New Giveaway - Wort Monster Conical Fermeneter!

Home Brew Forums > Home Brewing Beer > Fermentation & Yeast > Lactobacillus delbrueckii questions




Reply
 
LinkBack Thread Tools Display Modes
Old 06-22-2010, 06:06 AM   #1
shanecb
Kvlt Brewer
Feedback Score: 0 reviews
 
shanecb's Avatar
Recipes 
 
Join Date: Mar 2010
Location: Pittsburgh, PA
Posts: 1,139
Liked 19 Times on 17 Posts
Likes Given: 9

Default Lactobacillus delbrueckii questions

I've been fine-tuning a berliner weiss recipe that I plan to do in a couple of weeks, and I realized there were some things about lactobacillus delbrueckii that I don't know. I have a vial of the White Labs strain if it's relevant.

1) What exactly is it that the lactobacillus delbrueckii is eating in the wort? I know one subspecies eats only lactose, but I can't imagine that being the case when it is used in beer. What sort of sugars is it eating specifically? To my knowledge, lactobacillus delbrueckii does not produce alcohol of any type. If it is eating some of the same sugars that the saccharomyces (in my case, a Kolsch yeast) would be fermenting, then wouldn't an ABV estimate by, say, BeerSmith, actually be too high since not all of those sugars would be available for conversion to alcohol now? I'd like to take that into account if possible, so I know what my actual achieved ABV would be.

2) Does lactobacillus delbrueckii fall out of suspension like yeast would? Is it something particularly visible? I'm going to be making a lacto starter, and don't really want to pitch a liter of weak, bad beer into the batch if I don't have to. It would be nice if the lacto could be settled to the bottom like yeast, so just that is pitched into the fermenter.




__________________
A particular love for ancient, obsolete, or lesser-known style from both the US and abroad.

We are the Sons of Winter and Stars
We ́ve come from a far beyond time
Forever the fire burns in our hearts
Our world shall never die
- Wintersun
shanecb is offline
 
Reply With Quote Quick reply to this message
Old 06-22-2010, 08:00 AM   #2
denimglen
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2006
Location: Auckland, New Zealand
Posts: 438
Liked 1 Times on 1 Posts
Likes Given: 1

Default

Quote:
Originally Posted by shanecb View Post
...Does lactobacillus delbrueckii fall out of suspension like yeast would?...
I haven't actually used Lacto. D. (WL strain) in a real beer yet but did build it up in a starter to freeze some off.

It floccs out pretty well. Seems to do it's thing, clump up and drop out pretty quick. I would compare it to a medium-high flocculating Sacc strain.

I wouldn't know if it the combination of Lacto and Sacc in the same wort would change it's flocculation characteristics though.


__________________
denimglen is offline
 
Reply With Quote Quick reply to this message
Old 06-22-2010, 03:34 PM   #3
shanecb
Kvlt Brewer
Feedback Score: 0 reviews
 
shanecb's Avatar
Recipes 
 
Join Date: Mar 2010
Location: Pittsburgh, PA
Posts: 1,139
Liked 19 Times on 17 Posts
Likes Given: 9

Default

Quote:
Originally Posted by denimglen View Post
I haven't actually used Lacto. D. (WL strain) in a real beer yet but did build it up in a starter to freeze some off.

It floccs out pretty well. Seems to do it's thing, clump up and drop out pretty quick. I would compare it to a medium-high flocculating Sacc strain.

I wouldn't know if it the combination of Lacto and Sacc in the same wort would change it's flocculation characteristics though.
Great, thank you! I was hoping that would be the case.
__________________
A particular love for ancient, obsolete, or lesser-known style from both the US and abroad.

We are the Sons of Winter and Stars
We ́ve come from a far beyond time
Forever the fire burns in our hearts
Our world shall never die
- Wintersun
shanecb is offline
 
Reply With Quote Quick reply to this message
Old 06-22-2010, 07:40 PM   #4
onemanlan
Feedback Score: 0 reviews
Recipes 
 
Join Date: Apr 2010
Location: Alabama
Posts: 94
Liked 1 Times on 1 Posts

Default

I think Lactobacillus delbrueckii consumes lactose in homofermentive metabolism producing lactic acid as a bi-product. The bacteria is quite small so unless it forms a bio-film or clumps together in suspension which seems to be common in beer-related microbes.

