I assume this is for your Sasion from last saturday. I am pretty sure that orange peel was one of the addons that was put in at the end of the boil, prior to chilling.
What I have done in the past for a fruit addition, is use pasturized juice. With oranges peels, you should be able to sanitize the orange with a dunk in Idaphor solution without causing any harm.
Using Fruits in Secondary Fermentation
For most fruits, the best time to add them is in secondary fermentation. When added at this time, the fruits are not subjected to heat, their flavors do not end up tasting cooked and their aromas are not lost. The drawback, of course, is that adding fruits in the secondary fermenter runs the risk of contaminating the beer. However, green beer generally has enough alcohol and a pH low enough to discourage the growth of contaminating organisms.
For fresh fruits, remove the stems, leaves and pits or seeds. Wash the fruit thoroughly. If you want, you can use commercial produce-washing products such as Fit, although this isn’t necessary. You should reduce the fruit to small pieces by one of several methods: Mash the fruit with a potato masher, chop it with a food processor or cut it up with a knife. Place the fruit in your secondary fermenter and siphon beer on top of it. It is also important that the fermenter is sealed tightly. If air can get in, microorganisms can grow on the top of the floating fruit. (This is what happened to my ill-fated cherry beer.) It is usually best to use a large bucket — one with some headspace — as a secondary fermenter, as some foaming may occur when the yeast begins working on the fruit sugars.
One way to minimize the risk of contamination from fresh fruits is to take a page from the winemakers’ handbook and sterilize the fruit with sulfur dioxide. Winemakers do not sterilize their “wort” by boiling it. They sterilize their “must” by treating it with SO2 (often in the form of Campden tablets). To sterilize a “mini-must,” mush your fruit into a slurry in a sanitized bucket. Add enough water so that it’s basically a thick liquid. Add one crushed Campden tablet for every gallon of your “mini-must” and let sit, loosely covered, overnight. During this time the SO2 will kill any microorganism in the “mini-must,” then diffuse away. The SO2 also acts as an antioxidant, preventing browning of the fruit. The next day, add the now-sanitized “mini-must” to your fermenter.
Adding fruits during secondary fermentation increases the volume of the brew, but some of this volume is lost when beer is racked from the remaining fruit solids. You can plan for this by making less volume of your base beer, but making it somewhat more concentrated. The degree you need to change your base beer depends, of course, on how much fruit you plan to add. (Alternately, you can choose to simply not worry about it and end up with a couple extra beers in your batch.)
To add concentrates, purées or juices to your secondary fermentation, begin racking the base beer to the secondary fermenter. Slowly pour the fruit into the secondary fermenter as the beer is racked so that the fruit and beer mix well. You may want to stir with a sterilized spoon.
The beer can be left in contact with the fruit for varying amounts of time. One week is long enough to extract most of the fruit flavors, but not prolong the batch interminably. If you want to get the most out of your fruit, let it sit longer. Keep in mind, however, that flavor extraction decreases over time. Letting the fruit sit for two weeks will not give you twice as much fruit flavor as letting it sit for one week.
After secondary fermentation with the fruit, siphon the beer away from the fruit solids into a keg or bottling bucket. You may want to use a sanitized kitchen strainer to remove floating fruit solids before racking. Bottle or keg the beer as you usually do.
