You may be aware that I’ve lately added some infused gins to my wares at the brewery sales shelf. These are made by Paul Savage, a Wolverhampton local, at Fruit Booze Collective. He mostly uses damsons from his father’s tree and prides himself in wildcrafting the fruits he uses in the infusions. They come in 250mL bottles and are £9 each. I’ve tasted a few and they are delicious!
Paul keeps offering me his spent ginny damsons and sloes from his gin infusions. It’s so tempting. I love fruit and real fruit beers – not the ones made with extracts or flavorings. But there are many problems with fruit.
Fruit can be a source of infection. After all, it’s got wild yeast growing all over it. You have a few choices to deal with this problem, each with its down side:
- Boil it. This will kill the more delicate aromas and usually activate pectin, to create an extra cloudy beer.
- Pasteurize it. Add it to the wort when it’s cool enough to not activate the pectin formation but still hot enough to kill yeast. The problem with this is that, as a brewer, you want to cool the wort as quickly as possible for a better beer. And it takes hours to wait for the wort to cool below 76ºC.
- Freeze it. This really only slows down microorganisms and doesn’t keep them from re-activating once thawing.
- Steep them in vodka (or gin) for at least 20 minutes. This will thoroughly kill microorganisms, but most of the flavor from the fruit will remain in the vodka. So what’s happening is you’re really making an extract and then you want to add the vodka extract to the beer, not the flavorless, vodka-bloated fruit. This does work, but then calculating the corrected ABV after all this takes a little effort.
- Purchase a pasteurized puree of the fruit in an aseptic container. This is my favorite option. There’s no wild yeast in the fruit and it’s almost like using fresh. This would be added to the secondary fermentation stage. The only downside is calculating the actual final ABV.
With Paul’s damsons and sloes, that had been soaking in gin, I would be going with option #4.
The first time we did this, it was for a small 20-liter test batch of a pale ale. He brought over a few kilos of spent damsons from his gin infusions and I kept them refrigerated for a couple of weeks before I was able to use them. I added them to a beer in a secondary fermentor. The final beer suffered from a wild yeast infection. Still drinkable but had that phenolic “Belgian” touch, which shouldn’t have been there. Also, the lovely damson aroma completely faded after 2 weeks.
For this IPA, I decided to not take any chances. I made Paul get up early, drain the fruit, and bring it directly to me. We transferred them to freezer bags. I crushed the fruit in the bags with my hands and put them in the freezer. The idea was to slow down any unwanted organisms before they could multiply but also to freeze cells walls and cause them to burst, making the remaining flavor in the fruit more accessible. When the IPA I brewed had finished fermenting, I dry hopped it with Vic Secret hops. I left those for about a week and then I transferred the beer to another fermentor, thawed the fruit, and added it to the beer. There was still a lot of flavor in those damsons (not so much the sloes). They were really tasty and it took a lot of willpower not to snack on them.
After I added them to the beer, there was no change in the density of the liquid. I was taking specific gravity readings all this time, and they remained constant just before I added the fruit, while they were in contact with the beer, and after I removed them. I concluded that there wasn’t any sugar left over, after all; that’s what the readings indicated. But the beer had a delightful damson aroma, and that’s all I cared about.
Now the bottled beer is done conditioning and I can’t detect any trace of damson or sloe in it. It’s got a great fruity hop aroma, though. It’s a nice IPA but the fruit just got lost in it. Not enough, I guess.
Just as well. Because another problematic aspect of using any fruit in beer is long-term carbonation changes. All fruit has complex sugars that the yeast in the beer will eventually ferment. It just takes the yeast longer to metabolize them than simple sugars. As a general rule, I undercarbonate the beer by 30% to accommodate the extra fermentation. The result is that the bottle won’t gush after the beer has fully matured and the complex fruit sugars have been fermented. But on the other hand, the beer can be a little on the flat side while it’s still young. The results are unpredictable because, unless you use fruit puree – which comes analyzed and gives you a good idea of how much simple sugar is in there – you’re still guessing with the complex sugars and totally wild guessing on the sugar content. So getting the carbonation right is next to impossible, I find.
For this reason and others, I hate working with fruit.
The complex sugars in the damsons and sloes might have been completely extracted by the gin in which Paul had them soaking. If not, they might surprise us all, creating a champagne effect in this batch of beer. I kind of doubt it, though. Being an experienced infuser of fruit in vodka, I know there’s little of value left in the fruit after the infusion period.
So that’s the story of the damson IPA. Oh, and after all this effort, wild yeast contaminated it. It tasted great for about a week, then the phenolic compounds became detectable.
I read that phenols (compounds responsible for that medicinal “Belgian” flavor) are undetectable by 20% of people. They lack the gene that makes them able to taste it. So if you’re one of those people, this beer will taste fantastic to you!