Hops! The magical flower that adds a huge variety of tastes and smells to beer. Without hops, beer just wouldn’t be beer. Hops not only add bitterness to beer, but they act as a preservative, add aroma, taste, and just basically balance out the whole the beverage.
This page briefly discusses the different different compounds in hops then goes through when in the boil hops are usually added. Basically it’s hops tips and tricks! If you’ve stumbled on this page to find out about bittering, our IBU calculator is probably the way to go. If you’re more after descriptions of different kinds of hops, our monthly hop profiles is where you need to be.
The Different Compounds in Hops
Hops have three main compounds that contribute to the different flavours and tastes a brewer will get out of a particular variety of hop:
- Alpha Acids – alpha acids are what’s most commonly referred to when discussing hops. Alpha acids are responsible for the majority of the bitterness a hop imparts on beer. When hops are boiled, the alpha acids are isomerised (turned into) iso-alpha acids, which is what causes a beer to taste bitter. Iso-alpha acids also have anti-bacterial properties as an added benefit!
- Beta Acids – are present in hops but less desirable as the type of bitterness that they impart isn’t palatable. Adding to this, beta acids are more sensitive to decomposing when exposed to oxygen, which add further poor tastes to a beer. Good thing they’re less soluble in water so may just settle out.
- Essential Oils – give all the other wonderful flavours and smells in hops. Essential oils typically evaporate easily, which means they’re able to escape the beer and contribute to its aroma. Those that don’t escape stay in the beer and add to its taste. It’s the essential oils that impart the fruits, florals, spice, and resin (and everything in between) smells and tastes in a beer.
Hop Additions and Timing
Since the acids don’t bring out their bitter goodness without a boil and the essential oils evaporate easily, the timing of hop additions are extremely important. Depending on when hops are added, different aspects of a hops are imparted on a beer.
The longer a hop is boiled, the more of the alpha acids will come out, adding more bitterness to a beer. If hops are added later in the boil (or after the wort has chilled), more aroma and taste aspects of the hop will come out. Boils can last for up to 90 minutes, but some brewers have been known to go longer. Typically, though, 60 minutes is a good starting point for total boil time.
There are five main types of hop additions.
First Wort Hopping
First wort hopping is adding hops as the wort is coming out of the mash tun. This means that the hops are allowed to steep in hot wort prior to and as it’s brought boil and then, of course, are in the wort for the entire length of the boil.
Typically lower alpha hops are used for first wort hopping. But if it’s a higher alpha acid hop, keep in mind that the extra time in hot wort may amount to an overly bitter beer. First wort hopping allows usually insoluble oils to oxidise and stay in the wort during the boiling process. This is because the boiling wort usually causes the essential oils to evaporate, but the steeping at lower temperatures helps prevent this.
Adding to this, first wort hopping can often lead to a more uniform bitterness profile with a more refined and balanced hop aroma.
As the name implies, bittering hops are used to add bitterness to a beer. Having a hop in the boil for at least 45 minutes allows the alpha acids to isomerise and make a beer nice and bitter. During this time, pretty much all of the essential oils in the hop will boil away, so a bittering hop addition will add little to no taste or aroma.
Because of all of this, a bittering hop is one high in alpha acids. No sense in selecting a bittering hop if it’s not full of what you want!
Also referred to as flavour hops, this addition is thrown into the wort for about 20-40 minutes. This allows for some alpha acid conversion while also allowing for some of the essential oils to stay in the wort without evaporating.
Hops of varying alpha acids are often used for taste additions and a lot of brewers with mix a few different hops together to get a few different flavours in their beer. This is a place to experiment and have some fun.
Also called finishing hops, these are added in the last 15 minutes of a boil or at flame out/knock out (when the heat source is turned off). Since the aroma edition hops are only exposed to boiling wort for a short amount of time, fewer oils evaporate out of the wort and are allowed to stay in what will eventually become your beer.
Once again, a variety of hops may be used for aroma, or just a single type of hop, depending on what the brewer is going for.
Dry hopping occurs after the initial fermentation of a beer is finished. The beer may still be fermenting a little bit, but the bubbles created from too vigorous fermentation can allow a lot the aroma to be evaporated off. After all, dry hopping is a great way to put further aroma into a beer and it’s a pretty standard practice for big, hoppy beers.
Hops that are put in as a dry addition usually need a couple weeks in the fermenter to really get themselves into the beer and can benefit from increased conditioning.
A lot of the beers in our home brew recipes section only have a few hop additions, but it’s not unheard of for brewers to do many hop additions and even play with continuous hopping; that is, just continually adding hops over a period of time.
A difference of a few minutes can radically change how a hop performs in a beer, so there’s no reason not to tweak things by a few minutes, split an addition and space it out by 10 minutes or so, or have a variety of additions at different times. That’s half the fun of brewing, and it’s hard to know what the finished product is going to be until you try it.
So go ahead and experiment with hops. Discover new hops and see how they taste. Enjoy your brewing.