I have an IPA recipe that makes heavy use of Mosaic and El Dorado hops. I think that adding some tropical fruit to the recipe would accentuate the hops quite well. I buy frozen mango a lot and was wondering if this is OK to use. If so, do I need to take any special precautions regarding sanitation? I had originally planned on pureeing it and adding it to secondary. Thoughts?
I use frozen fruit often. While it thaws mash it lightly to break it up, put on the bottom of the secondary and rack on top of it.
This is the best I have found to get the most flavor.
You can add canned fruit. Check the label to make sure it does not contain preservatives. Consider blending it in sanitized blender. Often people add it at the end of the primary fermentation to help prevent the fermentation being too vigorous and making a mess.
Canned fruit is pasteurized. Frozen fruit could contain pathogens that are not killed by freezing.
Many people have added frozen fruit with success. Freezing breaks cell membranes releasing the juice.
You could pasteurize frozen fruit juice. Boiling it will set the pectin leading to cloudy brew but it will taste fine. You can pasteurize below the temperature that sets pectin.
There is a 3rd option that has worked well for me. Process can be found in the book Extreme Brewing by Sam Calagione (dogfish head brewing)
Fruit Rest. Make your fruit addition at 150-170° on your wort chill down and hold temp for 20-30 minutes. This pasteurizes the fruit and allows it to meld with the wort, so it becomes a true fermentable addition to the beer.
I strongly recommend looking at the chart in book as each fruit type has different temps and durations for best results.
I always soak frozen fruit in grain alcohol (e.g. everclear) to sanitize then rack beer onto it for secondary. Frozen fruits have the potential for contamination so sanitizing is important, and alcohol will sanitize without giving off flavors.