Brewing up Joseph and Peter's #1 English Porter

A little while back, I made up my own porter recipe for a 2 gallon test batch: Joseph and Peter's #1 English Porter. Last weekend I finally got a chance to try it out.  Along with fellow brewer Mark and good buddy Jesse, we spent the day brewing up this fine batch of what we hope will be a dark, malty, low-abv porter.

The most important step in brewing homebrew beer is cleaning and sanitizing.
You can screw everything up, but as long as it's clean and sanitized,
you're going to end up with something drinkable.

All the ingredients, lined up:  2-Row pale malt, Briess caramel malt,
chocolate malt,  Centennial and Willamette hops.  Yeast not pictured.

Our recipe today differed slightly from the one on the recipe page.  We left out the wheat malt, and upped to .75lb of the caramel and .25 of the chocolate malt to make up the difference.

Sweet, sweet malted grains.

Heating the water for mashing.  It felt odd to be using such a
small amount of hot liquor (that's the water, for you new brewers)
in this step.  I'm so used to using more for our bigger batches.

Mark, drinking  a beer and keeping an eye on our mash.

It smells awesome: super sweet with really strong chocolate aroma.

Jesse watching as we sparge the wort into the kettle.

Finally, after an hour of boiling, we chill the wort before
transferring it into the carboy and adding the yeast.

We finished up with 2.5 gallons of wort at 1.040 OG, right on the money.  Hopefully this turns out well.  I'm really looking forward to trying it.

Hot Side Aeration and Stale Beer

I joined buddies Mark and Rob over at third buddy Drew’s house for a brewing session this weekend.  Drew siphons his wort into the primary fermenter after a turn with the wort chiller, which differs from the process Mark and I use; we like to pour the cooled beer through a screen and into a funnel stuck in the carboy to remove the solids (mostly hop pellet pieces).  However, this brought up some discussion of Hot Side Aeration.  Embarrassingly, I had not really heard of Hot Side Aeration before.  Mark and Drew knew it was “bad” but that was about it.

Basically, Hot Side Aeration is oxidation that occurs before the wort is chilled, during mashing, lautering, recirculating wort, etc., due to splashing, roughly stirring, air leaks in hoses...you get the picture.  Basically, introducing air to the wort when it’s hot.  It contributes to the finish product becoming stale, with cardboard flavors, more quickly.

Here’s the problem, though, and what got us we discussed it at Drew’s place:  Yeast needs oxygen in the wort to do its thing.  Enzymes become oxidized by introduction of oxygen into the wort.

WHAT DO?

Right, so we didn’t have an answer.  It piqued my curiosity, though, and I jumped online to read up on it.  Among a lot of posts extoling the evils of Hot Side Aeration, I found one that disagreed, and linked to an episode of BrewStrong in which Dr. Charlie Bamforth, Professor of Bewing Science at UC Davis discussed Hot Side Aeration, and its impact on beer quality.  The interview was, quite frankly, very entertaining and informative.  It’s linked here, so you can go listen for yourself, but the basic idea Dr. Bamforth presented was this:  Don’t worry too much about it.

Dr. Bamforth spoke of how the blame for oxidation has been pushed all the way back to the malt in general discourse, to the point where attempts have been made to breed grain that less likely to contain enymes that can become oxidized in the process of brewing.  Combine that with an almost paranoid need to prevent any kind of oxygenation in the wort during the whole process, and you’ve got a wildly complicated - and very expensive - setup to reduce stale beer in the finished product.  The problem, though, is that according to Dr. Bamforth, it doesn’t really seem to be making much of a difference.

Bamforth argues that there are too many places prior to fermenting that oxidation can occur, and tons of chances for different enzymes to bind with the oxygen during the process - too many for homebrewers, or even commercial brewers, to be able to reliably remove all of them.  It’s naieve to think that controlling one type of enxyme oxidation will remove the oxidation completely from the finished product, and it’s likely a moot point anyway.  

“There’s a lot of things that happens downstream of the brew house, and probably the most important thing that happens is you put some yeast it, and that’s a hell of a good way to clean up stale flavors,” says Bamforth.

So, even if oxidation is occurring in the mashing process, the likelihood of it being an issue is very small, because the yeast just takes the oxidized material, treats it like oxygen, and converts it to alcohol.  Bamforth uses an example: you could flow stale beer into an immobilized column of active yeast, and the yeast would actually freshen up the beer by removing the oxidation that had occurred.

“Everyone agrees lower the oxygen level in the bottle,” says Bamforth.  But he argues the time and effort is better spent in controlling the bottling and storage of the finished product than in struggling to reduce oxidation before fermentation.  Bamforth brings up Arrhenius, the swedish chemist who in 1889 was able to prove that a chemical reactions speed doubles with every 10 degree Celsius increase in temperature.  As a chemical reaction, oxidation in finished beer follows this rule.  For example, a beer that would stale over three months time at 70 degress Fahrenheit becomes stale in half that time at 85 F, or in a matter of a week or so if left in your garage in the summer at 100 F.  Conversely, if said beer was stored cool at 50 F, it would stay fresh for six months, and for more than a year at 40 F.

“At the end of the day, I think the acid test is: 'What is generic that you can do to slow down these reactions in the finished beer?' Oxygen level as low as possible and keep the finished beer as cold as possible.”  

The takeaway from all this is to be careful while brewing, but don’t stress too much about oxidation prior to fermentation.  A healthy pitch of yeast and strong fermentation, followed by concentration on good packing, reducing oxygen in the bottle and keeping the beer cool will do much more for preventing stale beer than anything else you could be doing for your beer.