Musing upon lactic acid vs. acid malt (with respect to flavor impact)

[Silver_Is_Money]

Per Weyermann's website the use of 8% by weight in the grist of saurmalz will depart a (sometimes highly prized) souring to the flavor of the beer. This I presume is due to the presence of lactobacillus. But would 88% lactic acid when used to achieve the same the same mEq/L level of acidity impart the exact same level of flavor souring? Is lactobacillus (or as much of it as for acidulated malt) present in 88% lactic acid?

 

[ajdelange]

No, the bacteria are long gone by the time the acid is bottled. The additional flavorings, which are indeed highly appreciated by some and completely unrecognized by others, come from the fact that the lactic acid is on a MALT in the sauermalz implementation. It is the malt that adds the extra complexity. It should be pretty plain that lactic acid in a bottle is going to pretty one-dimensional in flavour but to really appreciate the difference you will have to get some of each and taste them.

 

[techbrau]

LAB produce a wide rainbow of fermentation products, not just lactic acid. The same way that yeast does when it produces ethanol.

Using technical acid is akin to foregoing the alcoholic fermentation of the yeast and just adding some everclear to barley tea. Or trying to make a sour beer by just dumping a bottle of acid into the fermenter.

Acid malt has a lot more of these LAB-derived flavor compounds than technical acid does. But acid malt still pales in comparison to using sour wort (sauergut) - basically just a small amount of kettle soured wort - to adjust your pH in the mash and boil.

Every single lager brewed in Germany is required by law to use either acid malt or sour wort for pH adjustment, and 99% of breweries are using sour wort because it's cheaper and also provides a superior result. Like AJ says, the flavor impact of biological acidification in German lagers is completely unrecognized by most people but it is a critical aspect of achieving an authentic tasting result.

Think about the refreshing, yogurty tang of a Berliner Weisse - and then imagine imparting just a little bit of that to a light lager like Helles. Sour wort is only used at rates between 1.5% and 5% of the final volume for making most lagers, which certainly isn't a lot but it's enough to impart a background flavor to a delicate beer.

 

[ajdelange]

Good point about the goodies in both sauermalz and sauergut added by the bacteria, not just the malt.

You refer to sauergut as 'kettle soured wort'. I have seen descriptions (from German brewers) of systems in which separate tanks are maintained with kettle wort which is inoculated with L strains or in which the sauergut is drawn off as needed and replenished with fresh wort to maintain a fairly constant volume and keep the fermentation going. Is this not the usual case?

 

[Silver_Is_Money]

Both of you have provided great information.

 

[techbrau]

Good point about the goodies in both sauermalz and sauergut added by the bacteria, not just the malt.

You refer to sauergut as 'kettle soured wort'. I have seen descriptions (from German brewers) of systems in which separate tanks are maintained with kettle wort which is inoculated with L strains or in which the sauergut is drawn off as needed and replenished with fresh wort to maintain a fairly constant volume and keep the fermentation going. Is this not the usual case?

That's exactly how they do it commercially, and in practice at commercial scale the souring takes place within only a couple of hours of topping up. The sauergut reactors are kept going pretty much indefinitely.

For a homebrewer, it may be too much to keep a reactor going unless you brew very frequently. In that case, making sauergut a batch at a time ends up being akin to making a mini mash of a couple liters of wort a day or two before you brew, kettle souring it, and then using it during your normal brew day to adjust pH.

 

[Sadu]

I'd be keen to give this soured wort method a go for my next pale lager.

I gather it's like making a mini berliner-weisse then measuring the pH and drawing some off into the mash of the main batch?

How do you go about deciding how much to use?

 

[techbrau]

Instructions for making and using sour wort:

https://www.homebrewtalk.com/showpost.php?p=7879730&postcount=6

 

[Silver_Is_Money]

Can I conclude from all of this that if I was intentionally trying to sour a beer, 88% lactic acid would be a terrible choice, since it would not likely be effective in meeting the end goal, and since there are far more effective means at hand?

It seems that many of us home brewers shy away from using lactic acid for mash acidification (pH adjustment) due to an instilled fear that it will impart off flavors akin to lactobacillus souring. Seeing as there are no lactobacillus present in 88% lactic acid, perhaps it has rather undeservedly been given a bad rap.

 

[ajdelange]

No. It just wouldn't be the best choice as it would not lend any of the flavors from the malt/wort or other products of a ferment as when sauermalz is prepared by spraying sauergut onto malt, or sauermalz made by allowing the L delbruekii on malt to undergo lactic fermentation or lacto fermentation of wortr (sauergut). As has been noted lots of people wouldn't even know the difference.

 

[rabeb25]

Here is my method, I have had and maintained my SG reactor for over a year and hundreds of brews. My Acid % is 1.8% and I add 350-500ml per batch for acidifaction on all of my beers.

http://www.********************/ingredients/a-sauergut-reactor/

 

[betarhoalphadelta]

So how would I go about this in a real brew?

