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Charles Stanley-Grey

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Evening all,

I was gifted a home brew kit for Christmas by my lovely wife and made an almost....drinkable, but flat, wheat beer. Naturally, I am now hooked! I have purchased myself a 25L Klarstein brew kettle, a copper immersion chiller and all the extras needed for a basic BIAB set up.

I brewed a ‘proper’ wheat beer just over two weeks ago, with my new kit. I achieved a (I think) 64% efficiency with 20L making it into my fermenter.

I just did a gravity check (15 days in) to see if the ferment has hit the expected FG and it came back at 1.021. I planned to let it have another week of conditioning before I bottle any way.

So, up to this point as far as I was thinking I am pretty happy! But now I have done the standard snoop all over the internet and have ran into a lot of posts about ‘Stuck Ferments’ leading to flat beer. I have controlled the temperature of the ferment quite closely, I doubt there has been a swing of 1-2 degrees within a 48 hour period and certainly nothing below 18 degrees.

Until I do another gravity check I wont know if the ferment has officially finished, but if I do and it is still at 1.022 does this mean I have a stuck ferment and when I come to bottle do I run the risk of having flat beer again, as my yeast has died on me? Or with my slightly higher than expected OG can I call my ferment done at a higher FG?

Though I have read tons of posts on these topics I am still a little unsure, what actually is the difference between a stuck ferment and completed ferment? How far away from your target FG means your running the risk of bottle bombs? Or is this negated by simply ensuring the ferment has finished?


Brew Specs:

OG - Target 1.055 - Achieved 1.061 (yea I now know I should have just diluted it a bit)
FG - Target 1.011 - Two week check 1.021

Recipe as follows:

3kg UK - Lager
2kg UK - Wheat
0.4kg UK - Munich

15g Hallertau at 75min
50g Saaz at 0min

US West Coast Yeast

Apologies my browser deleted my title, supposed to be “Newbie Question”
 
So doing a quick attenuation check here https://www.brewersfriend.com/abv-calculator/ that gives you a yeast attenuation of 64% assuming you are refering to Mangrove jacks M44 US west coast ale yeast that has an average attenuation of 78%.

So i would guess this probably is a little stuck, I will be honest I never had a stuck ferment while I bottled so I can't speak to whether it is ok to bottle but have had one finish recently at 1.019 which I kegged with no problems, however I can let the pressure out of the Keg if needed so it's a little different. You will do the beer no harm by leaving it a little longer and seeing if it ferments more, if it doesn't and you are at all uneasy about bottling it I would follow any of the guides about restarting a stuck ferment athumb..

Hopefully someone who bottles more than me will be along in a bit to answer a bit more specifically though
 
Are you using a hydrometer or a refractometer to measure your FG?

What temperature did you mash at?

If you're fermenting at the lower end of the yeast's temperature tolerance, then maybe gently rocking the fermentor and raising the temperature to the middle of the range might get you down to terminal gravity.
 
@hendy

Ah, of course! Attenuation! I did not click onto this despite reading multiple posts on it. Thanks for that!

@harry

Refractometer, I know this is supposed to be less accurate but I have done multiple samples pre boil and post boil and compared the two and it always came within a few points of each other. I just hate the idea of wasting all that beer using the hydro.

I will admit my mash was a little high, I think my kettle held its temp a bit too well. So I started at 76 with an aim for it drop down to 66 ish after grain add. It only dropped to around 71, so I added a little cold water to get it down. I have read people correlating stuck ferments with the mash temp, but I don’t understand how it affects each other, as this is all pre-boil.... so its about to get boiled any way.

I would not say its on the cold end, it is usually hovering around 20-21, if it drops to 19, I get the blanket on it. But I think there would be no harm in trying this, it has another week to settle back down before I rack and bottle.

Cheers.
 
Refractometer

You need to correct your refractometer reading for the presence of alcohol otherwise it'll read high. You can only do that when you've been able to work out your correction factor by comparing your refractometer reading with a hydrometer reading, over a number of brews.

If you have a hydrometer, check your beer with that instead. You might actually be closer to your predicted final gravity than you think.

my mash was a little high

High mash temps can extract unfermentable sugars, so you might not get down to 10.11. Although from what it sounds like, you corrected the temperature quickly.
 
Ah, I calibrated the refractometer (love saying that word) to distilled water when I first got it, but your saying I now need to do some additional tests to ‘dial in’ my refractometer to the hydro. I will get started on that, great tip!

That makes perfect sense, so there would be sugar present but your yeast would not be able to do anything with it. I think I will start my mash lower and bring it up to temp, instead of the other way round. I am not worried about efficiency or yield, just that it tastes good!

Thanks for both answers!
 
Ah, I calibrated the refractometer (love saying that word) to distilled water when I first got it, but your saying I now need to do some additional tests to ‘dial in’ my refractometer to the hydro. I will get started on that, great tip!

That makes perfect sense, so there would be sugar present but your yeast would not be able to do anything with it. I think I will start my mash lower and bring it up to temp, instead of the other way round. I am not worried about efficiency or yield, just that it tastes good!

Thanks for both answers!
I'm the same with using a refractometer over a hydrometer, here's a calculator which will let you convert a post fermentation reading into a true sg.

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

Running your numbers makes me think you got an OG of 13.8 brix and an FG of 5.7 brix? That comes to 1.055 and 1.008 according to my own spreadsheet (BF comes in lower), my refractometer has a correction of 1.017, so it reads 1.7% higher than the hydrometer.
 
That would make a lot of sense! I am bottling this Saturday I will do a hydro check and check my refractometer calibration.

Thanks everyone!
 
Evening, well I just did my first proper rack and bottle and besides my siphon been a bit short, it went extremely well and I have 36 pints conditioning.

I will have to admit defeat on the refractometer, it was miles out! My hydro gave me an exact reading each time of 1.013 the refractometer was all over the place. Suppose I need a proper one if it's going to work.

The bottling wand made the whole exercise so easy! One of the best peices of advice I got from YouTube.

I did find the amount of priming sugar Brewer's Friend told me to add quite high. 200+ g to get me up to 4.5 volumes, but I do like foamy beer, so long as it doesn't explode! My low FG has calmed most of my worries.

Random question, but does the beer ever taste good before conditioning? I fermented for a full three weeks this time but I did not taste any improvement from my first mini batch. Going to give it a good two weeks in the bottle before I touch them.
 
Last edited:
Random question, but does the beer ever taste good before conditioning? I fermented for a full three weeks this time but I did not taste any improvement from my first mini batch. Going to give it a good two weeks in the bottle before I touch them.

Hi @Charles Stanley-Grey and welcome to the forum, I find that tasting a beer before bottling/kegging tastes like it's going to turn out but not so good, it's a rough guide to how it's going to be.
 
Wow, 4.5 volumes is high! I've always found priming to 3 to be more than ample for a 'foamy' beer - you might find that to be a b it excessive, and certainly explains why you're adding 200g priming sugar. My general rule is 130g for a batch - taken from Palmer's 'how to brew'

I generally find the post fermentation sample to be a pretty good indicator of how the finished beer will taste. Any off flavours will likely be apparent by this point, so if it tastes good now it'll likely taste even better when conditioned!
 

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