Extech DO Meter, a million questions

[Brody]

So I finally have an Extech DO meter, I wanted to make sure I have everything straight:

Unboxing & Proper Usage:

After pulling everything out, I added the solution into the membrane, and fired up the meter. The instructions indicated their may be a polarization period (I have no idea what this means...) but since there was no astrick in the corner I suppose I'm good?

Calibration seemed too easy. All I did was dampen the cap, screw it on, turn the meter on, wait for the reading to stablize, and hold down cal/recall... is it really that easy? It sounds like you can calibrate with a zero-02 solution for improved accuracy. Is this a best practice?

From what I understand I don't have to worry about things like temperature or carbonation when taking a reading. I could take a reading at mash temps?

For storage, is it as simple as rinsing the probe, drying with a soft cloth, and putting the cap on? No storage solution pH meter style?


I'm excited to get rolling with measurements!

I had a few brews around to try:
1) My buddies bottle conditioned beer: 0.07ppm
2) Another buddies kegged beer (no spunding): 0.39ppm
3) A helles I have lagering: 0.19ppm (after the measurement seemingly stabilized it dropped to .17 then started rising up, is this 02 dissolving from air?)

Has anyone taken a lot of measurements at dough in?

As I understand it, I want to get my strike water as low as possible (I've been using the yeast scavenge method) but then dough in will typically add 1-2ppm... then the atmosphere will add another 1-2ppm... but this is ok as the SMS will prevent damage?

My hope is to identify weak points in my system (presumably my dough in and BIAB lauter) and see how they stack up to others.

[Brody]

Just caught the 122f in the manual as the upper operating limit

[Brandon]

[Brody]

Testing it out tonight I boiled a quart of water, pulled a little sample in a flight glass, cooled it in a water bath pretty quick, then took a reading. It was like 1.8ppm. Wondering if either my meters off, the pre-boil method doesn't work as great as the yeast method (based on Bilsch's #'s, I'm testing it in a quart now myself), or the tiny glass is letting in a lot of o2 from the air.

[Brandon]

[Brody]

Yea, even if I don't trust the precision I'm getting a lower reading after an hour with bread yeast + sugar in my 1qt samples than I did with the boil and chill so I think I'll leave that as my standard process (easier for me as well).

I'm wondering if the zero02 calibration solution they mention in the instructions will provide more accuracy. The warning about it messing up the probe though has me wondering. I'll probably try calling support tomorrow and pick their brains.

[Big Monk]

I'm going to stick with sulfite strips.

That seems like the cheapest way to know a rough approximation of your systems "tightness".

We have the advantage of the LI having done the major work for us.

[Bryan R]

Tech did the zero cal, and FWIW it maybe gained him .01 over standard cal. I put money on you adding air to the preboil sample while cooling. It only takes a shotglass full of air in a 5g batch to put levels above where you need to be.

On your 3 samples .

1 Is on the money on what I see in my bottle spunded beers ( great readings), long lasting freshness there ( to bad he lost all of that in that mash though).
2. Your buddy would have lost his lingering malt in a week or 2
3. You are right on the edge of losing flavor.


Good luck

[Brody]

[Brody]

Well, the sugar, water, yeast solution indeed measured even lower after an overnight (Bilsch's findings as well I believe). I'm loving this method since I can setup my water the night before, wake up, and roll.

I'm getting ready to undertake a lot of brewing. A friend and I plan on gathering up all our kegs and brewing 100 liters of Helles for an Oktoberfest party called "A Hundred Liters of Hell" haha. Looking forward to using the opportunity to audit my process.