First Sour Wort Help

I'm planning on doing my first Sour Wort (first sour period actually) for a Berliner Weisse in two day. I've been doing a lot of reading preparing for this, but real world experience trumps books any day. I wanted to run my process through the fine folks here at HBT.

1) Mash and sparge
2) Bring wort to a boil (to kill anything in there)
3) Transfer to wort to sanitized cooler (about 2 qt head space)
4) Drop temperature to ~120F
5) Pitch WYeast 5335 Lacto.
6) Wrap the cooler with saran wrap to prevent anything from getting in.
7) Let it sit for 2-3 days.
8) Continue as a normal brew day after.

What I'm unsure about is people talking about purging with CO2 to prevent off flavors/aromas. I haven't been able to pinpoint what exactly the purge is for exactly, what is the oxygen doing? I really don't want to have to go out and buy a CO2 cartridge for limited use (I don't keg, play paintball, etc). If this is an absolute must, then does anyone know of an alternative?

If the PH drops below 3.5 (my understanding of when it becomes a problem for yeast), is there a good way to fix this instead of pitching Brett instead of my planned US05? This will all be taking place at a friend's house as I can't fit the operation in my apartment. I don't have a good way to monitor the PH over the course of 2-3 days. So I have to blindly go into brew day and hope for the best.

Any sage advice will be appreciated.

Rather than wrapping the cooler with saran wrap, place a sheet of it on top of your wort, inside the cooler, to prevent exposure. Oxygen won't necessarily harm your beer at this stage, provided you don't let mold in, but it'll make the lacto produce some weird smells. Think cheese, sweaty socks, or even urine. I've had lacto do this in a starter, and while it actually doesn't taste too bad, the smell is hard to get past.

I believe the "oxygen inside the vessel" issue is a much bigger issue when you are sour mashing/worting with grain because you WILL be pitching many other bugs besides the lacto. In you situation where you will be pitching a clean, single strain of lacto into pasteurized wort in a sanitized vessel then I would be much less concerned, but keeping the exposure to the atmosphere at a minimum is doing due diligence.

If you want to purge the headspace then you can probably pour some plain unflavored seltzer water in your cooler just before resting the lid on the cooler; then let some of the co2 off-gas to purge the headspace; then tighten down the lid. I also believe an option would be to creatively utilize dry-ice.

As for pH, the only "real way" of monitoring is to use a device for measuring pH. Obviously the best option is a quality pH meter but that can be excessive unless you have major intentions of implementing pH control in your brewing process. The best judge of the sour is actually tasting the souring wort since both pH and TA are what affect the perceived sourness. Wait until it's about how sour you want it and then finish up your brewday. If you're concerned about possible illness-causing bacteria then simply spit the sample out and rinse well. There's no point in talking about pH and yeast strains if you have no way of measuring pH. Pick one of the oft used strains and roll with it (us05, kolsch, etc).

My first experience with berliner weisse went like this:
-Mash and sparge to postboil volume using a mashout of 175F into fermenter bucket
-Cool to 115F
-Pitch lacto strain (plantarum + sauerkraut cultures)
-Taste a couple times over the next few days until it seemed about right
-Cool to pitching temp and pitch WLP670 slurry (sacc/brett blend)
-No boiling at any point but I'm "okay" with having live bacteria in my system
-The result is a refreshingly tart beverage that is delicate in flavor profiles (really easy to drink glass after glass)

stpug said:

As for pH, the only "real way" of monitoring is to use a device for measuring pH.

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I'm planning on picking up PH test strips as they are pretty cheap, so I'll be able to see the final PH after the sour wort. I'm more concerned of if there is anything I can do if it drops below the 3.5 threshold. A lot of the methods I know for raising the PH are traditionally only done for the mash (Calcium Carbonate and Sodium Bicarbonate), I have no experience if adding these to the wort will cause any problems/off-flavors.

The main reason I'm doing a full 90 min boil after is because of grain bill of 50%/50% Pilsner/Wheat. I want to reduce any possibility of DMS from the Pilsner.

Thanks for the advice though.

Vamptrump said:

I'm planning on picking up PH test strips as they are pretty cheap, so I'll be able to see the final PH after the sour wort. I'm more concerned of if there is anything I can do if it drops below the 3.5 threshold. A lot of the methods I know for raising the PH are traditionally only done for the mash (Calcium Carbonate and Sodium Bicarbonate), I have no experience if adding these to the wort will cause any problems/off-flavors.

The main reason I'm doing a full 90 min boil after is because of grain bill of 50%/50% Pilsner/Wheat. I want to reduce any possibility of DMS from the Pilsner.

