Got my copy of Kunze today. Reminds me of my
old Morrison and Boyd Organic chemistry text in size and volume.
Look forward to reading it. Doesn’t seem too intimidating.
I’m confused on the water chemistry. Chemistry is not my strong suit. :( I added 50 mg/L of SMB (1.6 gm in 32 L) but my TDS meter jumped by 103 ???
Well 50ppm SMB (if my math is correct) would add ~ 38ppm sulfate and ~ 12ppm Na. That would definitely affect TDS.
Awesome. Chapters 3,4,5 is where I would start 
Yup and yup!
But it should have gone up by 50 or so not 103!
I think you just found the variance in your meter.
I recently got some Sulfite test strips thru Amazon. Checked the 2 beers I brewed with LO techniques. These were both Ales, EPA and APA using WY 1272. The EPA was a fly sparge with 100ppm in mash and 25ppm sparge. I checked the ph at 4.4 for both beers. After ph adjustment the EPA read around 5ppm after 4 weeks conditioning in the bottle. This doesn’t seem too high. I bottled this batch with Asorbic Acid so with the small amount of META it should be ok, does this sound right? I might mention the EPA was dryhopped in purged secondary. The APA is being bottled this weekend. This beer was my first no-sparge attempt. The Sufite was 63ppm for this batch.The Sulfite read 10ppm after fermentation was complete. Thinking of skipping the dryhop on this one. My thinking is most of or half of META will be used up at bottling. Thought I would report what I’ve seen with my system. Is my thinking right, should I reduce the META more? By the way both these smell and taste great,though the APA not as much aroma, really made the hops pop.
How much AA did you use? Been thinking of using the same
I would not use AA alone by itself its a known super oxidizer.
What’s wrong with page one?
Nothing. 3,4, and 5 are the meat of what this is all based off of though.
Yeah I seen the post with the highlight on not using AA alone after I bottled. I only used 1/2 tsp, the instructions said 1 tsp but I thought I would have some Sulfite left. I do have 5ppm or less in this batch with the AA. Maybe the Beerery will comment but I will stop using AA at package if I have any Sulfites left at that time.
I am not familiar with 1272 and its sulfur tolerance, or what it leaves residual. But I wouldn’t necessarily lower your SMB dose if you can’t taste it in the final product. The residual sulfites, will certainly help at packaging.
Variance in my TDS meter may be part of the problem but there may also be an error in the way Na and SO4 is calculated for a given SMB addition.
BIG DISCLAIMER: I am an (old) engineer and NOT a chemist. If the following is chemistry nonsense, please correct me…gently.
SMB is Na2 S2 O5 . While you are indeed adding 24 ppm Na and 76 ppm S and O for a 100 mg/L addition, there should be an additional TDS contribution for the O2 scavenged and that should add about 25% to the SO4 TDS. Therefore, 100 mg/L of SMB should net 24 ppm Na and 95 ppm SO4.
The 76 ppm SO4 is a result of fully exhausting the 100 ppm NaMeta dose. The scavenging IS what gives you the 76 ppm.
If you dosed with 100 ppm and didn’t pick up any Oxygen, you’d have no added SO4.
That’s my interpretation short of digging out my old Chem text.
Ha, Big Monk, I"ll bet my old Chem text (long lost) is older that yours.
But here’s the way I figure it. (see BIG DISCLAIMER above):
SMB is NA2 S2 O5
the atomic weight (rounded) is:
Na = 23 X 2 = 46
S = 32 X 2 = 64
O = 16 X 5 = 80
190
46/190 = .242 or 24% Na
(64 +80)/190 = .758 or 76% S and O
To fully oxidize all the S to SO4 you have to add 3 oxygen atoms with total AW of 48. And those atoms are not in the initial weight of SMB.
So, no, the 76 ppm is NOT “a result of fully exhausting the 100 ppm NaMeta dose”, it’s what is in the initial dose.
I just meant to say the potential for 76 ppm exists in a 100 ppm NaMeta dose. Hypothetically speaking, if you added zero oxygen during the brewing process, you wouldn’t get any SO4.
I’m just struggling I guess to justify how you would get any additional SO4 like you stated in your original post.
Philbrew is correct. 100mg/L of SMB add a theoretical amount of approximately 101 ppm of sulfate, assuming all MB is converted to sulfate. The calculation needs to be made based on S and assume that during a full conversion from SMB to sulfate MB will get the rest of the oxygen from the system.
Certainly some S will be lost to other reactions depending on one’s process, but the theoretical maximum amount that can get converted is 101 ppm not 76 ppm.
By measuring sulfate in the final beer one can calculate how much of the sulfur in the MB got converted to sulfate.
Cheers.