All about Sour beers #2

Please welcome articles written by the Brewie Ambassadors. Get familiar with ingredients, recipes, homebrewing techniques and get every must have knowledge from first hand!

See the first part of Thomas’ article here.

The process

To make use of most of Brewie’s functions we need to be a bit creative in the recipe setup. You need to make 2 recipes – one for the pre-souring and one for the boil after souring.

Brewie recipes

1. The pre souring
Creating a recipe for kettle souring are not much different than for a “normal” beer but it has a few tweaks in term of boil and cooling.

Here’s a quick recipe setup:

  • Mash in at 60C
  • Water amount – I prefer a wet mash at 3-4 x grain weight.
  • Sparge at 77C for 60 min
  • Enter fermentables weight

Mash schedule:

  • 64C for 120min
  • 77C for 10min

Boil schedule:

  • Delayed hopping 2 min
  • Cooling to 35C
  • Water:
  • Automatic or manual inlet – up to you
  • Automatic cooling

2. The boil
This recipe is for boiling only so no need to do a sparge – just a short mash.

Recipe setup:

  • Mash in at 80C
  • Enter something for the water amount
  • No sparge
  • Enter something for the fermentables weight

Mash schedule:

  • 80C for 5min
  • Boil schedule:
  • 45 or 75min (pale or pilsner)
  • Cooling to 18C


  • Manual water inlet
  • Automatic cooling

Nothing special about mashing a sour beer wort but try to target high fermentability. 64-66C should make sure you’re on target for a dry, sour beer.

Same here – go about this process as normal. I do recommend the full hour sparge as this will ensure full extraction and a clear wort.

It’s a good idea to make sure most bacteria are wiped out before you add the sour culture. This way you make sure the lactobacillus has the wort to itself. Usually this step is done at 85-90C for 10 minutes or so then cool but this isn’t supported by Brewie yet. So for the Brewie we do a very short boil – just a couple of minutes – and without hops. This is why the pre souring recipe has a delayed hopping boil without hops. Hops also prevent bacterial growth so you don’t want this before after you have soured your wort.

To make sure no wort is left in the mash tank:

  • Use a flat device like a lid to lightly press the Brewie bag then remove it along with the false bottom
  • Use the syringe to suck up any remaining wort in the mash tank. The tubing makes it possible to suck up wort from the drain hole as well.

Cooling is set as high as 35C to accommodate the best possible pitch temp for your souring culture.

The pasteurization in the previous step makes sure you start out with a sanitized wort but if you want to keep the wort for your added bacteria you need to make it inhospitable for most other bacteria. To achieve this we can drop pH to at or below 4.5.

It will take about 20ml of 80% lactic acid to drop the wort down to 4.5 for a pilsner/wheat grist. A pH meter is highly recommended. That way you can add acid in steps and verify. …but if it’s off by a couple of decimals it shouldn’t be a problem.

Now that you have a pasteurized, low pH wort its time to add some bacteria! Empty 10 capsules of L. plantarum or pitch your Lallemand WildBrew. Lactobacillus can produce butyric acid if exposed to oxygen giving a smell that reminds of vomit. Most of it will be removed during boil but to avoid it you can use plastic wrap. You will need 2 sheets long enough to cover the wort, up along the sides and be draped over the edges. Connect the 2 sheets before placing it over the wort. Start by letting the plastic wrap touch the wort at the middle of the tank and try to trap as little air as possible under it. When you reach the edges, drape the rest of the wrap over the edges.

An extra step to avoid butyric acid is to bubble some CO2 through the wort before you close it off with the plastic wrap.

The souring process will take anywhere from 18-48 hours and should give you a pH in the 3.3-3.7 range. Again a pH meter makes this much easier. If you don’t have one just wait to the second day before moving on.

Mash tank cleaning
To keep the mash tank clean during the souring pour some hot water in the mash tank. You can use a little detergent as well if you rinse properly afterwards. Scrub it down properly and go to the Drain-menu on your Brewie. Now you need to make sure you don’t drain your precious wort but only the mash tank!!!

If you want to keep it sanitized pour in a litre of sanitizer solution and drain again.

Now that you have reached your desired pH level it’s time to boil. Remember to remove the plastic wrap before anything! Go to the 2nd recipe and remember to input manual water inlet before you hit Brew.

Prepare the hops and add some anti foaming drops to the wort.

Some recommend just a 15 min boil for sour beers – don’t. There is just as much DMS in the wort as a “normal” wort so boil for the full 90 min if you’re using pilsner. In the 2nd recipe I have shortened the boil by 15 min since it goes through a boil phase in the 1st recipe as well.

As a measure to keeping your system clean the wort is heated to 80C before its pumped over to the mash tank. This will kill off the lactobacillus so you don’t have to worry about contaminating the mash side.

Add a flocculation agent (whirlfloc etc) and yeast nutrition (preferably zinc based like Servomyces) at 15 min before boil end.

No boil at all is actually an option as well but I won’t cover this here.

Same as any other beer in the Brewie targeting whatever pitch temp optimal for your choice of yeast.

Choice of yeast
Any yeast will work but you will need more cells to start with as the wort isn’t the best working environment with the low pH. Sour beers aren’t necessarily yeast driven so any clean, highly attenuating yeast will work fine. 2 packs of US-05 will serve you well 🙂

You can add an adjunct at any time during the fermentation but I recommend adding after the most vigorous fermentation has taken place and before it has reached final gravity. This way you will contain aroma and any oxygen introduced will be scrubbed off by the still active yeast.

Amount depends on what you add but for fruit puree I have found 1kg gives a good balance. In the case of fruit there is a big difference between peach and raspberries in intensity for example.

Contamination and cleaning
Lactobacillus are not heat resistant so the risk of contamination is next to nothing. To be sure make sure you do the mash tank cleaning procedure and heat the sour wort before pumping it over to the mash tank.

Normal cleaning (Full clean) should be sufficient after this but a sanitizing clean can be used to make sure.

Sour beer recipes are coming, see them in the upcoming part of All about Sour beer!

Thomas Valsø Solberg

Beer at the push of a button

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