Ali Drew, of Christchurch, asks :-
I plan on growing some hops in my garden next year. Can good beer be made from green hops or is it only made from dried hops?
Ralph Bungard, a biochemist who is owner and brewer of The Three Boys Brewery, responded.
What a great idea to grow your own hops! Although almost all of New Zealand’s commercial hops are grown in the Nelson and Motueka region, there is no good reason you can’t grow good hops in many parts of NZ, although they do like cold winters and warm to hot summers to do their best. I collected a wild plant from the Motueka river bed some years back and it is very vigorous and flowers prolifically in my Christchurch garden. The trick is that only the female flowers of the hop plant are used in beer making and it is important that they remain unfertilised: firstly because any seeds can make beer astringent and secondly the unfertilised female flowers produce a lot more of the oils that are so important in giving beer its bitterness, flavour and aroma. Many modern varieties of hops are hybridised and, with that, they are infertile so the production of seeds is never a problem.
You can use the hops green, straight off the vine, to produce beer. In fact, it is becoming a bit of a trend for some microbrewers to do just that at the end of the hop growing season. The only reason that hops are traditionally supplied as dry flowers is so they will keep in a relatively good condition for use throughout the year when fresh stocks are unavailable. Much in the same way that a farmer would store hay or a chef might use dried herbs when fresh stocks are not available. A good hop supplier will take great care in kiln drying hops and then even storing them chilled, in vacuum packs to keep them in the best condition for brewing throughout the year. We take great care of our stored hops in the brewery; we keep them dry, away from light and in the dark to maintain them in a condition as close to fresh as possible.