AG never finish attenuating

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elgee

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I am at my wits end here. Every AG batch I make, stout, IPA, pilsner, etc never ferments below 1.020. I’ve read all the posts I can find and I don’t know what it can be? I wonder if my pH is causing the beer to never ferment out, although I don’t think it’s that bad, 6.3 is my water pH. I even mash on the low end. Hydrometer is calibrated and I’ve tried all temp variations, but nothing gets me lower. Can’t figure it out?
 
Sure. IPA recipe.
11 lbs 2 row
8 oz c40
8 oz white wheat malt
8 oz Carapils
Centennial - 1 oz 45 mins
Amarillo - 1 oz 20 mins
Simcoe - 1 oz 20 mins
1 oz each at flameout for whirlpool
yeast: us-05
Water:
Chloride 170
Magnesium - 7.2
Sulfate 0
Total alkalinity - 90
Biocarbonate - 109.8
Total hardness - 80
Sodium - 116.38
Sulfuric Acid 110
Residual Alkalinity
Hardness - 90
Calcium Hardness 50
Ph: 6.3
Ferment temp: 68 raised to 72 after a week
OG: 1.062
FG: 1.020
 
I mashed at 148 did a mash out at 168. Water report is from the Lamott Brewlab water test kit they sell at Morebeer. I use an Ss Brewtech unitank with the temp controller and a glycol chiller.
 
Last edited:
Might be obvious but you didn't mention how much yeast you pitch, and do you aerate at all?
 
Water:
Chloride 170
Magnesium - 7.2
Sulfate 0
Total alkalinity - 90
Biocarbonate - 109.8
Total hardness - 80
Sodium - 116.38
Sulfuric Acid 110


i'm not sure, but i had horbile luck using water calcs with a meter...have just fine luck i don't even adjust ph now...

and.....
sulphuric acid? 110? what did whatever calc you used tell you? 🤔

i mean i've used drain opener to make jam before, damn good...but never seen it used for beer?
 
You were asked how much yeast you pitched and how much you usually pitch, but your reply simply states " US-05 ". The brew mentioned in your original post had an OG of 1.062. I would add 2 sachets for anything between 1.060 and 1.070. Although 1 might be enough, there is no knowing how that might affect your beer, unless you are either lucky, or have trouble identifying off-flavours.

If none of your brews ferment below 1.020, you have to start checking every piece of equipment you are taking measurements with, including your thermometer. From what you are telling us, it could easily be a higher than expected mash temperature.
 
Are you using the same large (55 lbs bag) of base malt? It seems like temperature is the most likely explanation, but it's also possible one of your ingredients is causing an unexpected level of unfermentable sugar.
 
I order just the amount needed or from the kits from Northern Brewer or Morebeer. It’s odd, since moving a few years ago is when the issues started. Maybe the grainfather is the culprit and it’s not extracting the sugars needed from the mash or the boil is just not vigorous enough? I could go back to the cooler mash tub and propane to see if that fixes it? I do add corn sugar sometimes too, but still has no effect other than raising the OG.
 
I actually always see around 70-75% attenuation, regardless of the mashing process just recently I made a Belgian Blonde with an intense step mash of 30 minutes at 64°, 20 minutes at 67° and another 20 minutes at 72°. Finished at 74% attenuation, in spite of a small dose of sugar. The temperature is correct (or identically incorrect across several thermometers, which I find unlikely).

Quite possibly, my hydrometer is off, but again: I've had a couple of them (I'm clumsy, they break easily, what can you do) and it has been the same throughout. I've had it when I was mashing in a direct-fired pot, and I still have it on my grainfather.

And yes, I do treat my water. I've never actually measured my mash pH, though, relying on estimated values and municipal water reports.

Nonetheless, I call it a "phenomenon", not a problem, because the low attenuation is not reflected in the flavour. And it means less alcohol, which is a good thing in my book.
 
I order just the amount needed or from the kits from Northern Brewer or Morebeer. It’s odd, since moving a few years ago is when the issues started. Maybe the grainfather is the culprit and it’s not extracting the sugars needed from the mash or the boil is just not vigorous enough? I could go back to the cooler mash tub and propane to see if that fixes it? I do add corn sugar sometimes too, but still has no effect other than raising the OG.
Have you actually read the answers here? :D
 
I wonder if my pH is causing the beer to never ferment out, although I don’t think it’s that bad, 6.3 is my water pH
Water pH is much less important than mash pH.

It’s odd, since moving a few years ago is when the issues started.
It's possible that the mineral content of your current water is meaningfully different than it was previously.

Consider brewing a batch with using RO/distilled water, use either water chemistry software (or this article [link]) to target a proper mash pH, and measure mash pH.
 
I have thought about RO water for my next brew to see if that fixes it, if so, the brewlab kit is garbage!
 
