Choosing and Using Different Forms of Hops
Hops have been the herb of choice to preserve and flavor beer for centuries, but only during the last several decades has there been such a wide variety of hop products available to homebrewers. For the purpose of this article, hop “cones” are the whole female flowers of the hop (Humulus lupulus), which can be dried or fresh (also known as “wet”).
The forms of hops typically available to homebrewers today include fresh wet hop cones (home grown, or from local commercial sources), whole leaf dried hop cones, plugs of compressed dried hops, pellets of pulverized hops extruded into small cylindrical pieces, hop hash of hop lupulin glands typically collected off of pelletizing equipment, and hop extracts of liquid hop resins extracted from hops, such as HopShot® or IsoHop®. Each of these forms of hops have advantages and disadvantages that will determine how and when you may choose to use them in your own homebrewing process.
Advantages, disadvantages
While the main focus of this article is on the forms of hops, it is important to look at the points in the process where hops become part of a batch of brew. For those who may be relatively new to homebrewing beer and the use of hops, the chart below offers a brief summary of some of the ways hops can be used and the terminology associated with those uses.
Wet hops
Wet hops are the least processed form of hops, as they are fresh from the plant. If you grow your own hops or live near someone who does, you may be able to get wet hops to add to your brew. Wet hops may be added at any point in the brewing process just as whole leaf hops might be used. Because wet hops are fresh, they may lend a green, vegetal flavor if used exclusively, or in excess, in a given batch. Fresh hops have a much higher moisture content than dried hops so you will need to use roughly seven times the weight of fresh hops as what would be specified for dried hops in a recipe. Fresh hops rarely include an alpha acid analysis, so using them as first wort hops or in the boil is a bit of a gamble as to the bitterness they will contribute to your beer. If an alpha acid analysis is not available, use the mid-range alpha acid level typically associated with a particular variety of hops when calculating the bitterness contribution. Wet hops can be tossed into the kettle loose, or contained in a cheesecloth or other mesh bag so they can be removed to prevent clogging of valves or tubing used to transfer wort to the fermenter.
The advantage of using wet hops is the ability to capture as much fresh aroma and flavor that is available from the just-picked cones. Using fresh, locally grown hops in your brew also provides you an opportunity to participate in the energy conservation and source-identity advantages currently popular among craft brewers. The disadvantages of using wet hops include availability, increased hop material volume (and corresponding wort loss), and the potential for picking up some vegetal flavor (which is normally considered a flaw in beer flavor). Limit wet hop additions to near the end of the boil, after flame-out/hop bursting to derive the most flavor and aroma from the hops while limiting the vegetal flavors that may occur from the hops being in an extended boil. Wort loss can be minimized by using mesh bags to contain the hops and then hanging the bags above the kettle for sufficient time to let the wort drain before discarding the spent cones.
Whole leaf
Whole leaf hops are hop cones that have been picked from the bine and dried to less than 10% moisture content. This form of hops is readily available from homebrew shops and suppliers, keeps well in a sealed container in the freezer, and almost always includes an alpha acid analysis. Whole leaf hops are typically sold in the US in quantities of an ounce to a pound. They originate from hop producers in a compressed bale weighing approximately 200 pounds (91 kg) and are then broken down into smaller quantities for retail sale, often in vacuum-sealed plastic bags. Whole leaf hops can be added to any point of the brewing process to add bitterness, flavor and aroma to the finished beer.
Advantages of using whole leaf hops are that they are easily stored, weighed, and added at virtually any point in the brewing process loose, or contained in a mesh bag. They are also readily available from homebrew suppliers and include an alpha acid analysis for use in bittering calculations. The disadvantages of using whole leaf hops are similar to wet hops in that they absorb wort or beer and thus result in some loss of the final product. They are also a bit more difficult to weigh due to the volume they can occupy in a container in which they are weighed. The one major disadvantage I have, personally, with whole leaf hops is the amount of space they take up in the freezer.
Plugs
Hop plugs are very similar to whole leaf hops except the dried whole hops are compressed into little puck-like cylinders of one-half to two ounces (14 to 56 g). They were developed as a convenient way to add dry hops to casks of beer prior to serving. Hop plugs can be used the same as whole leaf hops as long as they fit into such devices as a hop back or a Randall (which is a device invented at and sold by Dogfish Head Craft Brewery). Because they are not usually in high demand among homebrewers, hop plugs are not always available from most homebrew retailers, but can be sourced from more specialized hop suppliers. They will typically come with an alpha acid analysis and often a more detailed analysis of essential oils that contribute to the hop’s flavor and aroma.
The advantages of using hop plugs are similar to that of whole leaf hops. Plugs are a bit more convenient to store and use because they are more compact and can be dropped into a cask or brew kettle more easily than loose whole hops. They can be used at every part of the brewing process as long as an allowance is made for them to expand and disintegrate. The major disadvantages of hop plugs is availability and that they are not easily broken into smaller units.
Pellets
Pelleted hops are perhaps the most common and convenient form of hops used by homebrewers. They are compact and so are convenient to store and use. They come with alpha acid analysis and are packaged in vacuum-sealed Mylar or plastic packages, sometimes purged with nitrogen gas to reduce oxidation and preserve freshness. Hop pellets are made by pulverizing whole dried hops and then extruding the resulting material through a die that compresses and casts the pieces into cylindrical pellets of roughly an eighth of an inch (3 mm) in diameter of various short lengths. The sticky resins released from the lupulin glands of the hop cones naturally bind the ground hop material together into the relatively stable pellets.
