The Beer Thread

[33anda3rd]

The carbon in ethanol/alcohol is why. It can't bond with hydrogen. So it evaporates faster.

[33anda3rd]

Anything aged is gonna cost more because of time. It's time in tanks that sometimes you can push through countless ales. It's time in barrels that occupies the brewer's attention. Ales are fast, you can sell more beer. Hoppy ales are easy, you can cover up a lot of mistakes and sometimes off flavors by hopping the hell out if a beer. That's why we have a glut of hoppy ales. They're easy for startups to bang out and have a big margin of error.

Consider that ATG Brett beer. 10 days or so of ale fermentation plus 4.5 months of Brett fermentation. In 155 days you can ferment roughly 15 batches of an APA or IPA or DIPA, pushing out a few pallets of 12oz bottles every couple weeks, keeping a steady flow of beer on the market. Certainly there's a premium on the Brett beer that stops you from pushing out 15X more of another beer.

[33anda3rd]

Up until I read your post, I thought sour = rotten.

In a way, that's true. Brettanomyces and Lactobacillus flavors are completely undesirable in a lager or a traditional ale. They make your beer taste "rotten", un-fresh, spoiled and off in flavor.

In a Gueuze or other type of Lambic, Berliner Weisse, etc. those flavors, and also the flavors that come from a natural/wild fermentation are highly desirable and what kind of sour/wild flavor those yeasts impart are what people who love those beers look for.

[haltz]

At 70% humidity alcohol and water evaporate at the same rate, so you're just losing volume. That's the average humidity in St. Louis. In a barrel in Kentucky your abv will climb. In France it will lower. You're more of a beer guy than me. In a year it would seem fairly negligible regardless. Tell me what I'm missing here.

The vapor pressure of water is nearly twice that of ethanol so is that true?

I think so. This isn't great source material, just a quick google. I have a few books I can look while I'm at work tonight.

As a general rule of thumb, the hotter the ambient temperature is, the faster a whisky ages and the more it loses to the angel's share. The ambient humidity determines whether the loss is more water or more alcohol.

http://www.popsci.com/glenfiddich/angelsshare

In fact, during barrel aging in our cellar the alcohol level of the wine increases by up to 1.2%-1.5% over two years.

http://www.winemakernotesblog.com/2012/ ... evels.html

[haltz]

This might also have to do with the type of oak and the size of the pores. Ethanol is a much larger molecule than water so it has a harder time escaping the barrel. Having a hard time finding technical sources.

[jim]

Up until I read your post, I thought sour = rotten.

In a way, that's true. Brettanomyces and Lactobacillus flavors are completely undesirable in a lager or a traditional ale. They make your beer taste "rotten", un-fresh, spoiled and off in flavor.

In a Gueuze or other type of Lambic, Berliner Weisse, etc. those flavors, and also the flavors that come from a natural/wild fermentation are highly desirable and what kind of sour/wild flavor those yeasts impart are what people who love those beers look for.

I don't understand what you are saying.

[33anda3rd]

Water is H-OH. It's molecules bond with other water molecules easily, and as a result they create large tangled bonded webs of molecules. Those webs are strong and stick together. Ethanol is CH3-CH2-OH, and they can bond with other hydrogens because of the OH but because all of the carbon present in there cannot hydrogen bond they can't bond like water. They form weaker smaller webs and evaporate faster.

[Freed Roger]

Any interest I ever had in home brewing as a means to get into craft beer dream jobs, I lost years ago when I saw how much work (and science was involved). Instead I decided to focus on consuming.

Carry on my good friends in the beer making business. Keep doing God's good work.

[jim]

So how did they make good beer 500 years ago when the periodic table consisted of Fire, Water and Rocks?

[haltz]

Ethanol analyses by gas chromatography were performed on the wine initially (12.95 volume) and on 20 barrel composites at the end of the 50-week experiment. The final levels were 12.74% in the cave (a drop of 0.21) and 13.06% in the chai (a gain of 0.11).
(...)
The above data implies that the relative humidity balance point at which a table wine doesn't change in ethanol concentration due to evaporation is greater than 74%, the overall mean for the relative humidity in the chai.

Atmometry showed that migration of wine through wood is slow compared to evaporation. The relative humidity balance point at which wine does not change in ethanol content appears to be greater than 74%. Above this balance point, ethanol concentration will decrease with time, while below the balance point, the concentration will increase.

While barrel storage under dry conditions has the undesirable effect (especially if near 14%) of raising the ethanol concentration, it provides the benefit of concentrating aromas and flavors somewhat. Barrel storage under high humidity conditions, however, allows fruit to be picked later with riper flavors; the resulting, higher alcohol wines will then lose some of the alcohol during storage.

http://www.practicalwinery.com/janfeb91/wineevap.htm

In Europe, where wine is aged underground under humid conditions, alcohol content goes down with aging. In the US, where wine is aged in dry, refrigerated conditions, alcohol goes up with aging.

https://www.homebrewersassociation.org/ ... pic=6100.0

OK, last post. I'm pretty convinced that I'm right about this.

Think about it like this: it's really about how fast the water evaporates due to humidity. At 100% humidity the air is "full" and you'll see condensation. At 0% humidity the air is "empty" and you'll see rapid evaporation of water. This affects the ratio of alcohol by volume and your breakeven point is somewhere between 65-75%. Given that most beer isn't aged for that long, even in humid conditions (which you don't want unless they specifically help brett fermentation) you aren't going to see an appreciable change in abv.