[bmweigel]

I am researching to make a Berliner Weiss by the kettle souring method. I just want to check and make sure that I have the process correct.

1. mash & sparge like normal
2. collect wort and drop pH to 4ish using lactice acid
3. boil the wort 60min - no hops or it will stop the bacteria you will add
4. chill
5. pitch lactobacillus once wort is about 40C (104F about) and check pH ever day until pH of 3 is reached.
6. boil 10 min to kill lactobacillus. Hops can be added at this point
7. chill to proper yeast range and pitch yeast
8 ferment like normal.

Are these steps correct?
What happens if I don't drop the pH before pitching the lactobacillus?
How do I bitter this beer with such a short hop boil without overloading with hop flavour and aroma?
Can I boil shorter for the first boil, and longer for the 2nd one after the lactobacillus does its job?

I look forward to reading the responses

[Stevie]

All the answers are here - http://www.milkthefunk.com/wiki/Berliner_Weissbier

Hands down best resource for general sour brewing.

[mabrungard]

Steps 1 & 2 are generally OK, but the pH only needs to be dropped below 4.5 as long as you are pitching a good lacto starter immediately. You don't need to boil that raw wort yet. Just acidify and pitch the lacto. Then cover the fermenter to prevent oxygen ingress. When the wort is down to a desirable pH (I find 3.3 to 3.5 acceptable), then you will boil that soured wort and add hops. Yeast is added to the boiled wort to produce alcohol since lacto isn't much of an alcohol producer.

[tesgüino]

This is an old thread, but found it researching kettle souring. I get tracking the pH, but can it go too far. What if I don't get the chance to do the second boil for, say a week? Would a lower pH ruin the beer?

[a10t2]

If you let the lacto ferment unchecked for a week, it will probably be unbearably sour. Probably not "ruined" in a food safety sense, just a glass full of heartburn.

[reverseapachemaster]

The ph will drop enough that the bacteria will create an intolerable condition and stop fermenting. You might get a little below 3 before that happens.

Bigger problem IMO is that the wort is just sitting there with exposure to oxygen and potential for any contaminant to ferment unwelcome flavors into the beer.

[tesgüino]

I have the cart before the horse situation here. Did minimal research and started brewing. Did more research during the mash and now I'm waiting for the wort to come to a boil while looking for more information. My worse offense seems to be not making a starter with the Omega OLY-605. Although this may make the delay in the second boil less of an issue? I did prepare a water bath with a fish tank heater to keep the temperature from dropping. Given the longer lacto ferment and lack of starter, what sounds like a good temperature to hold? I've read numbers from 75 to 100 degrees. The plan is to transfer to a carboy and purge the head space with CO2. Should that be enough top prevent contamination / oxygenation?

 

[danpixley]

The Omega OYL-605 blend is a great blend, and as long it is not expired then you don't need to make a starter with it.  What you have is correct, it acidifies well between room temp up to 100°F.  It will sour faster at the higher end of that range.

Also, I agree with Adam regarding leaving it for a week before pitching.  The LAB will self-terminate before making an "acid bomb", and the greater risk will be the excess sugars that are lying around during that time.  The low pH will help ward off a lot of microbes, but any yeast that gets in there will have a go at fermentation (and sometimes yeast is included in the packages of Lactobacillus from some yeast labs).