My beers stall consistently...?!

Are you correcting your refractometer readings with a refractometer calculator?

 

I love how often this is the answer.

 

how are you oxygenating your wort? I brewed 20 gallons a few weeks ago, split the batch to a 15 gal. keg and a 6 gall carboy. The carboy got US-05, where as the keg got Saflager S23. Both started at 1.083, after 3 weeks the carboy had stalled at 1.032 and the keg was sitting at 1.053. I kegged the carboy (judge me all you want) and added EC1118 to the lager after letting the temp come back up. the only factor that I have been able to figure is I have not been getting enough oxygen in the wort for a healthy fermentation. I checked all my readings with hydrometer and a refractometer. Both fermentation started out very strong. I am confident I do not have a yeast problem or a mash temp problem.

 

Seriously though...

You absolutely must use Part II of the following calculator or similar with a refractometer whenever alcohol is present, otherwise gravity will read high. And you must read in Brix and ignore the specific gravity scale inside the thing.

https://www.brewersfriend.com/refractometer-calculator/

So it looks to me like your FG is actually about 1.020 in all 3 cases.

Even 1.020 is still kind of high IMO. So then this makes me wonder.... are you using extract? Some extracts just aren't very fermentable. Try a different brand of extract, then the problem will likely just go away.

 

As I'm pretty sure you know, but @MarzipanAle may not, a calculator should also be used for the OG reading, which will otherwise also read high (though not nearly as severely as the FG) if not corrected, due to the differences in refractive index between the sugars and dextrins making up the wort and a plain sucrose solution, which wort is not.

That's my best run-on sentence for the day, and it's only 7:25.

 

/thread

 

More and more I'm finding that the average "Wort Correction Factor" is about 1.00. Mine here is nailed down at 0.99. Not far enough from 1.00 to make much impact.

 

For my beers, at least the ones I have measured both ways, the WCF tends to be between 1.03 and 1.04.

 

Okay. YMMV of course.

 

I have always known that Brix really reflects the combined refractive properties of the compounds in solution. Similarly, OG represents the combined density of the compounds in solution. But what calculation is done to tease apart the contributions of dextrins, sugar monomers, dimers, etc? What key pieces of data or assumptions come into play?

 

Super easy mistake to make, @MarzipanAle. The first time I used a refractometer I had a porter "finish" at like 1.035 and I lost my shit but luckily someone (can't remember who) steered me to a calculator.

 

OP states these are all-grain brews, not extracts

Since this is all-grain, I have a couple of questions:

- What is your grain bill for one of these?

- What temp are you mashing at, and for how long?

- Have you done an iodine test to ensure all of the starches have been fully converted?

- What pH is your mash at the 30 minute mark?

 

OP said “steeping” and not “mashing” he probably is doing extract with steeping grains. Regardless OP didn’t have an issue with OG so I don’t see how these questions matter that much...

 

Curious if you brew all-grain?

The OP said all-grain and made no mention of extracts or DME. Many people incorrectly use the word steeping when referring to the mashing process. Let's let to OP clarify instead of the snarky remarks, ok?

Mash temp impacts enzyme conversion of the starches into fermentable sugars.

Knowing the grain bill helps to understand what the anticipated OG should be, if the grains have enough 'enzyme power' to convert starches to fermentable sugars

The iodine test offers proof that the mash conversion is complete


Sooo outside of a snarky comment about meter readings, you have offered no help to the OP and their question about attenuation.

 

Thank you for the education.

 

More for the OP and others to consider:

Be sure to re-zero your refractometer in plain water with every use. Mine varies widely within plus or minus 0.4 Brix from zero with every use. The thing just does not hold calibration well at all.

Also, check calibration of the thermometer you use for mashing in both boiling and freezing water. If the mash temp is way off, this could affect attenuation somewhat.

Finally, which yeast strains have you used? Some yeasts don't attenuate well at all.

 

Well, nailing the Wort Correction Factor (WCF) for each and every batch would be like finding the Holy Grail. And to my knowledge, nobody has done it. There are four approaches I can think of. I'll list them in what I consider to be a (roughly) ascending order of chance for success.

- Use the calculator's default WCF. Typically (I think), the calculator's author provides some sort of default WCF that has, in the author's experience (or something he read on the internet), best matched his results across the recipes that the author tends to brew. Sean Terrill, for example, gathered a bunch of data to determine his default WCF. Then he gathered some more and tweaked his default.

- Use your own (user's) default WCF. Similar to the calculator's default WCF, but based on the user's "typical" experience. (I don't know if there are still any calculators that don't allow you to change the WCF, but if there are, I would avoid them.)

- Use a better estimated WCF, based on wort characteristics. If you could know the precise makeup of the wort, this would be the Holy Grail I mentioned. However, nobody ever knows the precise makeup of their wort (or for that matter developed a calculator to use it). Given this conundrum, for BrewCipher I made a formula that uses expected wort attenuability as a proxy for proportions of simple sugars/complex sugars/dextrins. It avoids having to know the precise makeup of the wort, and provides a recommended WCF that seems to work pretty well in general, at least for my batches and from what some users have told me. (Nobody has told me they suck, so there's that.) Of course, the recommended WCF can be overridden by the user. Which brings us to...

- Determine the actual WCF for each batch, by measuring OG with both a refractometer and a hydrometer. This would seem to defeat the purpose of having a refractometer, but it can be useful for two reasons. 1) Data gathering. 2) If you do this with OG (where a sanitary sample can be returned to the main wort) to determine the actual WCF, then you can use just a corrected refractometer reading (a drop vs several ounces) for FG. This approach is quite convenient in some setups, including mine. After taking refractometer and hydrometer readings of the OG, you can pop the refractometer reading into the calculator, then tweak the WCF until the resulting OG gravity matches what the hydrometer said. Now you have a WCF tailored for that batch, and the FG refractometer reading can later be used without another hydrometer reading (and wasteful sample).