Sour Mash Berliner Weisse

I am going be brewing this beer this weekend, I just wanted to make sure my technique is correct. I plan on mashing the grain on Thursday and letting it sit until Sunday morning allowing it to sour. After I have mashed in I read that I should put plastic wrap on top of the mash to prevent mold and unwanted fungus from forming, is this correct? Also I plan on keeoing this mash as close to 90F as possible. Then on Sunday I will remove the wort, boil for 15 min, chill and ferment with US-05. Does this sound correct? Suonds really easy. If anyone has any suggestions or comments please leave them!

Keep the mash around 110F range to encourage lacto.

So just mash at 110 and let it sit for 3 days, should a mash-out with a gallon of 180f water before I boil for 15 minutes?

You need to take it through the normal mashing temps at some point. If I was doing a sour mash, I think I would make a small mash in a stainless pot a week or so before brew day, keeping it warm with a heating pad, and once nice and sour I would put it in the fridge to hold. Then mash the rest of the grain normally, and add the runnings from the sour mash directly to the kettle.

Ok, with that in mind then I will start this tonight. I don’t have any base grain on me but I do have extract and specialty grain, I should be able to make a gallon of 1.030 gravity wort with the extract and just add a handful of specialty grain to this to make the sour mash, correct?
Thanks for your help

If the specialty grain isn’t roasted or kilned it should work, but I can’t think of many specialty grains that would fit that requirement. You could add a yogurt with active cultures to the extract.

I have Carapils, this should work I think.

I don’t know if the drying part of the conversion to a crystal malt is hot enough to kill the enzymes. Give it a shot and you’ll know if it’s working pretty quickly.