A couple of Questions about Brewing Sour Beer

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Mar 5, 2017
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I plan to start brewing sour beers and have been reading some threads, but still have several questions that I did not find the answers to:

1. First, can you just add lactic acid to the final beer/during any point of the brewing process to make a sour beer? Instead of adding Lactobacillus and let it convert to lactic acid. Will that make a difference on the flavor and what?

2. For the Co-Sour and Post-sour methods, you don't need to boil the unhopped wort for a long time or reaching boiling temperature. I understand that there is no hop to isomerise and no need to boil for long time to pasteurize the wort, but boiling has a third purpose for brewing normal beer is the hot break of proteins and other unpleasant compounds. If not boiling to a certain level, these unpleasant compounds and proteins won't harm sour beer?

3. You cannot brew Sour IPA by the Co-Sour and Post-sour methods, is that correct? Because these two methods not allow adding hop on the hot side, but only on the cold side (dry hopping) when the sourness reaches what you aim for, so that you won't get much bitterness but only aroma. In this way, you can only brewing sour IPA by pre-sour (kettle sour), since you can add hops during normal boiling to create certain level of bitterness without stopping the souring process which has finished before adding hops. Am I understanding it right?

I am a newbie of sour brewing. Any advices will be much appreciated.

Brewer dad

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Aug 15, 2020
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I’ll try to answer you best as I can here, but my experience is not extensive. The pinned thread you’ve also commented in has a bunch of information which explains some of this, which is that L. Plantarum is very hop sensitive. But once it has done its work hops will not undo it so to speak.

1. Lactic acid definitively adjusts PH but I don’t know that anyone adds it until the beer becomes “sour”.

2. See link in other thread I posted.

3. Not necessarily. See the link I posted and read what he has to say about hop tea.

It sounds like you want to brew a sour IPA and want to try the co or post sour method, give it a shot! I recommend(depending on what kind of yeats/bitterness/etc you want) maybe doing a co sour, dry hop it, and add hop tea at packaging.

You seem to be concerned about not boiling it so why not boil as normal to eliminate that portion of it. Or alternatively do a raw ale and just mind your temperatures. That part I think is also partially dependent upon what kind of ipa(hazy/west coast) you want. I’ve literally never brewed an IPA in my three years brewing but have done a few sours with these methods, so take that with a grain of salt. Regardless of what you decide I’m sure it’ll be awesome!