Low Oxygen Brewing : Strike Water

I have always wondered if low O2 exposure pre-boil is just as important as low O2 post-fermentation... All the commercial breweries take extraordinary steps to reduce O2 exposure prior and during mashing, so does this really matter on the homebrew level? I don't know but I thought I would slowly start to implement some steps to see if my end result beers gets better over time. Alternatively, I may do some split-batch exbeeriments and a side by side on the same batch using different methods of O2 exposure.

Brulosophy did an exbeeriment on LoDo brewing and found it to produce a less desirable beer, likely due to the added sulphites yielding an "eggy" sulphur note.

Most of the information comes from the website The Modern Brewhouse. Regarding dissolved oxygen (DO), the author states:

It’s important to note that controlling DO levels in your wort and finished beer is crucial for preserving flavors and aromas developed throughout the brewing process. The “lingering” fresh malt flavors present in beers produced using modern brewing techniques are the result of this attention to eliminating hot side and cold side oxidation. Controlling DO levels during the mash will preserve the fresh malt flavors inherent in the grains themselves by guarding them against oxidation. Whether these flavors persist after the mash and into the finished beer will be determined by how well you control DO after the mashing process. This is why controlling the boil and controlling the DO levels during the cold side processes are also vitally important.

As a side note, many in the homebrew world think this is entering into crazy town and really is overkill for the 5 gallon batch. Anyway, here are some of the major areas the website evaluates for home brewers for pre-fermentation low DO methods. I will try to comment on each of these over the next few posts:

1. Brewing Water

2. Grain Crushing

3. Mashing / Lauter

4. Boiling

Brewing Water

This area of the website kinda goes way out into the fringes but I will try to simplify it as best I can. The main areas of concern are:

1. Use distilled or R.O. water for best results

2. Suitable mineral profile for beer style

3. Enough calcium for yeast health and flocculation (40-50ppm)

4. Control mash pH / Eliminate Chlorine/Chloramine from brewing water (Campden)

5. Eliminate DO from brewing water and protect against oxidation

Strike Water :

The basic idea of pre-boiling the strike water is to eliminate as much DO as possible before adding the grains. Just like cutting an apple and exposing it to air will rapidly oxidize it and turn it brown, the same idea applies to exposing crushed grains to oxygen. They will stale quickly. So if can eliminate O2 while the grains are mashing, we will preserve the freshness of the grains, yielding in a better final beer. Does this actually matter on a homebrew scale? Who knows...

Deoxygenating the strike water involves a few techniques, some more difficult than others. Pre-Boil is the first method. This involves eliminating most or all of the DO from the strike water. This can be accomplished by 1) bringing the strike water to a vigorous boil for 5 minutes, 2) adding MetaBisulphite (around 0.3g for a 5g batch) at 200F, 3) cooling to desired strike temp then finally 4) dough-in within 2-3 hours.

Recently I brewed a Kolsch style beer (recipe) using pre-boiled strike water (see image). However, I did not add meta-bisulphite (didn't have any on hand) or dough in within 2-3 hours as recommended above. Basically I boiled the water in the evening before going to bed for 5 minutes, then set my system to the mash in temp of 152F. Next morning the water was holding at strike temp and ready to start mashing.

In the future I plan to pre-boil the water the evening before brewing then mash in before going to sleep once it cools to the strike temp. This would basically be an overnight mash with pre-boiled water.

While I have no idea whether or not pre-boiling the water had an effect on the final beer, I would say the grains do taste "fresh" in this batch and it cleared up brilliantly and is a delicious end result! Who knows, maybe the voo doo really works.....