Fruit Refermentation

Chad Yakobson - Crooked Stave Artisan Beer Project

Selecting fruit is all bout getting the right fruit for the beer. We look at flavor, aroma, acidity, sugars and ripeness.

Selecting the right beer for the right fruit is very important. Overly sour beers with acidic fruit don't work well. You want a subtle acidity if the fruit is one that leaves a lot of acidity. You have to remember that the sugar ferments and you're left with acidity and flavor from fruit.

We like to work exclusively with whole fruit. We get it in fresh, from growers we know and then add it to the beer right away.  The majority of the time we start with "finished" beer so the acidity is already in there.  Therefore the yeast and bacteria culture is present already when we add the fruit.

Aging times and amounts can vary greatly. You might use 1-2 pounds per gallon of some fruits and 4+ for others. It really depends what you are looking for. People love to cram a ton of fruit into a beer. But that doesn't make it the best beer or the most balanced or complex beer. So showing grace in how you add fruit and how much is important.

Racking the beer off of fruit and using temperature to drop out the fruit is very important. This is what we use our large oak foeders for. We add large amounts of fruit back into our foeders and use them just like a wine maker would making wine. We then have a nice flat bottom to rack the fruit off.

Walt Dickinson - Wicked Weed Brewing

Wicked Weed is producing some of the most fruit forward and balanced beers in the country.  Watch and learn how they source fruit, process that fruit, and then use it to influence the refermentation of their beautiful sour and farmhouse beers.

Jeffrey Stuffings - Jester King Brewery

To start off, we only work with fresh fruit or fresh fruit that has been frozen. We don't use any extracts, concentrates, flavorings or anything of that sort. I think there's no substitute for the real thing. We look for fruit with a lot of aromatics and tartness -- the aromatics for obvious reasons and the tartness because it complements our beer. We sometimes take oak barrels of beer that have nice characteristics, but otherwise lack acidity, and referment them with highly acidic fruit. While we've used out of state fruit before, we also select fruit based on what's available locally. We're not trying to approximate flavors from elsewhere, but rather create something unique to our location. Local fruit helps toward this end. 

With regard to considerations prior to adding fruit, we start out by looking for barrel aged beer that's tasting pretty mature. The beer should be completely attenuated and shouldn't be exhibiting any off flavors like acetic acid. It's ok for this beer not to be the most stellar beer in our barrel program. Our favorite barrels end up getting blended and packaged without fruit refermentation. Since so much of the fermentable sugar is coming from the fruit with our fruit refermentations, and because we're using a high ratio of fruit to beer (2-4 pounds per gallon), the fruit character can overshadow some of the subtle fermentation characteristics. Therefore, we choose barrels that we're happy with, but otherwise have something holding them back from being our favorite. For instance, maybe they lack acidity or the aromatics aren't as vibrant and complex as we'd like. In our case, we're not reintroducing microorganisms when we referment with fruit. The yeast and bacteria in the old, barrel aged beer break down the sugars in the fruit. 

Our process: We make a base beer that we age in neutral oak barrels for 8-14 months. The base beer has an original gravity around 1.038 and has a grist of malted barley, raw wheat, and oats. We boil the wort with a blend of fresh hops and aged hops aiming for about 10-15 IBU in the finished beer. We initially ferment in either a foudre or stainless steel tank, prior to transferring to neutral oak barrels for long term maturation. We then select barrels, rack to a stainless steel tank or foudre filled with fruit, and allow refermentation to occur naturally. We conduct "punch downs" on the fruit to get good flavor and color extraction and to prevent the fruit cap from drying out, which can lead to the growth of acetic acid. After about 4-6 weeks of fruit refermentation, we rack the beer off of the fruit and package it. We sometimes do a second refermentation of the fruit. That is, we referment the fruit with mature, barrel aged beer, rack the beer off of the fruit for packaging, then rack another beer onto the "spent" fruit for another refermentation and/or extraction of fruit flavor and aroma. This yield a beer that's more subtle in terms of fruit flavor and aroma, and allows more of the characteristics of the base beer to shine through.