Sour & Funky | Kettle-soured Brett Saison

As all good beer snobs eventually do, I’ve taken a dive into the world of sour and funk. A deep, deep dive, to a depth of funk I’m unlikely to emerge from anytime soon. It may be pretentious, but my is it glorious!

Learning to brew clean beers has a pleasant feeling of linearity, and with careful attention to process all of us can easily brew examples that drink as well as (or better than) commercial examples. Tasting my Czech Pilsner recently, I was stunned by the fresh malt flavour that I’d only experienced previously with Pilsner Urquell in Prague. This is the power of the homebrewer – complete control of our process, freedom to imitate or experiment, and the great luxury of drinking fresh.

Pilsner anyone?

I’ve been starting to feel comfortable with brewing these cleaner styles, and am now pretty happy that I can pump out a decent pale ale, golden ale, Belgian blonde, Kolsch, and saison with relatively few balls-ups along the way. Darker beers are untamed territory for me at this stage, though I no longer drink a huge number of these, favouring refreshing styles that still lend a good degree of complexity. Having proven to myself that I can safely produce a pilsner without obvious off-flavours, I felt somewhat emboldened to take on the challenge of sour and funk.

The Milk the Funk wiki will change you, man.

There’s no shortage of information on this buggy new world, with the Milk the Funk wiki being an incredible wealth of useful science and anecdotes. Join the MTF Facebook page, and you’ll soon grasp the enormous degree of experimentation that homebrewers are undertaking worldwide. Kviek wine? Leptinis? Raw Brett barley wine? Corn chip saison? What a time to be alive!

Not wanting to go full-blown mixed-fermentation sour initially (read: I’m an impatient bastard) I elected to take on a kettle-sour. I’d recently undertaken my first Brett harvest from a bottle of Garage Project’s excellent ‘Heels to Jesus’ , which was throwing off some excellent fruity, pineapple-y notes and a touch of funk. Having been inspired by Michael Tonsmeire’s excellent article on hoppy sour beers, I figured a kettle-soured hoppy Brett saison would do just fine for my first foray. 

Do yourself a favour and drink this beer. Jesus approves.

I carried out this brew over two days. Saturday morning I mashed in and produced a similar wort to my previous saison, with Vienna replacing Munich (given that’s what I had on hand). Efficiency was higher than expected, with the OG for this brew hitting 1.056. I then boiled the wort for 5 mins, killed the heat, then allowed to cool during the day. It took 10 mL of 88% lactic acid to drop to pH to 4.49, reducing the odds of enteric nasties fouling my beer during kettle-souring. Once the wort  hit 45 °C, I placed a cup of pilsner malt (my source of souring bacteria) in a sanitised mesh bag, and shamelessly threw that into the wort. I then insulated the kettle, placed a lid on to limit oxygen ingress, and left it alone for 24 hours. The next day, the pH had dropped to 3.5, and had a pleasant tart, stewed fruit flavour. Not quite the clean lactic produced by lactobacillus alone, but surprisingly complex. This was going well!

Starting the souring

I then proceeded with a 90 min boil, killing all bacteria in the kettle and hopefully eliminating any DMS contributed by the Pilsner malt. Koppafloc was added at 10 mins, then once I killed the heat I added the flameout hop additions, and began cooling immediately with my immersion chiller. Unfortunately, disaster struck in the form of a leaking hose, spraying unquantified volumes of unsterilised water directly into my wort! After much cussing (the garage was also rather saturated), I hit the heat for a minute, bringing it back to boil to re-sterilise, though rather concerned at how much each bitterness the hops would now be contributing to the beer.

The "Brewery"

Once cooled to 32 °C, the wort was pumped into my plastic carboy, and half of the Brett starter added. The following morning there was a fine white layer of foam which I presume was Brett. I then added a packet of BE-134 and the remainder of the Brett starter. 12 hours later a more familiar tan krausen had formed. The fermenter was then left at ambient temperature for 9 days, after which the CO2 had slowed right down. For a final hoppy touch, I kegged the beer with a hop spider full of my home-grown whole-leaf dried Motueka and Nelson Sauvin. A spunding valve was attached and set to 15 PSI. Once the beer had reached the desired level of funk a week later, I chilled and connected the keg to my kegerator. 

