Adding hops to the fermenter lets you bypass the boil and fermentation so the volatile oils that give beer their wonderful hop aroma won’t be vaporized by heat or expelled by the outgassing during fermentation. In a previous article, I discussed dry hopping. In this article, I’ll discuss making a homemade extract of hop oils and adding it to your beer.
Adding Aroma Extract
An easy way to make an aroma extract is to boil a small volume of wort and then steep some hops in it after you shut off the heat. You can then quickly cool your hop oil extract and add it to your beer. My specific method is to use a French press — the plunger device used to make coffee. Place some hops in a French press and pour the hot wort over them. Let the hops steep for 5 to 15 minutes, then press off the liquid. Cool this liquid and add it to your beer. In this method, oils are extracted in the hot wort, but the vapors are largely trapped in the French press. Since the oils are extracted in hot wort, the character of hop aroma it produces is similar to late kettle hopping or whirlpool hopping — it’s just that the amount of aroma is not subsequently reduced by a vigorous fermentation.
The wort sugars added to the beer are quickly consumed by the yeast. If you’re adding the aroma extract at the same time you prime for bottle or keg conditioning, boil the equivalent amount of malt extract to your priming sugar and have your hop oil extract double as your primer.
Comparison to Dry Hopping
Compared to dry hopping, you don’t lose beer by using this method. You actually gain a small amount of volume. If you plan ahead to do this, you should take that into consideration so that any dilution is compensated for. Also, in contrast with dry hopping, this method does not make your beer hazy.
How Much to Add
The amount of hops you need to get the same intensity of aroma is less than you would add in the whirlpool. Generally, use an amount a little less than you would dry hop with. (And keep in mind that the character of dry hopping is different, so you can combine this technique with dry hopping if you want.)
How to Make and Use a Hop Oil Extract
For a 5.0-gallon (19-L) batch of homebrew, here’s how that might work. Let’s say you’re brewing a pale ale and you have a 1-L French press. (This is a common size.) So, you plan to add a little less than 1 L (~1 qt.) of hop oil extract to your beer in your bottling bucket. Brew your beer as you normally would, but finish with a yield of about 4.75 gallons (18 L). Essentially, your beer would be slightly stronger and more bitter, but a little less than a quart (1 L) low in volume. If your recipe called for 5.0 oz. (140 g) of priming sugar, convert this to dried malt extract by dividing by 0.75 to account for the fact that malt extract is less fermentable than straight sugar. (This is 6.6 oz. or 190 g). A small amount of sugar is going to be lost to the hops, so perhaps add 5% to your priming amount.
Bring a little over 1 qt. (1 L) of water to a boil, boil it for 10 minutes (to reduce the oxygen content), then shut off the heat and stir in the malt extract. Add the hops to your French press. If you’re making a pale ale, try 0.50 oz. (14 g) of hops. For an IPA, try 1.0 oz. (28 g) and for a double IPA, try 1.5 oz. (43 g). Pour the wort into your French press with as little splashing as possible.
Let the hops steep in the press for 5–15 minutes. — about the same amount of time you would let them steep in a whirlpool. Then, press off the liquid, let it cool a bit and add it to your bottling bucket. Siphon your beer into the aroma extract (which also serves as your priming sugar) and proceed with bottling as you normally would.
I’ve described this method before and called it French press hopping, but that’s not a good name — you could dunk bagged hops in hot wort, then remove the bag to make the hop oil extract. The French press is just how I separate the hop solids from the liquid. Unless I can think of a better name — aroma bombing? hop juicing? — think I’ll just call it adding aroma extract.
Dry hopping and adding an aroma extract to fermented beer are two ways to boost your hop aroma. The character of these differ slightly, so they can be combined to make a beer with a very intense hop aroma, if that is desired.