Before you read this article, take a deep breath.. aaand exhale. Feel better? Yes, oxygen does the body well!
It’s ironic that oxygen is one of the essential requirements of life yet also a bringer of destruction. We see the results of oxidation every day. Rust, mold, spoiled food, fire, and worst of all: stale beer.
A perishable product, beer will eventually lose its shine and become stale. Higher ABV will help fortify the flavors and extend shelf-life, but did you know that most of the stuff we brew at home and even many professionally brewed beers are “stale” before they even hit the bottle? In fact, oxidation and flavor loss occurs before we pitch the yeast!
Well, that’s what low oxygen brewing claims and attempts to address.
Low oxygen brewing is a process or set of techniques employed to minimize the amount of oxygen present throughout the brewing process.
The Germans have mastered the art and science of low oxygen brewing, which could be the reason why authentic German beers have that unmistakable and famously difficult to replicate malt flavor.
So, if you’re brewing German styles (or any malt-forward style for that matter) but can’t quite get the malt to taste right, LODO might just be the key.
What Is LODO?
Let me first say that I am in no way contributing to the LODO community here other than simply getting the word out to an awesome group of brewers. LODO is a very new and largely unexplored concept, and I hope to get more folks on board to help experiment and research.
Low Dissolved Oxygen (LODO) is a term coined by the guys at the German Brewing Forum (GBF) to describe a process for employing low oxygen brewing at the homebrew scale.
According to their original paper on LODO, “On Brewing Bavarian Helles: Adapting to Low Oxygen Brewing,” oxygen exposure in excess of 1ppm (parts per million) for more than 1 minute at any point during the hot side will result in an irreversible loss of malt flavor and aroma.
Sounds kinda crazy, right?
Heck, that strike water you heated to 170F is tainted with at least 4ppm oxygen. Throw those freshly milled grains on top of that, wait a minute, and voila! You’ve ruined the mash.
“But the mash smells so heavenly!” Yeah, that’s the smell of your precious malt flavor escaping! Every whiff of sweet malt is flavor that could have been in the finished product.
Sorry, being overdramatic humors me. You didn’t REALLY ruin the mash. You can make some pretty freaking fantastic beers without completely eliminating Hot Side Aeration (HSA). We’ve been doing it for years.
Is LODO loco?
If you’re skeptical at this point, you’re not alone. The HSA discussion has been around for years, and LODO is somewhat of a continuation.
There are several great threads out there with real discussions, useful information, and personal accounts from both points of view.
- Reddit: Exploring LODO
- BeerAdvocate: That special German malt flavor explained (?)
- Homebrewers Association: Introduction to Low Oxygen Brewing
I can’t give my own personal experience yet, so I am at the mercy of the Internet. From what I’ve read, it seems those in favor of LODO have provided more evidence that it actually works than the naysayers who say it doesn’t matter.
So, How Do You LODO?
I won’t go into much detail here, mainly because the information has already been painstakingly written by the guys at GBF and supplemented by several other fantastic articles that I will provide links to below.
Instead, I’ll hit some high points so you can get an idea of what to expect before delving into the more intense material.
Here’s the good news
Assuming you are an all-grain brewer, you don’t need to go out and purchase a bunch of fancy equipment.
You’ll want to avoid copper, brass, and aluminum equipment such as immersion chillers and plate chillers. These materials can cause or provide the means for accelerated oxidation of malts. Swap it out for stainless steel.
You might also consider purchasing a dissolved oxygen meter to pinpoint weak areas in your process and ensure consistency.
Here’s the not so good news
LODO brewing ain’t easy! It’s a lot of work. And you probably won’t get it right your first try.
You will have to rethink some of your practices, be much more careful with handling, and be prepared to add some time to your brew day.
Oxidation can occur at almost every point in the brewing process. From milling the grains all the way to packaging. And since oxidation can occur any time the DO levels reach more than 1ppm, you will need to make sure you pay attention to every single step.
That being said, the mash is where you want to focus your efforts in the beginning. The articles below will show you how, but basically, you want to boil off as much oxygen as possible from the strike water prior to dough-in, and avoid splashing.
You will also recruit the help of oxygen scavengers such as Sodium Metabisulfite (SMB, or NaMeta) or campden tablets. These little guys provide active protection against DO, but should not be solely relied upon to meet LODO requirements.
When boiling the wort, keep it at a nice simmer. Vigorously boiling causes heat stress, accelerating oxidation and dulling the beer.
This one is easy to overlook: chilling the wort. I personally use an immersion chiller and typically get a nice whirlpool going. While it greatly accelerates the temperature drop, swirling and splashing are great ways to introduce oxygen and ruin the progress you’ve made to this point.
Avoid strong movements at all costs!
Once you’ve cooled down to pitching temps and transferred to the fermenter, the yeast is your best defense against oxidation. Pitch the yeast first, then immediately aerate the wort with pure O2 from an oxygenation kit. The yeast will consume the oxygen and begin working their magic.
If you’re still reading, I’ll assume LODO has gotten your attention and you want to learn more.
- Here again is the link to the original LODO paper from the German Brewing Forum: On Brewing Bavarian Helles: Adapting to Low Oxygen Brewing
- Matt from Accidentalis Brewing wrote an applause-worthy article exploring the GBF paper and providing some insight from his own experience: Low Oxygen Brewing; Exploring LODO.
- LowOxygenBrewing.com is another great resource developed to walk you through the entire process: Methods of the Low Oxygen Brewhouse
- Winning-Homebrew.com posted a very easy to follow summary of all the LODO steps: Low Oxygen Brewing – Summarized for the Homebrewer.
Some are saying that LODO is the most exciting and intriguing brewing process experiment in recent years. There is still a lot of research and experimentation to be done, but results thus far have shown to be very positive.
So, if you’re looking for new ways to take your brewing setup and process to the next level and achieve malt glory like you’ve never experienced before, then try experimenting with LODO.
You could be the one to provide groundbreaking evidence on the effects of a brand new brewing technique that will propel our homebrew to new heights for generations to come!
One of the original LODO paper authors hinted at the idea of using an ultrasound device in the mash and boil to knock out dissolved gasses. The possibilities are endless!