Concentrated or unfermentable?

[Wort_fish]

My partner and I hadn't brewed in a long time and apparently forgot the basics :/. Due to a more vigorous boil and using whole hops(a new venture) we were a gallon short after the boil. The recipe(pale ale) called for 1.050 and we had a reading of 1.060. Why didn't we add water at this point?! I wish I had a good answer... At the seconday dryhop, it was 1.027.A week later(more volume loss...) it was down to 3.125 gals at 1.030.

Phew, sorry for the long intro, my questions are:

1:how can you tell if your brew is short on water or if it's full of unfermentable sugars?

2:if you decide to add water before bottling, how can you calculate ABV?

3:is there a general rule of thumb for dry whole hop absorption?

Thanks in advance

 

[ImNoExpert]

Do a forced fermentation. Take a sample and put it into a 20oz soda bottle and dump some fresh yeast into it (any will do) and stick it in a warm spot with an airlock or some sanitized foil on it. If it ferments more then you still have fermentable sugars. If not, it's not going to ferment more and it's done.

 

[Wort_fish]

This batch is already bottled. More so curious for next time. I must have fermented what sugar was there because my gravity was no longer dropping(right?)

Here's my line of thinking:

I have lost much more volume than I expected. If I were to have added water than my overall specific gravity would drop. I would have been ok with that if I knew that my beer was "concentrated." However, I am not a fan of adding water it my sugars were correct and the beer is good as is(don't want to dilute it).

 

[Wort_fish]

Batch after batch never finishes as low as the recipe predicts for me ever since I started using more volume in a keggle. I think I'm scorching some grain resulting in unfermentables...

 

[ImNoExpert]

What temp do you mash at? Do you use malt extract or any less or unfermentable malts or ingredients? Are you pitching enough yeast? Are your yeast healthy? Is your wort properly oxygenated? What temps are you fermenting at?

A lot can go into explaining poor attenuation.

Also, it could be a measurement error. Are you using a hydrometer or refractometer for measuring gravity?

 

[Wort_fish]

BIAB. Mashed at 152 with a constant vorlof(to try and maintain temp through the batch as much as possible). but with keggle it never keeps temp so we ended up turning on the burner twice(this where I think the problem is) squeeze the bag. Plenty of yeast, purchased two days prior. It goes through a counter flow splashing into glass carboy and then we pitch and vigorously shake carboy(doing enough for oxygen?) fermented at 73 which I believe was within range, I'd have to double check. Measurements done with refractometer.

 

[Wort_fish]

I have purchased a rims tube and 90% of the other parts, just waiting on a buddy to wire it up. I am hoping that my issue is: I'm mashing at higher temps than I think I am, therefore extracting unfermentables. I never have an off flavor persay, just alcohol is lacking. To me it seems there's more body too, but that could all be in my head because I have convinced myself that's the problem.

 

[Yooper]

Measurements done with refractometer.

That's why! Once fermentation starts, and alcohol is in the mix, the refractometer reading is not accurate since alcohol skews the refraction of light (which is what a refractometer measures).

You can plug in your numbers in a calculator that can come close to guestimating the actual FG (http://seanterrill.com/2012/01/06/refractometer-calculator/) if you know your wort correction factor, but for many of us it's just easier and more accurate to use a hydrometer once fermentation starts.

 

[Wort_fish]

Thanks Yooper! I wasn't aware that a refractometer post-boil was ill-advised. Luckily I have a hydrometer still and will be going back to that in the fermentation. [emoji482]

 

[Wort_fish]

Any quick guesses on how far off a refractometer will be at FG? (@6%ABV)

 

[Wort_fish]

If your beer has dropped in gravity as the recipe predicts, and you're short on volume, then your beer is concentrated?

 

[Yooper]

Any quick guesses on how far off a refractometer will be at FG? (@6%ABV)

You can use the refractometer post-boil! It's just not accurate post-fermentation, without using a calculator, and even then it's not always 100% accurate.

You'd have to plug your pre- and post- fermentation brix readings into this calculator (no one can possibly guess), and you can use 1.040 as the wort correction factor, until you know what yours is: http://seanterrill.com/2012/01/06/refractometer-calculator/

 

[ImNoExpert]

If your beer has dropped in gravity as the recipe predicts, and you're short on volume, then your beer is concentrated?

I'm not sure if concentrated is the right term. If you ended up with more sugars in your OG wort, you'd get more alcohol in the FG beer. But as OG goes up, hop utilization goes down. So it's not simply concentrated, it's just a little different.

If volume is really that important to you, then you could dilute it with some sterile, deoxygenated water. Were it me, I'd probably just bottle it and drink as is. I'd simply make a note for next time to either add more water pre-boil or sparge longer (I run a three vessel and fly sparge).

You may consider picking up Beersmith or some other brewing software. It really helps with all these calculations.

 

[Wort_fish]

I did opt to bottle as is even though I ended up with only 3 gals.

Let's say for example recipe is 1.050 down to 1.010

And I get 1.060 down to 1.030 with more volume loss than normal.

We have established that my FG number is likely off because of the refractometer use, but if those numbers were correct...

I don't know of a way to tell if I have underperforming fermentation or higher specific gravity due to volume loss.

Am I looking at this the wrong way?

Not trying to be annoying, just want to fully grasp this concept.

 

[Yooper]

I did opt to bottle as is even though I ended up with only 3 gals.

Let's say for example recipe is 1.050 down to 1.010

And I get 1.060 down to 1.030 with more volume loss than normal.

We have established that my FG number is likely off because of the refractometer use, but if those numbers were correct...

I don't know of a way to tell if I have underperforming fermentation or higher specific gravity due to volume loss.

Am I looking at this the wrong way?

Not trying to be annoying, just want to fully grasp this concept.

The higher OG is due to the concentration. That doesn't affect the FG, unless you boil it so hard you change the chemical make up of the wort, like a caramelization type of reaction. And even then, it wouldn't make the wort so unfermentation. Adding water to the wort would have kept your OG where desired, but wouldn't effect the FG.

And your numbers aren't correct for the FG so you don't have a stuck fermentation.

What does affect the FG are things like the ingredients (darker crystal malts and some yeast strains), and mash temp.