I understood it to be an acid for pH adjustment only. It’s a way to skirt the German brewing rules and add a flavor that is considered key to German beer.
OTOH, Brewtan B and Metabisulfates are verboten but are used anyway.
It seems some rules are OK to break while others are not. [emoji2369]
Brewbama brings up a good point. Sauergut is a method to adjust mash and wort PH that complied with the German purity law……fundamentally.
Breweries that do LODO have the ability to strip the brewery water of O2 by forcing CO2 or N2 up through columns of water. The DO water is stored in large tanks under N2 or CO2. I’ve seen this at Brauerei Schönram in Germany and at Sierra Nevada Mills River. N-Meta is a US homebrewer workaround as far as I know.
Brewtan-B may or may not be RHG compiant. If it is not in the finished beer it is ok. For example the commercial equivalent to polyklar is ok, as it is not in the finished beer, so processing aids are allowed.
It is a pH adjustment. It is the result of a lacto fermentation, which are generally anerobic, so they arent utilizing O2. O2 in one of those fermentstions can allow other organisms to take off and give undesired odors and flavors.
Sauergut gets around the RHG prohibition of using industrial derived acids to adjust the mash. The classic way would be to do a long acid rest to drop the pH.
As mentioned, it is a pH adjustment, but it also has a flavor contribution. I’m a firm believer that lactic acid as pH adjustment also adds something flavor-wise to a pilsner. In this case, it’s going to have a more complex contribution, just as a kettle sour tastes different than pure lactic acid added to beer.
That being said, I personally dislike the strong grape flavor that you sometimes get in a light German beer. I haven’t gone the sauergut route yet but may try it in small quantities to see if I like it.
This is a WAG, but perhaps the addition of Sauermalz may achieve a similar flavor result to the sauergut, without the need for cultivating a sauergut reactor. I adjust pH with both Sauermalz and salts; once in a great while, I will instead adjust with liquid lactic or phosphoric acid. Might be time for a side by side…if someone is using sauergut.
Sauergut is said to add a white wine flavor. I’ve gotten a Welches Grape juice flavor in some of my beers and ones club members have brewed, which may be from the yeast or old grain - anyone know more about tha
There was a discussion here years back - it is believed to be ethyl heptanoate, which is an ester that some yeast strains (ale strains in particular) can produce. The precursor is heptanal, which comes from malt.
I remember the conversation, but the malt having heptanal is what i didn’t remember. Thanks.
I usually get that grape juice flavor in lagers, matbe because there are fewer competing esters to hide it. Ive tasted it in some lagers inngermany.
This is where I could see, hypothetically, where saurgut could play a factor. Some bacteria can produce methyl anthranilate (which is one of the primary flavorings in Grape Kool Aid). If any of these are present in sauergut, then maybe this flavor could make it into the finished beer.
This is all a WAG, but that’s the road I’d go down if I were looking to do a deeper dive into this.
If using crushed grain as an inoculant you would almost certainly get some yeast and other critters that ferment aerobically. Even at low acid rest temperatures it is improbable that the aerobic fermenting organisms would have sufficient time for something in the mash to break down starches to sugar and ferment them before you raised the temperature to the next rest. You would have to add a simple sugar source and hope what you added plus whatever is on the grain doesn’t produce any undesirable flavors.
The instructions for culturing sauergut from grain are to incubate at 118F. I think the elevated temp is to discourage wild yeast growth and favor lactobacillus, specifically amyloliticus.