I am at my wits end here. Every AG batch I make, stout, IPA, pilsner, etc never ferments below 1.020. I’ve read all the posts I can find and I don’t know what it can be? I wonder if my pH is causing the beer to never ferment out, although I don’t think it’s that bad, 6.3 is my water pH. I even mash on the low end. Hydrometer is calibrated and I’ve tried all temp variations, but nothing gets me lower. Can’t figure it out?
A few things you can check... check the date on your yeast, aerate with pure O2, some said not to use yeast nutrient... but keep using it. Rehydrate your yeast... some say don't, but do it. Check and double check your mash temps. Get a second thermometer to verify. If mashing below 150, give it an extra 15 to 30 min as beta amylase works a bit slower than alpha dominant conversion in the 150s and up. Pitch yeast at or very near your anticipated fermentation temp. Check your mash pH. Your 6.3 pH water is fine, but your mash pH should be roughly 5.2 to 5.7. 1 packet of US-05 in an ale when hydrated is more than fine when gravity is 1.060. Lager you'll definitely want 2... of any yeast. 05 is a high attenuator. It should chew down to 1.012 easily or even 1.009 from 1.060. If it's stalling, it likely didn't have adequate nutrition (unlikely since you added nutrient) or lack of O2, which inhibited budding and growth, meaning the cells that were there mostly died out. If aerating with air, use a sanitary filter and aerate for 30 min to get to 8 ppm. If you use pure O2, set regulator to 1/8 and stick wand down to the very bottom of the vessel and aerate for 60 seconds and you're set. Hope this helps!
 
sounds like you've tried a lot of things mentioned here that should of solved it, the thing that stands out to me is what's you final Ph? I would get some Ph strips so you can do a quick test after fermentation just to make sure.
Good luck.
 
My money is on your water/mash pH...148F mash, you should be finishing below 1.010. Pretty much every time I mash below 151, my beers finish between 1.005-1.008. Using US-05 isn't an issue, but I would still use a yeast calculator to make sure you are pitching enough cells.
 
my thought has been that the pH is off a bit for the mash. I’m going to recalibrate my pH meter.
 
I’ve been debating sending off to ward, but also considering getting a RO system in the brewery.
 
my thought has been that the pH is off a bit for the mash. I’m going to recalibrate my pH meter.

Your pH meter should be calibrated before every use.

What mash pH were you getting? When were you measuring it, and at what temperature?
 
That’s one of my biggest failures. I haven’t measured mash pH. I added 5.2 stabilizer but I don’t know how effective it is.
 
That’s one of my biggest failures. I haven’t measured mash pH. I added 5.2 stabilizer but I don’t know how effective it is.

You didn't mention above that you added 5.2 stabilizer. Is there anything else that you added?

I don't think it would affect attenuation, but I don't think that it helps unless by luck you happen to have the same specific water makeup and goals that it was designed for.
 
Nothing else added that I can think of, I think the logical next step is to just start from RO water and build the water profile from there and see if it’s really the water or something else.
 
Yeast nutrient is unnecessary for beer, it can really harm the flavour though so I'd skip it.

I bet it's the temperature, false readings from the thermometer.
Why do you say yeast nutrient can harm the flavor of the beer? I’ve always used the wyeast nutrient and never noticed any problems, but now you have me curious.
 
Why do you say yeast nutrient can harm the flavor of the beer? I’ve always used the wyeast nutrient and never noticed any problems, but now you have me curious.
Because it is extra stuff that has a taste that goes into the beer. I know of cases, where mysterious off-flavours were hunted and hunted and not found... until they ditched the yeast nutrient.

Malt is basically really rich in nutrients, and although beer yeasts are a bit of spoiled character, compared to not minding wine yeasts, they still have everything they need within the wort already present. A healthy pitch rate and fitting temperatures is everything that is needed.

One could argue that kveiks are a little exception, as they have eveolved within higher gravity wort, but from my own experiments, I must say that at least lutra performs very well in low gravity worts (1.03) without any extra nutrients. I had the same result with voss in "normal" gravity wort (around 1.05).

So the takeaway is: Do not use stuff in your beer that is unnecessary because it will somehow affect the flavour. if it is in there, it will be also in the flavour, maybe underneath the taste threshhold if you are lucky, but if unnecessary from the beginning, why take the risk?
 
From what you told us I don't see much that sticks out as a potential issue except for using pH 5.2, your thermometer, and your water.

Stop using pH 5.2 (it's snakeoil), and verify your thermometer is accurate by "calibrating it" in melting ice (32F) and boiling water (212F at sea level, adjust for your elevation)!
What thermometer is that?

It’s odd, since moving a few years ago is when the issues started.
And moving came with a different water source... That really seems to point to the issue.

Do your next batch with RO water and let us know.
 

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