The main advantages of hop pellets is that they are readily available, keep well in a freezer, take up less storage space than whole hops, include an alpha acid analysis and are easy to measure into any desired amount. Pelleted hops are perhaps the most used by homebrewers because of these benefits. One disadvantage of hop pellets are their slightly lower content of volatile aromatics compared to wet hops or whole leaf hops. This can be compensated for by adding a bit more pelleted hops than a corresponding measure of wet hops or whole leaf hops when they are used at the end of the boil or for dry hopping. Pelleted hops also disintegrate into smaller pieces when added to wort or beer and therefore leave more residue at the bottom of the kettle, carboy, or keg. If pelleted hops are contained in a bag or other container they should not be confined too tightly so they are able to disperse and provide the full contact with wort or beer.
Hop hash
Hop hash consists of hop lupulin glands (the yellow bits found at the base of the hop cone bractioles) that have been broken apart and collect on surfaces of milling equipment used to make hop pellets. The resulting concentrated lupulin powder is much higher in alpha acids and aromatic oils by weight than whole leaf hops or pellets. Because most of the dried hop cone material is gone, hop hash produces a flavor and aroma without the “grassy” flavors associated with using a large amount of wet hops or whole leaf hops in a recipe. Hop hash comes with an alpha acid analysis that must be considered carefully when making bitterness calculations due to the higher concentration of alpha acid typically associated with less processed hop products such as pellets. Hop hash can be substituted for whole leaf hops, plugs, or pellets throughout the brewing process with due consideration given to its potency. It can be used to give beers a tremendous hop flavor and aroma when added post-boil in a given recipe. Start low, with an ounce (28 g), as a late boil addition or as a dry hop as you experiment with hop hash, a little goes a long way!
The advantage to using hop hash is primarily for its concentrated alpha acid and oil content that provides the most hop bang for the amount of storage space needed to keep it on hand. It also leaves less residue behind in kettle or keg than whole leaf or pellet hops. Hop hash also produces less grassy flavors in the finished beer because it contains so little green material from the hop cone itself. Hop hash comes with an alpha acid analysis that is significantly higher than whole hops or hop pellets, and thus must be measured and used judiciously. Disadvantages of hop hash are the limited availability of specific hop varieties and that the material is a bit sticky to measure and handle.
Lupulin powder
Another very new form of hops is a powder that was exclusively developed by YCH Hops from Yakima, Washington, called “lupulin powder.” This hop dust is made with a proprietary process of cooling and milling hops, which extracts resins and oils. It is done at very cold (cryogenic) temperatures, using nitrogen to prevent oxidation. Given how they are made, this form of hops, also known as “Cryo Hops.”
Extracts
Hop extracts are made by stripping alpha and beta acids and aromatic compounds from fresh hops using carbon dioxide to get all the goodness hops can contribute to beer without the leafy material or pulverized hop particles from whole leaf hops or pellets. Variety-specific hop extracts are not currently available to homebrewers, only commercial brewers. The hop extracts that are currently available to homebrewers are a bit less refined and sold as HopShots® which are packaged in 5 mL (0.17 fl. oz.) plastic syringes (minus the needle). One milliliter of the extract produces approximately ten IBUs (international bittering units) of bitterness when boiled for an hour in a 5-gallon (19-L) batch of 1.050 specific gravity (12.4 °Plato) wort. These extracts are best used for bitterness rather than flavor or aroma and are not specific to a particular variety of hop like the commercially available extracts.
The advantage of HopShot® products is that they allow homebrewers to add the bittering power of hops to the boil without the associated hop residues or wort loss associated with hop pellets or whole leaf hops. The disadvantage is that the variety-specific hop extracts that contain all of the attributes of the original whole hop are currently only available to commercial brewers. The HopShot® products do not contribute specific or significant hop flavor or aroma that would be derived from whole hops or hop pellets do, only bitterness. If you are brewing a big beer, such as an IPA or barleywine that requires a great deal of hop bitterness, hop extracts may save you some of the mess and beer loss associated with hop residues. Whole leaf or pellet hops can be added later in the boil to produce hop flavor and aroma for your recipe.
Another type of hop extract available to homebrewers consists solely of hop alpha acids extracted with liquid carbon dioxide, that are then isomerized into their bitter form and so do not need to be boiled to develop bitterness in your beer. This type of pre-isomerized extract can be added to a finished beer that is lacking in bitterness to correct final bitterness at packaging. The product currently available to homebrewers is called IsoHop®, and is sold in one ounce (29.6 mL) bottles that can be stored in a refrigerator. Since this product does not contain essential hops oils, it is only suitable for adjusting bitterness, not flavor or aroma in beer. Follow the manufacturer’s instructions for determining the quantity of IsoHop® extract to add to your beer to achieve the desired bitterness.
The advantage of pre-isomerized hop extract is that it can be added to your wort or beer post-boil and thus allow you to make last minute adjustments to beer bitterness, even right up until packaging. It is easily stored in a refrigerator and convenient to use when needed. The disadvantage of this form of hop extract is that it does not supply any hop flavor or aroma, only bitterness to your beer.
Get hopping
With the wide range of hop products currently (or at least seasonally) available these days ranging from fresh wet hops to pre-isomerized hop extracts, homebrewers have an unprecedented array of options to work with to achieve the desired effect hops can have on their beer.
