Sour imp stout, plz help

[the_ale_scale]

I have a solid imp stout recipe and wanted to sour it using acid malt and lacto in the 2ndry. Does anyone have any suggestions on how much acid malt to maybe use? Thank you in advance

 

[kingwood-kid]

It takes a ton of sour malt to drop the pH to sour beer levels. And lacto won't do anything in secondary, as the ABV and probably the IBUs will be too high to allow it to do anything. If you want to sour an Imperial Stout, the best way is to draw off a half-gallon or so of unhopped wort and add just lacto for a few days at the warmest place you can find, then bring it to a boil to sterilize, then blend into the main wort to taste.

 

[the_ale_scale]

Very interesting. Thank you