best way to mash sour berliner weisse

[mrkrausen]

So I made my first attempt at a berliner weisse using a similar method outlined in this thread https://www.homebrewtalk.com/showthread.php?t=460657. I mashed on the stove top in an aluminum pot with 5 pounds of pilsner malt and let it drop below 120 before pitching the WLP320. I then put plastic wrap directly over the grain/wort and then another piece covering the pot to try and keep out as much oxygen as possible. I then put the pot in a bucket of hot water that I placed a fermwrap around the bucket connected to a temp controller that I was able to maintain ~96 degrees with. I kept this going for three days, occasionally having to top off with more water. About once a day I would lift the top plastic wrap and hit it with about 30 seconds of co2. The smell would go back and forth between somewhat bready, to cheesy like parmesan. From what I understand a bad bacteria outpaced the lacto and created isovaleric acid and that's why it smells like cheese. I plan on tossing it because from what I've read that will transfer to the beer and won't dissipate with time. I'm wondering if I wasn't able to keep it warm enough or just too much oxygen got in. I want to make another attempt at this but want to make sure I cover all of my bases prior. Any help would be appreciated. Pictures to come.

 

[arnobg]

Did you drop the pH to around 4.5 with acid before pitching the lacto?

 

[mrkrausen]

I did not. The recipe I was following didn't say to. It was my understanding that the lactic was dropping the ph. The thread starter and a couple of others seemed to have success.

 

[Gnomebrewer]

A much more reliable method is to sour in the kettle rather than the mash. Mash and sparge as normal, boil for 10 minutes or so (no hops), use lactic or phosphoric acid to bring the pH down to 4.5, chill to about 100F then add your Lactobacillus source. Keep at 100F until wort pH is where you want it, then boil again with hops and continue as for a normal beer.

 

[mrkrausen]

with that kettle souring method approximately how long would you say it would take the lacto to sour?

 

[Gnomebrewer]

I've only done one - it reached 3.75 at 24 hours, and 3.50 at 48 hours.

 

[arnobg]

You want to drop the pH with lactic acid to 4.5 before pitching your lacto culture. This keeps any other bugs at bay and allows your lacto to do it's work without competing with any other source of bacteria. Sounds like you may have gotten something else in there possibly

 

[mrkrausen]

I brew in a keggle so I'm not sure I'll be able to maintain the temp for 24 hours. What if I used the method I did before, but use 1/4 to 1/2 of the acid malt for the whole grain bill to drop the ph and then proceed with the method I did before? I would also purge with co2 prior to and just after adding the lacto.

 

[crane]

I've never been worried about maintaining temps for kettle souring. I also don't trust plastic wrap to keep oxygen out if my boil kettle. After sparging I bring the wort to boil, then cool to 100F and knock out into a carboy or Corny keg. Purge with CO2 and seal it up. I've found that in a carboy it will still be up in the 80s the next day. Last one I used a goodbelly shot for my lacto source and it was down to 3.77 after 22hrs and 3.55 after 36hrs.

 

[mrkrausen]

I was hoping to avoid souring anything on the cold side (carboy/keg), but I may end up going this route. Thanks for all the replies.

 

[ZeroBrewThirty]

24 hours is more than enough time to get lacto character. I don't worry about temp either, I pitch around 90 with my lacto starter and then follow up with yeast pitch after 24 hours.

Three days is a waste and inviting contaminates.