I had some recent discussions with some folks over some VERY fresh Bavarian samples. There were flavors in these beers that I could not replicate exactly, however I had some batches that had hints of it. Looking back though notes, I noticed the high pH of my Barke malts, and how I had to use more acid malt than normal. I then had a revelation after reading Kunze for the nth time.. Acid malt=Lacto, Lacto= flavors I was tasting, more lacto=more flavor... Enter Sauergut.
I am not really one to tip toe around a subject so I jumped right in. I did a 2l low oxygen Minimash of pima, did not boil. I then inoculated that with 8oz of fresh pima Purged with co2 and set it in the Fermentation fridge at 48c for 5 days :
In the meantime.. I used an old dorm fridge I had, equipped it with a hair dryer, and temperature controller.
On day 5 I brewed a full scale batch using the SG as the mash acid. I had observed at pH drop to around 3.5, guesstimated acid % and added about 1l. Hit a 5.26 mash ph, and did a standard Kunze mash. I then cooled that mash to 48c using my herms coil and cold water in the HLT. I acidified the mash with the remaining 1l, and ran that off into a purged keg, and placed it into the reactor at 48c.
It then sat in the reactor for 5 more days until the next brew. I pulled a sample:
Ran the calcs(titration) and dosed the brew that day hoping for 5.2 mash pH.
Not too shabby.
I know recover roughly 1L more wort per mash, that goes right back into the reactor that is purged and left to sit until next brew.
I dose both mash AND boil, and they both have positive effects.
Firstly the SG itself tastes like glorious low oxygen wort tainted with orange juice. SG is the sole creator of the grape flavor in these beers (grape, grape koolaid, yougurt, tang). When added to the mash it has great acid AND oxygen buffering capabilities. PH will lock in and you will have much better oxidation protection, so much infact I only consume 10ppm sulfites from my dough in until I pitch yeast( and that is with a cold trub seperation process). The host of other benefits are outlined in Kunze.
When added to the boil as a knock out addition, you add more grape, but you also get a beautiful fresh wort aroma and flavor that carries over into the finished beer. You know the commercial beers you taste this fresh wort in are using a knockout addition of SG. Paulaner pils, and Andechs Vollbier Hell, are some really nice examples of the power of SG, they have SG notes galore.
Some excerpts from my stash.