The following morning
12 hours following BE-134 pitch

Sour & Funky Saison
Recipe Specifics
Batch Size (L): 22
Total Grain (kg): 5.13
Anticipated OG: 1.050
Actual OG: 1.056
Actual FG: 1.005
Actual ABV: 6.7%
Anticipated SRM: 5.9
Anticipated IBU: 19.1
Brewhouse Efficiency: 70%
Wort Boil Time:  90 minutes

78.0% 4.00 kg. Gladfield Pilsner Malt (1.9 SRM)
9.70% 0.50 kg. Gladfield Wheat Malt  (2.1 SRM)
9.70% 0.50 kg. Gladfield Vienna Malt (3.3 SRM)
2.50% 0.13 kg. Caramunich III Malt (71 SRM)


30.0 g. Willamette (NZ) (Pellet, 7.40% AA) @ 0 min (10.0 IBU)
50.00 g. Motueka (Pellet, 4.00% AA) @ 0 min (9.0 IBU)
10.00 g. Mixed Motueka and Nelson Sauvin (Whole leaf, dried) @ keg hop (0 IBU)


Fermentis BE-134

Brettanomyces (uncertain strain) harvested from Garage Project ‘Heels to Jesus’

Water Profile (ppm)
Bru ‘n Water ‘Yellow Full’ 

Ca 56 | Mg 11 | Na 6 | SO4 54 | Cl 75

Mash pH 5.32

Mash Schedule
Sacch Rest – 60 min @ 67 °C

Brewed 28/04/19 by myself.

Wort soured to pH 4.49 using 10mL of 88% lactic acid

Brief 5 min boil undertaken , then wort allowed to cool passively to 45 °C over 5 3/4 hours.

One cup of Pilsner malt placed in sanitised mesh bag and placed in wort. 25 hours later pH measuring 3.5, temp remained at 24.5 °C. Smelled like stewed fruit, some funkiness.

Proceeded with 90 min boil, hop additions made at flameout, then cooling hit immediately via immersion chiller + whirlpooling.

Pumped into fermenter once 32 °C, small volume of Brett dregs pitched. Following morning (10 hours later) some activity, white foamy top. My ‘Brett’ starter tasted of banana and fruity funk, hence suspect the bottle dregs contained an abbey yeast as well as Brett.

Packet of BE-134 and remaining Brett dregs pitched at 22.1 °C that morning. Furious CO2 production and high krausen 12 hours later. Aromas from the airlock of “grass, lemon, grapefruit, and peach” according to Sophie. To me it smelled like super fresh Motueka.

Left to ferment at ambient (likely around 18 °C), CO2 almost absent at day 9, hence racked to keg with dry whole hops in hop spider. Spunding valve attached, set to 15 PSI. 

Approx 1 week in keg, then attached to CO2 at 15 PSI and placed in kegerator.

A tiny dry hop addition (this year's harvest)
Praise be.

Tasting Notes

At 6.7%, this is a surprisingly crushable beer. Sourness – tick. Hoppiness – tick. Funk – tick! Overall, I feel like this was mission accomplished. That being said, it transpires that my fears of over-bittering with the flameout addition were well-founded. I do think this would be a more-balanced beer with a whirlpool addition below isomerisation temperature, or a larger dry hop. On re-brew, I would aim for half the IBUs or none at all, allowing sweetness to balance the sourness.


Vibrant orange when held in the right light. A degree of haze – this looks like a NEIPA, drinks like a sour.


Fresh hops, pineapple, tropical fruits, funk.


Similar to the smell, though the fruity aroma is slightly betrayed by the degree of bitterness. Without the bitterness I feel that the beer would drink like  sour, hoppy, funky fruit juice. Yum! There’s a touch of saison yeast character, though not massive.


Some fullness from the reasonable chloride addition, lovely dry finish, surprisingly no alcohol burn. The carbonation brightens the beer beautifully.

Drinkability and notes

A dangerous drop – very drinkable, refreshing, sour beer, though also one that can be sipped slowly and contemplated. A pleasing first attempt at brewing with Brett.


Once again, if you end up brewing this beer or having any questions, please reach out and get in touch in the comments section below. Cheers to funk!



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