Ask anyone when the best time is to plant a tree, and they’ll give you this answer: “20 years ago – or today.” It’s kind of the same with long-aging sour beers. Some are put off by them because of the time it takes for them to fully ferment and mature (at least six months, and up to two years), but if you get into the habit of brewing them twice a year, you’ll nearly always have a good one on hand! I rotate between my quicker Berliner Weisse and a Flanders Red or Brown.
If you’ve never had a classic Flanders Red Ale, you really don’t know what you’re missing! They’re a real riot of flavors, from rich fruity notes of black currant and plum and berries, to bright acidity and dark funk, and even a raw-grain-and-biscuit malt background. Hops play only a limited role, which isn’t uncommon in sours (for a variety of stylistic and biological reasons), but there’s still more than enough to keep the palate entertained. They are nearly-fully attenuated, and they are also lightly carbonated. And, of course, they are also red.
A lot of beer folk pitch them as being “wine-like,” but I really don’t understand that mentality. What, because of the red fruit flavors? These are beers, with a modest 5-6% ABV range but still a noticeable amount of bitterness, and while they may be thinner and fruitier than other beers I think you’ll have a tough row to hoe if you try to sell these to your wine-loving friends as “wine-like!”
You’ll find quite a range out there in terms of grist for a Flanders Red, and in truth there’s no “go-to” option here the way there is for, for example, lots of the Belgian styles (Pilsner malt time!) or English beers (more Maris Otter!). In considering grist, then, I like to work from what I want to taste and then fit grains to that profile. To ensure a rich, bready malt background I like to start with a 50/50 blend of Munich and Maris Otter, about five pounds of each. Then it’s half a pound each of Aromatic malt, Briess Special Roast, and flaked oats, and a quarter-pound of Special B. You’ll find recipes that drop in wheat here, which is fine, but to me the flavor was always too mild and I’d rather have more of the others! This blend, though, really ramps up the toast and grain complexity while adding a touch of malt-derived dark fruit character.
Hops are easy here: 15 IBUs of anything. If I have Hallertau on hand (I usually do), that’s what I use, but you can also go with any European or English low-alpha hop variety.
Then there’s yeast…and more. I ferment this one with Wyeast 1007 German Ale yeast first, which is generally clean but adds some light red fruit esters (which we want), and then let the Wyeast 3763 Roeselare blend finish it off in secondary. If there’s a criticism here it’s that it’s a little too clean, but if I stick to these two I almost certainly minimize both diacetyl and a strong acetic flavor, both of which are killers. Too much time and effort goes into this one for me to roll the dice.
Finally, you’ll (eventually) need some French Oak cubes, Medium or Medium-plus toast.
A quick word on dregs usage, here: lots of the best examples here are pasteurized, so growing up the yeast you find in the bottles of your favorite Flanders ale will usually not be a viable option.
Do a standard mash and boil here, then ferment as usual with the German Ale yeast at about 65F. Near the end of primary fermentation, increase the temperature to 68-69F to ensure that any diacetyl/precursors are cleaned up (there shouldn’t be much, but better safe than sorry!). At this point, rack into a second (usually glass, to minimize oxidation) vessel and pitch the bug blend. Once I do that, I generally stash these under the stairs in my basement. Temperature control isn’t especially important, so long as there aren’t wild swings or extremes in temperature, and a basement does the trick in most cases. If you don’t have one, any relatively temperature-stable room in the house will do. You might consider a walk-in closet, too – they have little air movement, tend to be interior rooms with no light penetration, and there’s not much off-gassing to make your clothes smell funky (or you might like that).
At this point you can think about adding the oak cubes. When it comes to oaking you have two options: add them at the start of secondary (after a healthy near-boil to kill anything on them), or add them at the end and age on oak, to taste. Honestly, I say just toss them in now, but if you’re sensitive to oak/tannins then you can add later and pull the beer when it hits your sweet spot. Also, which toast level? Some people say that medium-plus is too campfire-ish for the Red ale (but not the Flanders Brown), but I absolutely love the sensory contrast created by the relatively-pale red color in this beer paired with the more-toasty wood character, and it also adds a dry flavor that pairs well with the bright fruit.
Total aging time in secondary is 6-12 months – and probably more towards the “12” end of that range. To say you want a “complete” fermentation is an understatement here. Once you think it’s ready, you can carbonate to about 1.75 volumes of CO2 (and I cheat here, using a dedicated keg that I don’t mind getting all bugged up).
The wait is truly worth it. This recipe should get you off to a great start, but as you refine it for your system and preferences you’ll find that this is one of your best and most-enjoyable beers. Don’t let the long wait put you off. The best time to brew a Flanders Red? A year ago – or today. Make it today.