http://www.bd.com/ds/technicalCenter/inserts/Lactobacilli_MRS_Agar_&_Broth.pdf

__________________
onemanlan is offline
 
Reply With Quote Quick reply to this message
Old 06-23-2010, 12:35 AM   #5
shanecb
Kvlt Brewer
Feedback Score: 0 reviews
 
shanecb's Avatar
Recipes 
 
Join Date: Mar 2010
Location: Pittsburgh, PA
Posts: 1,139
Liked 19 Times on 17 Posts
Likes Given: 9

Default

Quote:
Originally Posted by onemanlan View Post
I think Lactobacillus delbrueckii consumes lactose in homofermentive metabolism producing lactic acid as a bi-product. The bacteria is quite small so unless it forms a bio-film or clumps together in suspension which seems to be common in beer-related microbes.

http://www.bd.com/ds/technicalCenter/inserts/Lactobacilli_MRS_Agar_&_Broth.pdf
Are those the same subspecies as the one that is available for brewing? I actually don't know which subspecies is used in brewing, and I haven't found it yet, I just know that *a* subspecies eats up only lactose. It could very well be the same one, though.

So, assuming that lactose is primarily what it is hitting, is there actually that much lactose in a typical wort? How much does the lacto really have to work with? I'd like to think that if it's limited, adding a little additional lacto could really bump up the sourness if wanted.
__________________
A particular love for ancient, obsolete, or lesser-known style from both the US and abroad.

We are the Sons of Winter and Stars
We ́ve come from a far beyond time
Forever the fire burns in our hearts
Our world shall never die
- Wintersun
shanecb is offline
 
Reply With Quote Quick reply to this message
Old 06-23-2010, 12:48 PM   #6
Oldsock
Feedback Score: 0 reviews
Recipes 
 
Join Date: Sep 2007
Location: DC, Washington DC
Posts: 2,974
Liked 109 Times on 80 Posts
Likes Given: 41

Default

Just used pure WL lacto for the first time. It did seems to clump and flocc out, but I'm a little suspicious that it was actually a wild yeast strain that got in there (not much sourness in the starter or beer, and it took a couple days to get going).

Wild Brews suggests Lacto Del it is a homofermentive glucose eating lactic acid producing strain. Not sure how accurate that is though. The Wyeast strain seems to keep making lactic acid long after the yeast would have consumed all the glucose.

I’ve long suspected the same ABV lowering effect of acid production. That said it would depend on the relative amount of CO2 being produced, and anyway lactobacillus is only supposed to make a max of 1% lactic acid (so the effect is pretty minimal).

Might be a good post to send to the BBB, there are many more scientific minded sour brewers on there.

__________________

Check out The Mad Fermentationist for my adventures in fermentation (cheese, bread, ginger beer plant, and of course plenty of funky beer).

Oldsock is offline
 
Reply With Quote Quick reply to this message
Old 06-23-2010, 01:44 PM   #7
JohnMc
Feedback Score: 0 reviews
Recipes 
 
Join Date: May 2010
Location: NC
Posts: 265
Liked 4 Times on 4 Posts
Likes Given: 1

Default

Quote:
I know one subspecies eats only lactose
If it eats lactose, it can eat galactose and glucose, the simple sugars that come from that disaccharide. Beyond that, bacteria are pretty good at scavenging carbon/energy compounds. Lactic acid itself is produced from pyruvic acid, a product of glycolysis (glucose breakdown).
__________________
JohnMc is offline
 
Reply With Quote Quick reply to this message
Old 06-23-2010, 04:15 PM   #8
onemanlan
Feedback Score: 0 reviews
Recipes 
 
Join Date: Apr 2010
Location: Alabama
Posts: 94
Liked 1 Times on 1 Posts

Default

Quote:
Originally Posted by JohnMc View Post
If it eats lactose, it can eat galactose and glucose, the simple sugars that come from that disaccharide. Beyond that, bacteria are pretty good at scavenging carbon/energy compounds. Lactic acid itself is produced from pyruvic acid, a product of glycolysis (glucose breakdown).
Good call on on it being a disaccharides though. I had completely forgot about it.

Lactic acid is a product of homofermative lactic acid metabolism where pyruvate is turned into lactic acid consuming 2 NADH. Glycolysis only takes 1Glucose -> 2 Pyruvate at the gain of +2 ATP and +2 NADH. The NAD+/NADH cycle is balanced in that way.

