Day 6 (and 7, oops)
Again I missed a day in this process, however, it’s no biggie. Exactly one thing happens on both days 6 and 7 - nothing. The beer looks like the day it began. The foam has dissipated because the fermentation is complete - the yeast is just seeking out a few last sugar molecules to eat and the rest of the CO2 is dissipating. During this whole week, of course, the barley and hops and yeast are continuing to meld flavors. Although the primary flavoring occurs when the malt and hops are boiled, it certainly doesn’t stop there.
Beer Chemistry
I can’t remember if I mentioned, but my dad is a biochemist. No, no kidding. So now is the fascination with the chemical process of beer-making becoming clearer?
My dad had a few lessons in beer chemistry to impart to me. I haven’t really seem much that was good about the chemistry on the web, so I’m going to try to share some of it here in hopes it will do someone some good.
Q: Why is beer bottled in brown and green bottles?
A: The darker green and brown bottles protect beer from UV light. Beer is a chemical process with the primary agent being yeast.
If you thrown in sunlight (i.e. UV radiation) then you create chemical processes that make products you really don’t want through photochemistry (i.e. chemistry caused by light). Primarily, light might burn the yeast and kill it. It can also create vinegar, or even worse, something toxic. (see below)
It’s really important to keep your beer away from things that can interfere with the brewing process. Store your brewing beer at room temperature, away from direct sunlight. And make sure to sterilize your equipment before you use it so that you don’t get bacteria or toxins in your beer that produce chemicals you don’t want!
Q: What chemicals does brewing produce?
A: Yeast (a single-celled animal) eats sugars (glucose) and secretes (yeah, I meant that) ethyl alcohol (also known as grain alcohol) and CO2 (carbonation).
Q: Is that all that yeast can produce?
A: No, different kinds of yeast can produce different alcohols - ethyl, or grain, alcohol is the only kind of alcohol you should ingest. As the name indicates, it’s derived from fermented grain. Yeast can also produce acetic acid, ethyl acetate and acetaldehyde.
Q: WTF are those last ones?
A1: Acetic acid is an acid - and when in a 2-3% solution (i.e. 2-3% acetic acid, 97-98% water) is known as vinegar.
A2: Ethyl acetate is what’s called an “ester” - and is a combination acid + alcohol. It’s toxic. It has no everyday name.
A3: Acetaldehyde has no common name either. It’s what’s called a “reduced acid.” You also really don’t want to drink this - toxic.
Ew! These do not go under Martha Stewart’s “Good Things” category. Good thing we’re brewing right, eh?
