© 2021, Randy Mosher / Craft Beer & Brewing Magazine
No question, people love IPAs. A prime reason is that they are supreme showcases for the heady aromatics of hops: resin, pine, herbs, citrus, stonefruit, tropical fruit and more. As most of these vocabulary terms describe foods, this suggests a question: If these food flavors are so delicious in IPAs, why don’t we just add them directly? Despite some purists out there, we’ve done exactly that.
Adding “other” things to beer besides the Reinheitsgebot trio of malt, hops and water goes back to the beginning of beer, as brewers used any and every handy thing to add flavor and satisfy local tastes. Fruit was usually added either to spike the alcohol with extra fermentable sugars, or to add a little flavoring with seasonal local fruit. Spices were widespread early on; hops didn’t make it to the brewery until 900 CE. Today, spices are traditional in some Belgian beers, and also a tool of creative craft brewers the world over. Wood can act as a sort of spice, too. Until the end of the 19th century, contact with wood was the norm, because there wasn’t anything else to put beer into.
Adding fruits and seasonings to IPA, however, is new. This market trend started about 2010 with citrus versions. So driven by hop flavors, IPAs offer both challenges and opportunities for creative brewers. But whatever they decide to brew, it has to play nice with the hops. Fortunately the flavor chemistry of hops offers bountiful possibilities.
Hops are one of the most aromatically complex botanicals known, with hundreds of different compounds responsible for their attractive bouquet. They get a lot of their floral, citrus, pine, and herbal aromas from hydrocarbons called terpenoids. Amazingly widespread across the plant kingdom, the ones in hops also occur in a huge range of herbs, spices, florals and fruits—especially citrus. The GoodScents database shows more than 200 natural sources for linalool alone.
Here’s a closer look at a handful of hop aroma compounds:
CHEMICAL > AROMA CHARACTERISTICS > SOURCES
Linalool > Orange/citrus, spice, floral, wood > Bergamot, lavender, coriander, thyme
Geraniol > Sweet floral, citrus, fruity > Rose, citronella, geranium, bay
Beta-Citronellol > Floral, leather, citrus, rosebud > Geranium, citronella, sage, marjoram
Myrcene > Sweet, balsamic, fruity, spicy > Blood orange, juniper, carrot, allspice
Source: GoodScents (a really cool aroma chemical resource)
Each hop variety and location has a specific mix of aroma chemicals, with a pecking order of desirability in today’s marketplace. Geraniol is the classic pungent floral of Cascade and its “C-hop” cousins, and while beloved, the market has moved on. Linalool, with its orangey/coriander character is a little more desirable, while the lemongrass notes of beta citronellol get people excited these days.
Hops, especially the newer tropical- and fruit-forward varieties, are lower in some of the less desirable terpenoids, but also contain small amounts of potent sulfur-containing compounds called thiols, blessed with bright tropical characters: mango, passionfruit, guava, grapefruit, pineapple. These have long, hyphenated names and are usually identified with just their acronyms: 3M4MP (grapefruit), 4MMP (blackcurrant, tropical), 3MH (guava, tropical), 3MHA (muscat, passionfruit).
Citrus-spiked IPAs are the most widespread and popular, as the most logical natural extension of hop flavors. New Belgium had a pretty good hit with their Citradelic (tangerine) as did Ballast Point with their Grapefruit Sculpin. Many breweries are currently brewing with common as well as more exotic citrus such as yuzu and bergamot, both of which share linalool and other terpenoids with hops.
Any beer with specialty ingredients is a challenge. As Elysian Brewing founder Dick Cantwell says, if you overdo things, you’ll end up with “Grandma’s IPA,” that is, a little too much of everything, layered on randomly. Flavors need to be harmonious, properly balanced, and telling one single story. Flavor notes that stick out can be distracting or even disrupting. Like a blue note, it’s OK to have them, but you have to choose carefully. The added ingredients have to partner with the hop flavors already there and nudge them into some new direction, but push too far and you’re out of the style expectations. Also, some hop aromas can mask or fight others. Geraniol-rich Cascade and related varieties can be domineering and may dull down bright fruity or citrusy notes. Like jazz, it’s sometimes the notes you don’t play that matter as much as the ones you do.