1Glucose -> 2Pyruvate -> 2Lactic acid - With major intermediates left out.
__________________
onemanlan is offline
 
Reply With Quote Quick reply to this message
Old 06-23-2010, 04:26 PM   #9
shanecb
Kvlt Brewer
Feedback Score: 0 reviews
 
shanecb's Avatar
Recipes 
 
Join Date: Mar 2010
Location: Pittsburgh, PA
Posts: 1,139
Liked 19 Times on 17 Posts
Likes Given: 9

Default

Quote:
Originally Posted by JohnMc View Post
If it eats lactose, it can eat galactose and glucose, the simple sugars that come from that disaccharide. Beyond that, bacteria are pretty good at scavenging carbon/energy compounds. Lactic acid itself is produced from pyruvic acid, a product of glycolysis (glucose breakdown).
Quote:
Originally Posted by Oldsock View Post
Just used pure WL lacto for the first time. It did seems to clump and flocc out, but I'm a little suspicious that it was actually a wild yeast strain that got in there (not much sourness in the starter or beer, and it took a couple days to get going).

Wild Brews suggests Lacto Del it is a homofermentive glucose eating lactic acid producing strain. Not sure how accurate that is though. The Wyeast strain seems to keep making lactic acid long after the yeast would have consumed all the glucose.

I’ve long suspected the same ABV lowering effect of acid production. That said it would depend on the relative amount of CO2 being produced, and anyway lactobacillus is only supposed to make a max of 1% lactic acid (so the effect is pretty minimal).

Might be a good post to send to the BBB, there are many more scientific minded sour brewers on there.
Thanks for the replies! So now it seems to be that it could be breaking down some glucose. I found it odd that it could have been a particular subspecies that only went after lactose, since I couldn't find any information leading me to believe there would be a significant amount of lactose in a typical wort. I'm now further wondering if adding some lactose would increase the possible sourness level without messing with the ABV, since only the lacto del would be able to do anything with it. I gave White Labs a call yesterday, and am just waiting to see if they get back to me.

Pardon, but what is the BBB?
__________________
A particular love for ancient, obsolete, or lesser-known style from both the US and abroad.

We are the Sons of Winter and Stars
We ́ve come from a far beyond time
Forever the fire burns in our hearts
Our world shall never die
- Wintersun
shanecb is offline
 
Reply With Quote Quick reply to this message
Old 06-23-2010, 04:30 PM   #10
shanecb
Kvlt Brewer
Feedback Score: 0 reviews
 
shanecb's Avatar
Recipes 
 
Join Date: Mar 2010
Location: Pittsburgh, PA
Posts: 1,139
Liked 19 Times on 17 Posts
Likes Given: 9

Default

Quote:
Originally Posted by onemanlan View Post
Good call on on it being a disaccharides though. I had completely forgot about it.

Lactic acid is a product of homofermative lactic acid metabolism where pyruvate is turned into lactic acid consuming 2 NADH. Glycolysis only takes 1Glucose -> 2 Pyruvate at the gain of +2 ATP and +2 NADH. The NAD+/NADH cycle is balanced in that way.

1Glucose -> 2Pyruvate -> 2Lactic acid - With major intermediates left out.
Biology I'd forgotten comes back to bite me in the ass again

I've based my original post on this wiki page: http://en.wikipedia.org/wiki/Lactobacillus_delbrueckii_subsp._bulgaricus

It's from there that I got wondering if the brewing subspecies is only a lactose eater or not. I'm thinking it's not at this point, but if it WAS that could be where it's getting the glucose to turn into lactic acid. As I said in a previous post, though, I haven't yet run across anything that leads me to believe there is any significant amount of lactose in a typical wort. I'm guessing the brewing subspecies of lacto del just starts at glucose?


__________________
A particular love for ancient, obsolete, or lesser-known style from both the US and abroad.

We are the Sons of Winter and Stars
We ́ve come from a far beyond time
Forever the fire burns in our hearts
Our world shall never die
- Wintersun
shanecb is offline
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options
Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lactobacillus Jonnio General Beer Discussion 9 01-31-2013 02:04 PM
Lactobacillus cultivation shanecb DIY Projects 4 10-05-2010 07:17 PM
lactobacillus delbrueckii and airlock activity Reverend JC Recipes/Ingredients 9 11-14-2008 02:25 PM
lactobacillus and O2 the_bird General Techniques 8 01-13-2008 03:20 PM
Lactobacillus jager Recipes/Ingredients 10 11-14-2006 02:44 PM