Why the difference in ABV for the same beer if BB aged?

Although I'm no expert, my guess is that water slowly leaches out, leaving a slightly higher concentration of alcohol.

 

The beer will definitely gain abv from aging in the barrel. There is residual alcohol pickup from the spirit soaked into the wood and a gain of up to 2% can be seen. There can be over a gallon of spirits soaked into the oak. Evaporation of water from the beer can also occur. Some base beers for BA beers are different as they are brewed specifically for BA.

 

They don't actually use barrels at all, they just pour some bourbon right in with the base beer and get it directly to market.

 

No, the wood can only absorb so much liquid before it gets saturated.

 

There can be as much as a pint of liquor left over in the barrel when the brewery receives it, no hidden yeast or magic wood.

 

Good question, OP. I've often wondered this myself.

 

The alcohol would evaporate first.

 

I've seen some barrel aged beers with the same ABV as their base beer though, too.

 

Pretty much what everyone says. BA beers served where they are sourced are quite another thing altogether to in the flavor cos its notes and their order in prominence will change over time and can do so in as short as a few hours. I was amazed at how some BA's would change from tasting them in the morning to tasting them again later in the day. Sometimes it was a different beer altogether.
Either double fist your order and set it aside as the second beer, or cup it like a fiend and breathe deeply and hork up those smells and warm it like you would your hands on a cold day while it comes up to the right temperature. BA beers really are shy at pour temperature and I think they are basically a waste of money if they get consumed at anything below 55f. Your patience will be rewarded with them.
They can pick up anywhere from a mild 1 - onwards of 3 and 4% and possibly more in the abv depending on the barrel and more importantly how fresh it is coming from the distillery.

 

I always wondered why Foothills ba people's Porter is so low. This site actually lists the ba version with a lower abv than non ba.

 

At room temperature and normal pressure for an alcohol-water solution, the vapor phase concentration of alcohol willl always be greater than the liquid phase concentration of alcohol (until about 95% alcohol). This means that you cannot increase alcohol concentration in the liquid beverage through evaporation (i.e. "Evaporation of water from the beer..." to increase alcohol content is physically impossible). The result would always be the opposite.

 

That's easy - every barrel is a living organism and what it chooses to do with the beer is completely up to it's own damn preference.

 

Probably not exactly the same brew as the regular BCBS.

 

Hmm.. This base on what? As far as I know, "Evaporation" of alcohol from the beer occur more easily? Or am I wrong?

 

Humidity makes a huge differnce. When you are talking bourbon, high humidity will decrease the alcohol and low humidity will increase the alcohol. I would imagine the same would be true for beer.

 

Many things in this world prefer to exist in a state of equilibrium, wood is no exception. When you are barrel aging in spent spirit barrels there is a constant exchange of liquid. The wood will release the spirits and take in beer. As you replace the less alcoholic beer for more alcoholic liquor you will undoubtedly see an increase in abv in the beer.

 

Fun fact: the evaporated beer is called the Angel's Share.