Beer Forum

Hello what is involve in Kettle souring ?. I am trying to brew my first Berliner Weisse that why I am asking.

Basically after you run off your mash into the kettle & collect your full volume you let it set for an extended period of time. You want to keep it between 90-110F (32-43C) the entire time. The amount of time is going to depend, but I would say 5-7 hours at minimum.

You can also do a sour mash, which is pretty much the same thing, only holding your mash at those temps for a similar amount of time post conversion.

When I have done it, I make up some work (I usually just use some DME and hot water) and then add in a couple handfuls of unmilled malted barley. You will need something to inoculate the thing with bacteria, either a pitch of bacteria or the malt method I used. Then I put it into a container that can keep it warm, either a carboy or a kettle or something. You really want to keep out the oxygen, so put some plastic wrap on the surface of the liquid (or fill the carboy to the neck, I use a 3gal one).

I keep mine warm with a back heating pad. I have also tried putting it in a cardboard box with a lamp (don't burn the house down). After a couple days it is pretty sour, then I boil for 10 minute and toss some hops in there, chill and ferment with US-05. My personal favorite was done like that with some galaxy hops just before chilling and then I added the guts of 2 passion fruits to the fermentor when it was basically done.

Another note, I tried using those probiotic caps (lacto acedophylus I think) full of white powder to inoculate wort a couple times, and it tasted like vomit every time. Others say it is ok, but I think it is wretched.

It is critical that your sweet wort be unhopped (to allow lacto to grow) and acidified to a pH of under 4.5 (to avoid spoiling organisms). It is also critical to prevent any oxygen or air contact with the wort (spoiling organisms would grow, lacto doesn't need oxygen). Keeping the wort warm (around 100F) helps speed the lacto growth.

I find that it takes way more than a few hours to effectively sour wort. I've found that it will take a couple of days to drop the wort pH into the low 3 range. Reducing pH to 3.5 is the minimum that I would consider and many would find a pH of 3.1 to 3.2 to produce a pleasing weisse.

I've tried the commercial lacto products from Wyeast and White, but I find them too mono-culture and they tend to have a 1-dimensional flavor. I recently had a weisse soured with the capsules and found that was also 1-dimensional. I find the most interesting lacto is from the handful of grain method. I routinely get both floral and fruity notes from the lacto and an intense sour. The secret to that method is to follow the preparation notes I gave above...acidify to under 4.5 and keep all air away! It might smell a little funky for a day or so, but that should give way to the smooth lactic aroma. Do create a lacto starter with the handful of grain method so that you don't screw up a whole batch of wort!

After the wort is soured to your specification, then boil the wort and lightly hop the wort (under 10 IBU). Then chill and pitch with a clean yeast. A German Ale yeast is good, but a clean American yeast is good too. I've used US-05 dry yeast and it will ferment at 3.1 pH and it produces a very nice weisse.

Milk the Funk's wiki will tell you everything you need to know:

http://www.milkthefunk.com/wiki/Sour_Worting
http://www.milkthefunk.com/wiki/Berliner_Weissbier

A technique presented at the Craft Brewers Conference year before last called for the use of Greek yogurt as the lacto culture. The gives you the complex lacto sourness you want along with the advantage of being really cheap. One of the local breweries I have ties to uses this for kettle souring berliner weisse and a number of other sours. All have been excellent.

Bugeater wrote:A technique presented at the Craft Brewers Conference year before last called for the use of Greek yogurt as the lacto culture. The gives you the complex lacto sourness you want along with the advantage of being really cheap. One of the local breweries I have ties to uses this for kettle souring berliner weisse and a number of other sours. All have been excellent.

Did they plate out the bacteria from the yogurt?
If not, can you describe how one would go about this on the homebrew level?

They sanitize the outside of the tub they bought at the grocery store and then dumped the contents into the wort. Easily done at the home brew level. One or two of the single serving containers is plenty for a 5 - 10 gal batch.