Citrus, including lemon and various oranges, mandarins and tangerines are very reliable in terms of delivering their flavor into the finished beer. Sour/bitter/Seville oranges are the classic for Belgian witbiers and other historic styles. Lime and especially grapefruit can sometimes be a little more reticent to show their true character.
Citrus peels can be added to the whirlpool or after fermentation along with the dry-hops, adding aroma and nothing else, with no acidity altering the balance of the beer, and no sugar needing to be fermented out. The zest is preferred, as the white pith can add a harsh, tannic bitterness that can detract. Although historic beers often use dried peel, citrus oils can oxidize into a furniture-polish character, and so fresh or frozen zest is usually a better choice.
Non-citrus fruit IPAs are out there, along with an acidic sub-style typically employing a combination of kettle souring plus the fruit’s natural acidity. Yellow fruits, especially tropical ones, are more harmonious with the hops in IPAs than red ones like cherry or raspberry. like mango, guava and passionfruit are expensive, but are tasty and hop-friendly—no wonder they’re the favorites. Pineapple is delicious, but its subtle flavor demands a lot of purée or juice for a great experience.
One challenge for fruit beers is that the peoples’ fruit experience is based on 100% fruit or juice, while the brewer is trying to recreate that flavor with perhaps 10% juice or purée, which is a tall order. Adding acidity is helpful except with super-sour fruits like passionfruit. No clear line separates IPA from non-IPA, but if you add acidity and lower the bitterness, at some point it loses the balance of an IPA and becomes something different, no matter what you call it. A little sweetness may also be helpful, either via mashing techniques or with added lactose, as is sometimes seen in sour + fruit IPAs. A dab of vanilla can do the same, but it turns the fruit into more of a confection.
Fruit juices, purées and concentrates contain fermentable sugars. They are best added towards the end of fermentation, as residual sugars in packaged beer can cause over-pressurized kegs and exploding cans. Some fruits are notoriously unstable in beer. Peaches and their kin are especially challenging, as their main aroma compound, gamma-decalactone, seems to vanish during even a short fermentation. As a fix, it’s often replaced by a little “top-note” aroma extract, helping achieve a ripe natural flavor that can be challenging with pure, real fruit alone.
Herbs and spices also have a huge overlap with hop aroma chemistry; many can be superbly harmonious in IPAs. Used judiciously, culinary herbs like rosemary and thyme can add subtle aromas without getting into into pizza territory. Juniper would be perfect—except that its resiny aroma compounds are nearly insoluble in beer’s watery, low-alcohol mix. One early herbal IPA success was Elysian Brewing founder Dick Cantwell’s Avatar IPA, which brought together jasmine’s perfumy, grape jelly and wild beast personas while clinging to its IPA-ness.
Spruce tips, although quite hard to source, make great IPAs. Rather than smelling of evergreens, they’re fruity/resiny, perhaps a bit like fresh fig or plum. Alaskan Brewing Co. founder Geoff Larson has long been fascinated with pioneer and native peoples’ use of spruce tips as a spring tonic rich in vitamin C. Alaskan Winter ale was the original, but more recently they added a Spruce Tip IPA.
Coriander isn’t of much use in IPA unless you want to add even more linalool, as the stuff is loaded with it. However, sage, basil, ginger, cardamom, bay, woodruff, lemongrass, grains of paradise and pink peppercorns all have their charms, alone or in combinations with each other or with fruits. Many florals make great seasonings: chamomile brings a little Juicyfruit; orange blossom glows with an ethereal, ripe citrus; heather is fruity and balsamic; hibiscus is tart and softly tannic, but begs a philosophical question: Can it still be an IPA if it’s pink?
Oak chips, when added early in fermentation, can morph into a subtle vanilla character and add an appealing lushness in hazy/juicy styles, with crisp tannins tightening up the finish. Brazilian craft brewers are rightfully fond of woods traditionally used for cachaça (sugarcane rum) aging tanks, like amburana with its complex cinnamon/sassafras character.
In the end, the artful use of “abnormal” ingredients is a great way to expand the delicious universe of IPA possibilities, taking the adventurous drinker where no hop has dared to travel before.