Done as a kettle sour. Perform mash, sparge and lauter as usual. Once desired volume is in kettle, perform quick 10 minute boil to kill any bacteria. Chill to 95*F and add lactic acid to drop pH to 4.0-4.4. Add Omega OYL-605 and let sour until pH 3.2 is reached (or desired sourness).
After kettle souring is complete, move to boil and proceed as usual. Use 2 packs of US-05 yeast for fermentation due to sour level being unfavorable for yeast.
After primary fermentation complete, mash up cranberries and rack beer into secondary fermenter on top of the cranberries. 7 days is my standard for this one but adjust as desired.