Who Moved My Fruit?
If you feel you’ve added enough fruit and let it sit long enough in the fermenter, then it may be the type of yeast you choose that’s to blame in the case of the disappearing fruit. To better illustrate what I mean, here’s a short story from the archives of my brewing journal:
Once upon a time, I wanted to brew a mango fruit beer. I like mangos, they’re not as commonplace in the commercial landscape of fruit beers as say apricots and peaches are, and a mango beer just sounds too legit to quit. So I started with a pretty solid wheat beer base recipe, and took what I thought at the time was some good advice and used a “clean” California Ale Yeast to ferment my fruit beer. This particular California Ale Yeast claimed to have an attenuation rate of 73-80% (although I suspect it was at least 80%), and was also described as being “highly alcohol tolerant”. [That was the foreshadowing part of the story.]
After my wheat beer finished fermenting, I added my mango puree to the secondary and let it ferment out. I took a taste sample. Even though I knew mango can be a relatively mild fruit, I could hardly taste any of the mango’s delicious, unique fruit character, let alone any of that fructosey sweetness you’d expect from a freshly sliced mango. Liquid disappointment.
My knee jerk reaction was to add more fruit. So I did. I pureed a few more pounds of mango, and let it ferment. After fermentation wrapped up (again), I took another taste test. BARELY any additional mango character and still lacking that fruity sweetness you’d expect. I did, however, notice that the beer took on a distinct white wine character, and the alcohol presence had increased somewhat too; neither qualities I was really hoping for. Woo-hoo.
By this point, I’m pretty sure you can guess what happened: básicamente, the California Ale Yeast devoured all of the fruit sugar, taking the mango fruit character along with it, and left me with a dry, winey wheat beer with a bit too much alcohol. Thanks California Ale Yeast- you cream bag.
What’s the ethic of the story? Well, if your goal is to retain a bit more of that fruit character and corresponding sweetness, try using a less attenuative yeast like American Hefeweizen Ale Yeast, European Ale Yeast, or English Ale Yeast. Stay away from California Ale Yeast, Dry English Ale Yeast, or anything much above a 70% attenuation rate, or any yeast that’s listed as having a high alcohol tolerance. It’s OK to use a “clean” yeast, meaning that it won’t contribute much of its own particularly strong or incompatible yeast character to the beer, but don’t sacrifice “clean” at the risk of using a more attenuative yeast.
In case I haven’t stressed it enough, choosing the right yeast for your fruit beer is absolutely, fundamentally, 100% critical when brewing a successful fruit beer, so choose wisely. But even with the right yeast, you might not be out of the woods just yet, especially if you’re bottling.