bufff! that's opening the door to a new dimension! hehehe
Some yeasts produce a little tartness, but barely noticeable.
If what you want is a sour beer you have basically three options:
- lactic acid -> inmediate but crappy and artificial way of souring, you won't get any flavour from the lactic acid, just acidity/tartness
- kettle sour -> brewday becomes 2 brewdays and you get a lot of lacto-flavour. for a saison you might want to age it for at least 3 months so the lacto flavour mellows a little -> it "locks" sourness!
- lactobacillus to secondary -> it will take at least 1 year to sour to the same level and it will keep evolving and souring more the longer you keep it
I always make kettle sours, that is:
1- Calculate your recipe for extra 15' of boil.
2- Do the mash and boil for 15' with no hops
3- chill to 35ºC
4- add ~5ml/10L of lactic acid 88% or until you get <4.5PH (wait some minutes to test the ph again and remember PH is logaritmic, be careful with your corrections) -> this prevents infections
5- add lactobacillus: i've used lallemand sour mix (mild flavor) and inner health IBS capsules (strong flavor). Pitch around 10Billion cells per 10L (1g of the sour mix or 1 capsule of the IBS thingy). Don't use dairy stuff, you might get other bacteria you don't want and you will add different flavors to your beer
6- sanitize the kettle lid, put it on, wrap it with cling wrap and keep it around 30-35ºC for 18-24h until you reach your desired PH target (3.4-3.8 depending on the style of beer). I put in my fermenter fridge with a heating mat (specific for homebrewing)
7- once souring is done, do your boil as usual
With this technique you can brew many styles: berliner weisse, gose, flanders red, "farmhouse ales / saisons", etc.
I would start with something simple if I were you. Something fast like a gose (salt and coriander) or beliner weisse, so you understand how it goes.
But only sour doesn't make a "farmhouse ale / saison", you also want brett... which is another universe. Brett can also give certain tartness, but far far away from a sour beer.
Brett takes a long time to develop flavour. The faster I've done it was with WLP670 american farmhouse blend (mix of saison yeast + brett.). Other option is to select a clean saison yeast and then another brett and blend them together, although for the first time I would go easy...
There's a lot to study here. Too much for a simple post. I recommend you google a little, read some and come back with particular questions.
https://www.brewersfriend.com/homebrew/recipe/view/658983/brett-saison
allaboutbeer.com/article/homebrewing-with-brettanomyces/
https://learn.kegerator.com/brewing-with-brettanomyces/
https://beerandbrewing.com/the-many-faces-of-brett-best-homebrew-practices/
https://www.love2brew.com/Articles.asp?ID=637
https://www.love2brew.com/Articles.asp?ID=654
https://www.love2brew.com/Articles.asp?ID=661
https://www.themadfermentationist.com/2008/06/all-about-brettanomyces.html
http://www.wyeastlab.com/wild-beer-brewing
http://draftmag.com/brett-geeks-come-ride-trinitys-magical-brettanomyces-tour/
and... MILKTHEFUNK!
http://www.milkthefunk.com/
Recipe suggestion:
70% Pilsner
20% Wheat malt
6% Flaked wheat
4% Aromatic/munich malt
OG 1046
FG 1003
ABV 5.6%
IBU 8 (Styrian Goldings at 60')
Mash/sparge water PH 5.4, low minerals, Cl to SO4 Ratio balanced-to-malty
MASH:
- 40ºC, Mash in
- 45ºC, Time: 15 min, Beta Glucanase Low, avoid grain gumming up
- 55ºC, Time: 15 min, Beta Glucanase High, improve head
- 67ºC, Time: 60 min, Saccharification/Beta-amylase, extract main fermentable sugars
- 72ºC, Time: 20 min, Glyco-protein/Alpha-amylase, stabilize head/foam
- 78ºC, Time: 10 min, Mash out, improve extraction
- 78ºC, Sparge, improve extraction
Kettle sour as described and boil as usual
Pitch White Labs - American Farmhouse Blend WLP670 at 20ºC
Add 30g/10L of light toast oak chips (pre-boiled in express cooker for 20')
After 1 day, raise 1ºC/day to 22ºC
After 1 week, raise 1ºC/day to 24ºC
When you need the fermenter fridge for other beer, just take this one out, cover it well and put it somewhere around 20ºC
Ferment for 8 weeks
Bottle at 3.2CO2 vol.
Condition at least 2 months (better 4 months) with bottles on the side (helps to prevent pellicle)
I've tried but I haven't been able to make a decent brett in less than 4 months.
They say you can doing 100% brett. fermentation, but that's a different story...