Souring a stout

[AGBrewer]

Going to do a ten gallon batch of O'flannagains standard stout, I want to sour half of it. Is it benefitial or necessary to add the soured 24oz back to the fermenter before, after, or during fermentation of the unsoured portion? I have never done a soured beer before(at least not on purpose!) so I am excited to try it. Thanks

 

[cheezydemon]

Do you mean that you want to let half of a 5 gallon batch sit out and sour? I don't understand. You sour a batch. Did you split it into 2 fermenters? If so I would set out 1/2 as much to sour.

 

[zoebisch01]

What I would recommend is to take a small portion of the malt, grind it, throw it in like a 1.5 ratio with 130 °F water and set it in a warm place. An oven with the light on should work fine. In about 24 hours you will have gotten fairly sour, taste a little to see. The longer you go the more sour. You want to boil the resulting strained liquid to kill off any Lactobacillus. It sounds like you are doing partial mash?

I'd say to get the proper amount of sour you want about oh maybe 2 lbs or so of it for a 10 gallon batch. The thing is this, and the reason I say to strain the liquid and boil, is I am not sure how you should proceed if this isn't an AG batch. With Ag, what I would do is mash normally with the remaining part of the recipe, and sparge the soured mash seperately.

Oh yeah, the above post does bring out a good point. If you want a soured aspect (like Guiness does) then use the method I prescribe above, or you *could* just take half of your unfermented wort, (before the boil) bring it up to 130 °F and keep it at roughly that temperature for about 15 to 20 hrs. Taste it as you go. Then boil when it hits the sourness you want to arrest the Lactobacillus. Otherwise you'll have a runaway lacto ferment.

 

[AGBrewer]

Ok, I am doing ten gallons but only want to sour five gallons of it. What I will do is take 24oz of preboil wort add some crushed grains to it and let is sour for a week. Then I will add that into the fermenter with five gallons of wort. The other five gallons will be left alone. My question is should the soured 24oz go into the fermenter after fermentation of the five gallons minus the 24oz or does it matter. Sorry if I was unclear

 

[Kai]

I understand there would still be fermentables in the soured portion, so I'd pasteurise it and add it to the fermenter while the unsoured portion was still fermenting. But this is purely theoretical, I've never done this.

 

[CBBaron]

Speaking of soured stout. Would it be reasonable to do a sour fermentation like a Flanders Red with a Stout? This would be very similar to the traditional way serving beer by blending aged/soured beer with young/mild. I think this would be an interesting experiment to try.

As for a sour mash, I have seen several recipes that use Acid malt instead of doing a sour mash. It is claimed to give the same result with less risk and trouble.

Craig