Lactobacillus

Say I wanted to make a clone of Guinness Extra Stout could I add lactose to the wort and then add lactobacillus to the fermenter to give it a little sourness?

Will lactobacillus consume maltose?






Dave

I suppose you could do that, but I wouldn't. Guinness doesn't have a sour note, rather it's roasted and malty, a touch bitter with a dry finish.

For the bitter roasted flavors, use roasted and/or black barley. Some chocolate malt wouldn't hurt, and you could even add some coffee or espresso to the mix. Add an English variety of hops early in the boil to extract bitterness, but go easy on (or omit) the finishing hops.

I bet I just raised a few eyebrows and conjured more questions in your brain, but that's all part of the forum!

I don't think it would be out of line to add lactobacillus to a portion of the mash and allow to sour. I do detect the slight sourness in Guiness Draught. Even BJCP style guidlines would lead you to believe that this is acceptable in a Dry Irish Stout.

The dryness comes from the use of roasted unmalted
barley in addition to pale malt, moderate to high hop bitterness, and
good attenuation. Flaked unmalted barley may also be used to add
creaminess. A small percentage (perhaps 3%) of soured beer is
sometimes added for complexity (generally by Guinness only). Water
typically has moderate carbonate hardness, although high levels will
not give the classic dry finish.
Vital Statistics: OG: 1.036 – 1.050
IBUs: 30 – 45 FG: 1.007 – 1.011
SRM: 25 – 40+ ABV: 4 – 5%
Commercial Examples: Guinness Draught Stout (also canned),
Murphy's Stout, Beamish Stout, O’Hara’s Celtic Stout, Dorothy
Goodbody’s Wholesome Stout, Orkney Dragonhead Stout, Brooklyn
Dry Stout, Old Dominion Stout, Goose Island Dublin Stout, Arbor
Brewing Faricy Fest Irish Stout

I have read that Guiness does include, intentionally, some soured beer. Thing is, I'm pretty sure the sour beer they add to the mix is then pasturized. If you just add a little bit of infected beer, how do you prevent the whole beer from becoming infected? A Lambic-Guiness does not sound like Good Drinks.

If you wanted to do this, I'd expose a small amount of the beer to the bacteria (maybe 5%), let it sour, then figure out the best way of killing the bacteria (heating the beer? one of those chemicals that winemakers use?) before adding it back.

As I recall it, Papazian's Toad Spit Stout recipe (a Guinness clone) says something like, "The only thing this recipe lacks is the unique 'tang' that the real thing has. This is achieved by adding three percent pasteurized soured beer."

At least that's what I think it says. It's at home and I'm at work, so I could be wrong.

I think that's where I remember that from. I haven't been able to find my copy of the Bible for months, though. I'm sure of it, though.

The soured beer for Guinness is only used in certain varieties of their bottled export and in Africa. I read at the Guinness storehouse tour that this style is very popular in Nigeria where the Guinness folks see this as a growth market.

the_bird said:

I have read that Guiness does include, intentionally, some soured beer. Thing is, I'm pretty sure the sour beer they add to the mix is then pasturized. If you just add a little bit of infected beer, how do you prevent the whole beer from becoming infected? A Lambic-Guiness does not sound like Good Drinks.

If you wanted to do this, I'd expose a small amount of the beer to the bacteria (maybe 5%), let it sour, then figure out the best way of killing the bacteria (heating the beer? one of those chemicals that winemakers use?) before adding it back.

Click to expand...

You mention pasteurization as if it's some kind of magical process that isn't attainable at home. However, it's as simple as heating the beer to ~160-170 and maintaining that temperature for about 10 minutes. The heat will kill the bacteria, and you can add the soured beer without worry.

As to my original post in this thread...I stand corrected about the use of lactobacillus in Guinness!

Oh, I know. I'm just not sure whether heating the beer will impact the soured portion in any other way, which is why I was wondering if it was the *best* way to do it.

the_bird said:

Oh, I know. I'm just not sure whether heating the beer will impact the soured portion in any other way, which is why I was wondering if it was the *best* way to do it.

Click to expand...

I doubt those temps will hurt the beer much, especially in the amount we're talking (about a pint per 5 gallons). Allowing it to come to a boil would probably be a bad idea, though.