those aromatics that are driven off in the boil? I know brewing has traditionally been an organic, natural process, but in these days of hi-tec and greater understanding of chemistry I'm quite surprised the raw natural ingredient is still used so much, in preference to "hop extract" or whatever.
ReplyDeleteYes, you can get hop extract in home brew stores and I believe some of the massive commercial beers may use it - it has the benefit of being much more repeatable. But in craft brewing it's highly frowned upon. It has to be the natural ingredients, rather than something that has been extracted. I guess it's a bit like smoked haddock - has it been properly smoked, or painted in smoke extract? Which would you prefer?
ReplyDeleteInterestingly, there have been "hop shortages" in recent years. Crops in certain countries fail and some varieties become unavailable. This is a problem for small commercial brewers - what do you do if you can't get a key ingredient that you depend upon for a particular distinctive flavour in one of your beers? Come up with other recipes I suppose!