Some visuals from Brewday

[Bryan R]

I made an export helles today.


I used 50mgl dosage and this is the strike water before dough in.


Here is after dough in 10 minutes into the mash:


Here is preboil:


So as you can see, once you get your processes down, you can lower your SMb rate quite substantially. It looks as if my system and methods consume roughly 25mgl. My goal(as should everyone elses) should always be to use as little of the "crutch" as possible.

[Big Monk]

I entered a drop down in my brewing spreadsheet that changes the Na, SO4 and pH alterations based on SMB dose. I'll try to hone in on the actual numbers soon but for now just took the 100 mg/l base dose rate and divided 24 Na, 75 SO4 and 0.1 pH by the reduced dose rate. Not full proof but at least it's coded in there so when some more concrete numbers are around I can punch them in.

[Techbrau]

One important thing to keep in mind (lest people think that you can get away with 25 mgl) is that the less sulfite you have in concentration, the slower its scavenging rate (since oxidizers are less likely to randomly collide with a sulfite molecule). So there's a balance we're trying to strike between using as little as possible and using enough to make sure the sulfite reacts with the oxidizers before they can damage the malt compounds.

I've also been having good results with 50-60 mg/l SMB (38-45 ppm sulfur compounds) on a tight system. Pre boil I'm also at about 25 ppm; Post boil, I have a bit less than that (15-20 ppm)

[Brandon]

[Bryan R]

Right, exactly it's a fine line. 1 oops is going to cause you a big problem, when you walk the razors edge.

[Big Monk]

What has been everyone's most important point of O2 mitigation?

[Bryan R]

I think preboil goes without saying. Then I would say underletting, then mash cap. You gotta try really hard to mess up a beer hot side if you have those nailed.

[Techbrau]

I am reluctant to provide a ranking, because among the biggest factors the weakest link dominates. Preboil doesn't work without SMB (and vice versa), if you drop the ball and pick up oxygen post ferment it's all for nothing, etc...but here goes:

1) Preboil + SMB. You need both; one won't work without the other. Adding a mash cap and doing other things to tighten up your system and reduce air exposure will allow you to go from a large SMB dose (like 100 mg/l) to a smaller dose (like 50 mg/l). Gentle handling, no splashing, etc. goes without saying.

2) Gentle, short boil and heat stress minimization

3) Spunding in the keg (+ cold ferment). This is assuming you're currently doing what many people do and fermenting at 10c, kegging with decent oxygen control (like using the fill with degassed sanitizer and push out with co2 method), and force carbonating. If your cold side methods are weaker than that, then this would take the number 1) spot.

There are a lot of finer points (like leaving your keg tap/gas lines disconnected when not serving - they're only slightly oxygen permeable but a month is a long time), but these are the big ones. If I mess up any one of the above 3 points, the beer goes down the kitchen sink.

[Big Monk]