Let's say I want to brew 10.5-11gal batch of Oktoberfest.

Here's what I'm thinking. Make a sour mash in a small pot of only ~32 oz (roughly 2.5% of finished volume). Hold that pot in a larger pot of water for 24-48 hours using my sous vide circulator to hold it at 110 deg F for optimal souring. Don't bother with lauter. Just let it all sit together in the pot.

I use RO+mineral addition water, so make up my water normally but without adding lactic acid as I would normally do.

Mash in my O'fest as usual, dump in the quart of sour mash at the start of the mash, mash and lauter normally. Boil normally, follow all standard brewing procedure from this point forward.

Does that sound about right?

 

[SanPancho]

My Acid % is 1.8% and I add 350-500ml per batch for acidifaction on all of my beers.

so if i assume correctly, you have to titrate the sourwort to figure out the lactic acid %, and then you can plug that into something like BrunWater to figure out how much you'll need to add for pH adjustment in the mash?

and as far as adding to the kettle, is there a pH you are targeting, or is it just to introduce more of the flavors?

 

[rabeb25]

so if i assume correctly, you have to titrate the sourwort to figure out the lactic acid %, and then you can plug that into something like BrunWater to figure out how much you'll need to add for pH adjustment in the mash?

and as far as adding to the kettle, is there a pH you are targeting, or is it just to introduce more of the flavors?

Yup thats correct.

Mash between 5.2-5.4, knock out 5.0-5.1.

 

[rabeb25]

So how would I go about this in a real brew?

Let's say I want to brew 10.5-11gal batch of Oktoberfest.

Here's what I'm thinking. Make a sour mash in a small pot of only ~32 oz (roughly 2.5% of finished volume). Hold that pot in a larger pot of water for 24-48 hours using my sous vide circulator to hold it at 110 deg F for optimal souring. Don't bother with lauter. Just let it all sit together in the pot.

I use RO+mineral addition water, so make up my water normally but without adding lactic acid as I would normally do.

Mash in my O'fest as usual, dump in the quart of sour mash at the start of the mash, mash and lauter normally. Boil normally, follow all standard brewing procedure from this point forward.

Does that sound about right?

Roughly, yes. Obviously there are some finer points, like titration, acid amounts, mash pH target, etc. Also I keep 48c (118F) for my reactor.

 

[rudager999]

Has anyone tried adding acid whey from yogurt to their wort? I'm planning on taking a few liters off my next batch of wit to try souring with a small amount of whey left over from my yogurt production.

 

[JimRausch]

Just FYI, the AHA forum had an article on making Kvass a couple months ago, and included was a simple method for making a sourmash a day ahead of the main mash.

 

[SanPancho]

For a homebrewer, it may be too much to keep a reactor going unless you brew very frequently.

So kettle souring is a breeze, no problem there. But as you allude to here, the issue is frequency. But i believe its ok to store the saeurgut cold for a few weeks, so we could make a big batch and then slowly use it up id think. And youd just titrate once as opposed to every time you brew.

Would it be self defeating to use a pure LAB culture for the saeuergut as opposed to raw malt? (Probiotics pills, yogurt, etc). Is sauerguts "power" in its micro diversity from using whats on the grain, or simply from being a biologically derived acidifying agent?

If storing long term is it necessary to rack it off of the bacteria trub layer that sediments on the bottom of jar?

Is no-boil on the wort something that's considered essential to sauergut, or just personal preference?

 

[rabeb25]

Personally I wouldn't store it cold, I would want those guys up and awake, as they are great reducing agents (dissolved oxygen) when rocking.

In trials, the pure cultures where much less preferred in sensory analysis. There is a multitude of flora and fauna on the grain that makes for a much better flavor.

I always ditch 300ml of the first sediment and haze, then get my dose.

I chose no boil because I step mash, and my step mashing regimen pasteurizes the wort anyways. I have never used raw, non mash out wort, as everything I brew gets step mashed with a mash out.

If I was starting a new culture today, and I didn't want to keep a reactor. I would make a 10p wort using a stepped mash (mash out for sure), hit the wort with lactic and knock the ph down to 4 or so and run that off into a purged container (small keg, mason jars, etc). Hold that for 3-4 days at 48c. Titrate with a wine kit, to get acid%, and then store at room temp until use.

HTH's

Bryan

 

[SanPancho]

Personally I wouldn't store it cold, I would want those guys up and awake, as they are great reducing agents (dissolved oxygen) when rocking.

when you say those guys do you mean lactic bacteria?

as in, the intent is to dose your wort with actual live LAB in the form of sauergut?

 

[rabeb25]

when you say those guys do you mean lactic bacteria?



as in, the intent is to dose your wort with actual live LAB in the form of sauergut?

Yes, sorry for being unclear.

