Recipe: Sour Power Flemish Red Ale

A Flemish Red Ale takes almost 12 months to ferment but the results are a sour, complex and funky beer that’s more akin to a red wine than an ale and pairs equally well with food.

Hi brewers,

This my first post in a rather long time. In the past few months I’ve gotten married, been travelling internationally (Italy and Korea) for more than 5 weeks and also been working 50-60 hour weeks. It has been hectic, but a fantastic and life-changing few months. Anyway, back to beer.

Today’s recipe is a very old style of beer that has been drunk by the Northern Belgians for hundreds of years, possibly more and one that is gaining more popularity in the craft beer movement. We’re talking about Flanders Red Ale. The local Flemish ale, also known as the Burgundy of Belgium, it is more wine-like than any other beer style. The Flanders red is more acetic (but never vinegar-like) and the fruity flavors more reminiscent of a red wine than an other Belgian styles such as Oud Bruin. It can also finish very dry, with an apparent attenuation of up to 98%. This high level of attenuation is the result of a mixed fermentation by a combination of yeast and bacteria, primarily Saccaromyces, Lactobacillus, Brettanomyces and Pediococcus. This combination of critters gives Flanders Red Ale its distinctive sourness, as well as a complex fruity bouquet. The reddish color is a product of the malt although an extended, less-than-rolling portion of the boil may help add an attractive Burgundy hue. Aging will also darken the beer. Flanders Red is also one of the few beers in which tannins are not only desirable but necessary. With a very low final gravity and long periods of ageing tannins help to provide both body and structure to the beer, providing it with a fuller mouthfeel and complexity much like red wine.

The recently updated 2015 BJCP guidelines give an the overall impression of the style:

A sour, fruity, red wine-like Belgian-style ale with interesting supportive malt flavors and fruit complexity. The dry finish and tannin completes the mental image of a fine red wine.

Aging barrels at the Rodenbach Brewery in Belgium. Courtesy Wikipedia.


The 2015 BJCP gives the following stats for Flanders Red Ale

Original Gravity: 1.048 – 1.057
Final Gravity: 1.002 – 1.012
ABV: 4.6% – 6.5%
IBUs: 10 – 25
SRM: 10 – 16

Notable commercial examples: : Rodenbach Grand Cru, Rodenbach Klassiek, Cuvée des Jacobins Rouge, Duchesse de Bourgogne, Vichtenaar Flemish Ale

Sour Power Flemish Red Ale

The Flanders Red we’re making today is not completely true to style; instead of flaked maize, we’ve used flaked barley in an attempt to give a little fuller body for a style that can often lack it without the use of additional tannins from barrel-aging. It’s also a little stronger, with fewer IBUs.

This beer is not something that will be ready to drink anytime soon and will take anywhere between 6 – 12 months. Its important that the FV you use for this project is not air permeable, as this will increase the oxidise the beer resulting in unwanted sherry-like flavours. While primary fermentation can be undertaken in a plastic fermentor or bucket, it would be best to transfer to a glass carboy or even a Cornelius keg fitted with an airlock for the longer, secondary fermentation. Due to the presence of Brettonamyces, Pediococci and Lactobacilli the beer may develop a pellicle. Don’t be afraid as this will eventually drop out as the beer nears the final gravity. To get some of those traditional oak flavours, you might consider adding sterilised oak chips, staves or blocks to the FV a few weeks or months before the beer finishes, but be careful not to overdo it – it’d be a terrible loss to over-oak such a long project.

Beer Profile

Batch volume: 20 L
Pre-boil volume: 26 L
Pre-boil gravity: 1.048
OG: 1.063
FG: 1.013
ABV: 6.6%
Bitterness: 6 IBUs
Colour: 16 SRM
Efficiency: 79%


Grains % of Fermentables
1.9 kg Beligan Munich Malt (6°L) 35.40%
1.9 kg Vienna Malt (4°L) 35.40%
660 g CaraHell (11°L) 12.30%
330 g CaraMunich (39°L) 6.20%
320 g Special B (115°L) 6.00%
250 g Flaked Barley 4.70%
Kettle Hops IBUs
10 g East Kent Goldings [4.7 AA] – 60 mins 77.6
1 Packets Wyeast Roselare Blend 3763
Target Water Profile
Ion Target (ppm or mg/L)
Calcium 80
Magnesium 5
Sodium 25
Chloride 75
Sulphate 40
Bicarbonates 100


Mash the grains at 68ºC for 60 minutes with 18 L of water. Fly or batch sparge at 80ºC until you have reached the pre-boil gravity. Don’t worry about sparging too hot, tannins in this case are somewhat desirable and will help add some character to the final beer. Bring the collected wort to boil and wait for the hot break to form. Boil for 60 minutes adding hops just after the hot break drops. After the 60 minute, either cool quickly using a chilling device or hot can into a no-chill cube and let it cool naturally. Aerate and pitch yeast. Ferment at 19ºC for primary fermentation.

After the primary Saccharomyces fermentation has finished, purge a glass carboy or stainless steel Corny keg with CO2 (if available) and rack the beer carefully across, avoiding splashing or aerating the beer. Store carefully in a draft-free spot at around 15ºC – 19ºC for up to a year. The gravity will slowly decrease as the Brett. works away at the complex sugars over many months. Eventually, the gravity will stabilise. Take measurements over several weeks to months to ensure that the FG has been reached.

Note: If you harvest the yeast cake from this beer it will produce a more tart and complex beer next time around.

Carbonation and Storage

Carbonate to from 2 to 2.5 volumes and if bottling store for at least 30 days prior to drinking. Similar to wine, Flanders Red Ale will improve with some aging. Perhaps, use champagne bottles and corks with cages for an authentic-looking product.

This beer is something really special. My advice is to make some nice labels for your bottles and to pull them out at special occasions and give them as gifts to those who will really appreciate them.

Cheers! Or as the Flemish say – Santé!

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