Brewing with Lilikoi

Lilikoi is a variety of passion fruit commonly grown in Hawaii. I've read that it takes its name from Lilikoi Valley in Maui, where it was originally planted. While the more common passion fruit varieties on the mainland look purple and wrinkly on the outside when ripe, Lilikoi turns yellow and doesn't wrinkle (before ripening, lilikoi fruit is green). Its fruit is perfectly round and ranges in size from squash ball to baseball dimensions. The plant itself is an aggressive vine that will totally take over if you don't keep it under firm control; you've got to cut it back harshly every few months--sort of like blackberry in Northern California, though lilikoi has no thorns.



The rind of the lilikoi is inedible, a stiff and durable material that resembles packing foam. You eat the fruit by cutting it in half with a knife and scraping out the inner pulp with a spoon. The pulp is very tart and extremely potent--about the equivalent of lemon juice in its potency, or maybe even beyond that. The seeds can be eaten along with the pulp, but because of how potent the taste of the fruit is, it's rarely eaten in its unadulterated form. Usually lilikoi is used for its juice, which is blended with other juices (a popular drink in Hawaii is POG, made from passion fruit, orange, and guava juice) or used to make jelly.



I wanted to use lilikoi in a beer, and decided to try it in an Amber. I'm hoping that the malty, sweet orientation of the Amber style will balance well with the tartness of the fruit, and I'm hoping that the color shade of the beer will be enhanced by the vivid orange of lilikoi juice. I brewed my last batch of beer, mentioned in my post about brewing in a bag, with lilikoi in mind. I pitched it with a British ale yeast, and let it ferment at 72 degrees Fahrenheit, to encourage the development of fruity esters. And the mash temperature was higher, which will likely result in more body and less fermentable sugars, which fit with an English ale.



One of the lilikoi characteristics I wanted to capture was its delicate aroma--a truly unique scent that's unlike anything else. Because of that, I added the lilikoi juice to secondary, when the yeast is less active and has already consumed most of the fermentable sugar in the wort--I didn't want my lilikoi aroma to be blown away by all the carbon dioxide produced with the yeast's initial feeding frenzy. Also, because of my desire to capture as much lilikoi aroma as possible, I treated the juice with only a very delicate pasteurizing process--raising it to 160 degrees Fahrenheit over the course of 20 minutes--before adding it to the carboy. I would have liked to pitch it in directly, with no pasteurizing at all, but Hawaii's warm, fertile environment is full of potential beer-contaminants, making off-flavors a much greater threat here than they were in my San Francisco-based brewing.



In the end I only added about four ounces of lilikoi to about a five gallon batch of beer, dropping it into the bottom of my secondary fermenter and then racking the beer on top. It may not seem like much, but lilikoi is (like I said before) a very potent, very distinct flavor, and I'd rather add too little than too much. My general approach to adjunct ingredients is to shoot for an effect that will be notable, but not overwhelming. I want the drinker to notice something unusual about the beer, but to have to concentrate in order to decipher what it is.

I'm planning on letting the beer sit in secondary for another two weeks, and then bottling. So it'll be about another month before I know whether four ounces was the right amount.