 

[SanPancho]

ah, ok. now i see your point. i assumed you pastuerized the sauergut as well to prevent any lactic activity in your beer.

but if you're adding it at mash its not a concern. as for kettle additions, i assume they're done at flameout so they'd be pastuerized as well?

 

[rabeb25]

Yup, exactly. Although if I do a boil addition its done at 10 minutes remaining.

 

[z-bob]

This is one of the most interesting threads I've seen here in a long time. For some reason it never occurred to me that soured wort could be added to the mash to acidify it. (I've heard of adding it later to make sour beers) Might be a good (and traditional! and cheap!) way to deal with the high-bicarbonate water I have to deal with here.

Do you titrate the sauergut, and calculate how much to add? Or just use experience to get it close? Or some combination; dump in enough to get it almost there and then use a pH meter to dial it in?

 

[rabeb25]

This is one of the most interesting threads I've seen here in a long time. For some reason it never occurred to me that soured wort could be added to the mash to acidify it. (I've heard of adding it later to make sour beers) Might be a good (and traditional! and cheap!) way to deal with the high-bicarbonate water I have to deal with here.

Do you titrate the sauergut, and calculate how much to add? Or just use experience to get it close? Or some combination; dump in enough to get it almost there and then use a pH meter to dial it in?

Yea its neat stuff, easy to do and very traditional, cheap and flavorful!

http://www.********************/ingredients/a-sauergut-reactor/

thats my method, that I have had great luck with. On the blog post it shows how to titrate for lactic acid. Usually you will be about 1.2-1.7%

Good luck!

 

[z-bob]

Why are you doing the lactic fermentation low-oxygen? I really thought that was an aerobic process.

 

[rabeb25]

Why are you doing the lactic fermentation low-oxygen? I really thought that was an aerobic process.

The making of the wort was low oxygen. Thats part of a bigger brewing mantra. You are correct on the fermentation side.

 

[z-bob]

Thanks.

BTW, I used to use all RO water plus calcium salts. (CaCl2 and gypsum)
Now I'm using 50% RO water and calcium salts plus sauermalz for the mash, and RO for the sparge.
My next brew will be all tapwater for the mash (plus gypsum, sauermalz, and hydrochloric acid), and RO sparge.

I wasn't planning to take it any farther than that, but it bothers me that I'm using technical grade HCl instead of food grade. Sauergut would eliminate the need for sauermalz and HCl

 

[z-bob]

Well, I was wrong about lacto being an aerobic fermentation. I found this BYO article about it: http://byo.com/malt/item/889-how-to-make-a-sour-mash-techniques And the temperature is more important than I thought.

It might be doable in a kitchen oven with the light on for a source of heat. I've done that before for yogurt. I've also made yogurt in a wide-mouth thermos.

 

[z-bob]

Yea its neat stuff, easy to do and very traditional, cheap and flavorful!

http://www.********************/ingredients/a-sauergut-reactor/

thats my method, that I have had great luck with. On the blog post it shows how to titrate for lactic acid. Usually you will be about 1.2-1.7%

Good luck!

What gravity is your starting mini-mash, or does it really matter? I'm thinking of doing a 1-gallon sauergut, starting with 2 pounds of pilsner malt and an ounce of sauermalz (holding back 4 ounces of the pils until after the mash) That will give an OG of about 1.048. I don't have a temperature controlled box, but I could wrap the jug up in a blanket with a heating pad and Inkbird controller set to about 115 degrees...

And then what? The problem is, I don't brew very often. Do I hold it at 115 forever, or refrigerate it? Or build it up to several gallons (like a sour dough starter) and then pressure can bombers of it for later? (650 ml is about how much I'll need per batch if I use straight Rochester water)

If I was brewing every week I'd draw off however much I needed, and replace it with that much wort drawn off of that day's brew, and it should keep healthy for months.

 

[rabeb25]

12p for the sauergut should be fine. In the professional brewhouse the Sg reactor gets filled with 1:1 dilution of first runnings and water. So it's probably close enough. I target 10p for mine. The reason is not to really dilute the mash with the large addition acid.

Your heating method should work I would bump it up to 118 though, 48c is what you want. I would keep it at that temp until the acid % reaches 2. That is the maximum acid amount the Sg can generate. I would then just leave it at room temp until use.

In that blog post if you blow up picture 1 and 3, it should tell you all you need to know!

Good luck!

 

[z-bob]

This weekend I'll probably do a dry-run; see if I can maintain 118° in a gallon of water, then I'll start a batch. I really like the idea of using a traditional method to brew with the local water w/o having to run to the store for RO water all the time. I'd like to brew again in 2 or 3 weeks. (I'm behind this year)

Would sauermalz be better than pilsner malt for inoculating the wort?

 

[rabeb25]

No. The sauergut on that malt is cured and dry. Use normal pils, has all you need!