Thanks for the advice though.

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I think you can get decent ballpark pH figures using strips. I would feel comfortable using them for ballpark figures. They're fairly inexpensive and long-lasting.

I've never dealt with a situation where I was too acidic and needed to do something about it so I can't really help here. However, the common theme in berliner brewing is that folks end up not as sour as they wanted. In this case, after fermentation, you can dose with a little straight lactic acid 88% to increase the sour/tart perception.

I also used a 50/50 pils/wheat grist with the no boil method. My understanding from what I gathered was you either go "all in" with the no boil method, or you perform a standard batch boil. I had initially planned on a ~200F pasteruization or quick 15 minute boil, but the more I read the information alluded to the fact that the closer you get boiling the more the SMM precursors are converted to DMS. If you never boil and keep the pasteruization temperature low then those precursors are not converted to DMS and the flavor threshold of SMM is much higher than DMS. At least that's what I gathered in my travels

Lots of guys here do short boils to no ill effect. I do 20 min to sterilize, never had a dms issue

With my terrible string of luck recently I don't want to be that 1% that ends up with dms issues. I like to error on caution. Plus it gives me more time just to relax and hangout with friends around the pot.

Update:

I ended up dumping the wort. The temperature dropped too much. I left the cooler at a friend's house, and he was terrified of it, so it didn't get topped off with hot water to keep the temperature stable. Next time I'll utilize a heat pad with a carboy or kettle.

Needless to say, the cooler stunk of lacto. To the point everyone around me at a brew out was making comments. I took a PH reading with strips, but the strips highest number was 4.4 and it didn't change the strip color. I then took a quick sample drink after scrapping away the top layer. Just like I was expecting with the knowledge from the PH strip, there was 0 sourness. It didn't taste bad, just not what I wanted. It wasn't worth bothering saving the wort and boiling for a non-sour berliner weisse. I ended up picking up a few ingredients to make a saison.

Some good lessons were learned. I'll try it again eventually, maybe in a smaller 1 gallon batch at home that I can better control.

Thanks for posting back. That's a bummer than it didn't work out. I'm sure you learned a lot from the hands-on attempt and have some new ideas planned for a future batch. Better luck with that one and let us know how it goes when you eventually get around to it.

Seems your process was fine, bummer that you dumped it. You probably could have warmed it back up in a kettle and let it sit there a little longer. I usually sour mash in a cooler but I basically sour the entire batch, because more thermal mass helps hold the temps so I don't have to open the lid and add water. I take samples from the drain valve too, which is a nice way to see where you are without introducing oxygen.

There are a million and one ways to do this, but here's my process which has worked out very well for me:
- Mash as usual in my 48qt cooler.
- Add the full amount of sparge water heated to about 100F and stir well.
- When the temp falls to about 125F, throw in a handful of uncrushed base malt.
- Place a layer of plastic wrap on the surface, smoothing any air bubbles out to the sides.
- Close the lid, place blankets over and around the cooler, put a space heater nearby if it's not already a hot area.
- Sample as often as you like from the drain valve until it tastes sour enough, usually 24 hrs is ideal.
- Drain, boil, pitch yeast as usual.
- Enjoy!

One thing to note is that perceived sourness will increase once the sugars are fermented out, so be sure to stop when it seems almost sour enough for your tastes. Don't be afraid to give it another go, you'll find what works for you if you keep at it.

Yeah, everything seemed right by the book, but for some reason it didn't want to keep temperature in the cooler for 2.5-3 days. I think going forward now (for most of my beers), I'm going to do a small 1 gallon trial batch before moving it up to 5. At least with a 1 gallon Berliner Weisse I can keep the temperature warm for the lacto in a slow cooker.

I would have kept it probably, if it wasn't for the fact that it needed more time, and I didn't want to risk it dumping in the car. I was supposed to finish it off at the LHBS on Saturday, if I would have kept it I would have been hauling back 2 batches of wort, plus equipment.

I'm in the process of getting my own home. When I have that, I'm looking forward to doing beers that I can't do at my friend's on my equipment. I don't really have any sort of temperature control when I store with him. For now, I'll continue to buy my sours until I have everything ironed out.

What other methods have people used to keep temp at around 110 degrees for souring? Aquarium heaters seem to max out at 90 degrees, and I'm not sure if that would be warm enough.

My preferred method is to use omega labs lacto, and then you just need to keep it around 80°F.

I already posted my technique, it works great for me. Simply mash the full volume in my cooler mash tun, drop to ~125F, toss in a handful of fresh grain and wrap in blankets in a warm area for a day or two. Should be plenty sour by that time without losing much temp.