The Beerery's Sauegut Reactor

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:

Tested pH:

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.
Added notes.

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.

Do you use a PRV on your fermentation keg for this? My sour worts that have been innoculated with grain have built up a significant amount of pressure. I learned quickly to attach my spunding valve.

I just strap a brew belt on the keg and keep it in a cooler. I suppose you could use a temp probe if you were trying to target a specific temp, but I’ve found lacto to be just fine anywhere within 10-20 degrees of 100F.

Yup PRV set to 5psi, that way I can dispense directly. Kunze is pretty explicit about 48c so I maintain that within a degree.

How do you add back the new wort to the reactor keg?  I am thinking about O2 ingress on that process and how best to limit that.

Seems like too much effort for me. Is the driving force the desire to stay RHB? 88% lactic would work just as well.

Actually, the treatise claims other benefits that are not present from acid additions alone, including better digestibility, if I am reading that correctly.

that will get the pH down, but the industrial lactose is said to be one dimensional compared to a sauergut.

Had to edit an autocorrect!

Right, but we are not talking about lowering to a Berliner level of pH. This is would a relatively tiny amount of acid, certainly less than taste threshold.

Addition of sulfited low o2 wort gently, and purge vessel.

No actually far from, there are a host of benefits.

Roughly 2l per 20l batch, actually its far above the taste threshold and one of the driving flavors of the majority of examples.

What are the other benefits?

What kind of mash are you running that 2L of 88% lactic would be needed to get you to 5.2? I use between 1-3ml at most.

ETA - I guess as you are using full volume mashing, it would take a larger amount of acid to hit 5.2. “Normal” mash thicknesses would require much less than the taste threshold.

Sorry, I was speaking of the amount of sauergut added (2l). Kunze is pretty adamant that mineral acid ( 88%) is a last resort, and he isn’t a RHG elitist.

Umm Benefits off the top of my head:

More oxidation reduction power
Better enzyme actions
Better extract yield
More zinc( healthier and faster fermentations)
Probiotics( digestibility and nutritional value)
Shorter mash times
Inhibits lox ( the major staling enzyme)
Flavor enhancement (source of grape flavors in the beers)

I think one of the book pages above lists most of them.

Maybe I’m the only one…but part of me wants to try this approach to control the pH on a Dry Irish Stout?  :smiley:

Isn’t that how’s Guinness is rumored to do it?

Yup!

All of the rumors I’ve seen say it is a separate sour mashed wort that is added post main mash. Again, rumors. I’ve also seen denials.

Maybe it was more to combat the high RA from the hard water. It could easily have been a technique of the past as more water treatment is done these days.

Whatever microorganisms are added pre-boil is killed in the boil. If your post-boil addition is pre-chilling then you’re killing off whatever is alive at the stage unless you are able to chill at a truly rapid speed.

This is really cool Bryan. Thanks for sharing your process with SG production.

Albeit it seems like quite a bit of work, but if one has the desire and time for it, then I could see how the benefits of homemade SG (not lactic acid from a bottle) could get you even closer to the real deal.

I most definitely have noticed differences when fermenting worts with straight lacto (in terms of flavor/aroma/acidity) compared to beers I have tried to dose with bottled lactic acid. The bottled products almost gives me some fake buttery notes to the beer (diacetyl) that I simply did not care for.

Nope! Guinness does not sour their dark wort. Their water is almost Pilsen quality.

You might benefit from reading Zymurgy someday.