We are at quite a disadvantage compared to commercial brewing for many reasons, however maybe the largest is simply surface area. If you compare the surface areas of these large macro breweries to us its quite ridiculous. However we can still contend, we have NaMeta, and we can limit our surface areas as well and it doesn’t have to be hard or expensive!
The dosage of NaMeta we advocate is system dependent, as every system is different, just like snowflakes. However, the highest dosage offers enough protection for basically not doing anything to mitigate surface oxygen intrusion. If you want to lower your dose of NaMeta (which should always be the goal), you can start by implementing equipment changes that offer limiting of surface exposure.
Amazon, which is pretty much the most amazing thing ever created, has many solutions for us. For brewers using round kettles and coolers, or square coolers, we have the availability to get stainless steel cake pans and cookie sheets for pretty cheap! The awesome benefit, besides the price, is that they float, so they can offer protection at any liquid level. Just find the size that works for you (double up if you have to for you square cooler guys).
In my setup I have 3 round cake pans, and I use them like this:
HLT: In the hlt I always leave the cap on, it will come to a boil faster, and then when I dose my water after preboil with SMB, it will protect from surface intrusion
BK: I use this lid to lauter from the MT, come to a boil, and later in the cooling process
MLT: I use this lid to place on top of milled grain, and for strike water transfer.
Here are some photos of the caps in action:
Here are some photos of Derek’s Mash Cap and Lauter Cap (non-floating cover that limits O2 exposure during lautering):
So as easy as it is to order from amazon, it really has some great benefits. These caps along with other low oxygen brewing practices has my sulfite consumption down to 10 ppm. I don’t see me ever not using NaMeta, but I am only dosing my whole brew now with 20 ppm. The goal should always be the least amount as possible. Good luck!