Zest Method: Tossing Fruit Peel into the Batch

From throwing whole grapefruits into the boil to steeping the rind in the brite tank, the grapefruit-infused IPA on our Second Profession tap list has undergone many incarnations. This is a recipe that I’ve tinkered with meticulously since my homebrewing days, figuring out how to add fruit naturally to beer to provide balance, which has given us the latest version, the Zest Friends Forever Grapefruit IPA.

When you are adding any adjunct to a beer, there are many ways that you can go about it with varying results. Originally, I had done it in the boil with varying success. In my first attempt five years ago, I threw entire grapefruits (rind, peel, fruit, and all) into the boil at 30 minutes, which resulted in a punishingly bitter beer. On my second attempt, I just used the fruit during flameout in the boil (where you turn the heat off and simply let it sit). This time I ended up with a very “juicy” beer well before it became a worldwide craze. But I was going for a west coast IPA, shooting for a balance of fruit and hops. I was searching for another way to incorporate that bitter, fruity grapefruit flavor and for the most recent version of this beer, I took a new approach that would hopefully provide that balance.

This time around, I opted to add just the grapefruit peel (zest) to the beer on the cold side of the process. To start, I peeled fifteen pounds of grapefruit which yielded about 1.25 pounds of peel, a slight disparity. My goal was to toss the peel after fermenting and cold crashing, so I gave the grapefruit peel a quick vodka bath by dipping it a few times to kill off the wild yeast that grows on fruit. You can use any flavorless ethanol 40 proof or more, but cheap vodka is a good solution (think HRD or McCormicks). Goes without saying: cleanliness is key.

After the bath, I transferred the peel into a sanitized mesh bag with a sanitized weight and threw the peels in the brite tank. I hung the bag inside the tank and anchored it outside by using dental floss. Dental floss is the perfect item to use for this method since it is flat, easy to sanitize, and will allow a better seal on the tank. Fishing wire, while also an okay option, is round, which can lead to potential leaks and therefore contamination. This “zest method” is much farther down the brewing process than what I’d done in my homebrewing days of tossing grapefruit into the boil.

Over the next 48 hours, I constantly monitored how the flavor was progressing to ensure that we didn’t tread into that zone of punishing bitterness I was familiar with. When the flavor was bold but balanced, we carbonated it and put it into kegs. We carbonated to 2.6 volumes to make sure the pairing hops and peel were the stars of the show in this beer.

As of now I am very fortunate to have all the tools and toys to fine-tune my brewing. However, this can still be done on a home-brew level by using a corny keg to accomplish the same effect. By anchoring the bag outside the lid and sealing the gasket, you can replicate the zest method on your homebrew budget.

But unlike the commercial brewing setting, you don’t want to carbonate the beer while simultaneously infusing the beer with the grapefruit peel, since the durations of carbonation and “zesting” are different in homebrewing. In a corny keg, you’ll want to pull out your grapefruit well before that week-long carbonation process starts. Otherwise, your beer will be overly zesty and bitter. I don’t have any exact figures on how long to leave it in the beer, but you don’t want to leave it in there for any longer than 48 hours (unless you really want high bitterness).

To hammer in the point, when you are adding anything to your finished beer you want to make sure that you sanitize properly, especially the fruit. If you’re not into the vodka route, no rinse food-grade sanitizers work, and you can pick those up at your local homebrew store. Additionally, as you will need to open the lid of your corny keg to remove the bagged zest, try to purge the keg with carbon dioxide to blanket it and prevent oxidation.

Pitching rates vary, but I would say that when it comes to grapefruit peel, less is more. The zest is full of essential oils that will give your beer the grapefruit flavor. It will add some of its own bitterness to the beer, so keep that in mind when you are making your hop schedule. I created my hop schedule for 50 IBUs knowing that the grapefruit peel would add between 10 to 15 more IBUs to the beer.

Grapefruit is a wonderful flavor in beer, adding its own fruitful bitterness to complement the hops. The zest method proved itself this time around, but there are many ways to infuse fruit throughout the brewing process to make a beer highly flavorful and unique. Come down to the pub for a pint of the Zest Friends Forever Grapefruit IPA and talk shop with us.