Question about a high gravity reading after 5 weeks

Homebrew Talk

Help Support Homebrew Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

_Keven

Active Member
Joined
Nov 17, 2023
Messages
33
Reaction score
13
Hello, I recently have been brewing a triple: https://www.northernbrewer.com/products/belgian-tripel-extract-kit. Brewing day was around 5 weeks ago. I used the wyeast 3787 with an OG of 1.072. Today I moved it to a secondary and took a FG reading of just 1.020 which is a bit high. Now after its sitting in the secondary I noticed that it still bubbles every 5-10 minutes so its definitely not done fermenting. My question is if I want a FG of 1.010-1.015 will this slow fermentation get me there? Or should I somehow wake up more yeast (I'm not sure how to do that but read that it is a possibility). Any help would be appreciated.
 
With a current SG of 20 after 5 weeks, the yeast may have fermented all they are going to ferment.

1708278816697.png

https://wyeastlab.com/product/belgian-high-gravity/

72 * (1 - .75) = 18

1708278916757.png

https://www.northernbrewer.com/products/belgian-tripel-extract-kit
 
Ah I see, is there anything I can do to lower the FG? Could I add in more/different kind of yeast to bump up the abv or would that just ruin the beer?
Extract brews are notorious for stopping fermentation at ~1.020. Sounds like that is what might have happened.

You probably don't need more yeast, but a more fermentable wort. You can try adding some amylase enzyme to the fermenter (yes it does work at fermentation temps, just much slower than at mash temps.) But, do not use glucoamylase (aka amyloglucosidase or just gluco, unless you want the beer to finish somewhere around FG 1.000.

If the starting wort contained any longer chain dextrins (non-limit dextrins), the added amylase can convert the long chains into short chain dextrins (limit dextrins) and fermentable sugar.

Brew on :mug:
 
My question is if I want a FG of 1.010-1.015 will this slow fermentation get me there?
I think 1.015 is just about the lowest you can expect with that wort and that yeast. One thing I've never liked about NB kits is that they don't tell you how fermentable their extracts are or what to expect for a FG.
 
Extract brews are notorious for stopping fermentation at ~1.020.
Back in 2018, I brewed the BCS Tripel recipe a couple of times with either T-58 or MJ 31.

One finished around 20 (as estimated), one finished around 10 (as estimated).

Replacing some of the DME with sugar resulted in an even lower FG.



Assuming a correct hydrometer reading, extract recipes "stuck" at OG 20 are most likely:
  • Bad recipe conversion (e.g. when the all-grain wort was fermented low)
  • Bad yeast selection (picking a strain, like Windsor, that can't ferment maltotriose)
  • poor fermentation practices (e.g. fermenting at room temperature where there is a large variation between day and night temperature).
 
My question is if I want a FG of 1.010-1.015 will this slow fermentation get me there? Or should I somehow wake up more yeast (I'm not sure how to do that but read that it is a possibility). Any help would be appreciated.
To me, it looks like this recipe is working as intended - but not meeting your expectations.

I would go with what's there. Most attempts attempts to fix a beer at this point have a reasonably high risk of making the beer worse.

If you want to try something anyway, consider getting some MJ M29, MJ M31 (or similar strain), re-hydrate per their instructions, add yeast nutrient, and see what happens. Note that pitching into 7% beer is a very hostile environment and "forum wisdom" states that this will do nothing other than kill the yeast. (But ... having recently "built up" a failed 5.5% brown ale (accidentally mashed high, then used Windsor :( ) from 5.5% to 11% using multiple yeast pitches, sugar, and brewers crystals), I suspect the true story is a lot more complicated).

Worst case? nothing changes. Better case? with a big enough pitch, perhaps enough of the yeast survives to lower FG.​
eta: bottle conditioning yeast (e.g. CBC-1) or wine yeast won't work as those strains of yeast won't ferment complex sugars found in beer wort.

eta: pitch rate? maybe two sachets (or one sachet each of MJ 29 & MJ 31).
 
Last edited:
Hello, I recently have been brewing a triple: https://www.northernbrewer.com/products/belgian-tripel-extract-kit. Brewing day was around 5 weeks ago. I used the wyeast 3787 with an OG of 1.072. Today I moved it to a secondary and took a FG reading of just 1.020 which is a bit high. Now after its sitting in the secondary I noticed that it still bubbles every 5-10 minutes so its definitely not done fermenting. My question is if I want a FG of 1.010-1.015 will this slow fermentation get me there? Or should I somehow wake up more yeast (I'm not sure how to do that but read that it is a possibility). Any help would be appreciated.

Did you use one pack of Wyeast 3787? Did you note the packaging date on that pack? Did you make a yeast starter?

Edit: I can see that NB does pretty firmly suggest using two packs of yeast because that's how many are forced if you add the yeast via the dropdown on the recipe page. Unfortunately, even if you got two packs, it is almost certainly not enough yeast. You can see that they also encourage the use of a starter. Using typical calculators, if the packs were SUPER fresh, like packed a week before brew day, you would need 4 packs. The more common situation is that the packs are more like 1-2 months old.. At 2 months old, you'd need 7 packs.

If you took those two packs and pitched them into a 2 liter starter, you'd achieve the right cell count.

This is really a case of a taking on a very challenging style of beer with a yeast format that is expensive or skillset dependent. Either explore yeast starters or stick to dry yeast for a while.
 
Last edited:
Sugar will raise ABV. It will not lower FG.
Most yeasts will attenuate table sugar (sucrose) 100%, producing only ethanol and CO2. Since ethanol is lower density than water, and beer, increasing the % ABV, without adding any high SG components will lower the SG.

Let's look at an example:

Assume 5 gal of beer at 1.020 SG. 2 lb of sucrose will create 1.08 lb of ethanol (SG of 0.789), which has a volume of 1.08 lb / (8.33 lb/gal * 0.789) = 0.164 gal. The beer has a weight of 5 * 8.33 lb/gal * 1.020 = 42.483 lb. So, after adding sugar (and waiting for fermentation to finish), we have a total weight of 42.483 + 1.08 = 43.563 lb, and a volume of 5 + 0.164 = 5.164 gal. The SG will be 43.563 lb / (5.164 gal * 8.33 lb/gal) = 1.013.

The above ignores the non-ideality of ethanol/water solutions, but the error should be small.

Brew on :mug:
 
The recipe was about 10 % sugar anyway, but no mention of fermentation temperature for primary or secondary.
An FG of 1.020 assuming measured with hydrometer? doesn't mean the beer is going to be a bad one.
You could lob in a Saison yeast and they can munch a lot of different sugars. Grain profile could fit a saison.
I'd be more inclined to bottle it with a bit of fresh yeast and a little dextrose and wait.
 
Sugar will raise ABV. It will not lower FG.
Fermentable sugars have been added by brewers to boost attenuation since at least the 19th century. Think British and Belgian inverts, then all the simple sugar syrups added by commercial brewers today. Perfectly acceptable too.
 
Brewers Friend recipe calculator:
  • 1# DME for 1 gal wort
  • 1# DME & .25# sugar for 1 gal wort
View attachment 842212

View attachment 842213
So about 73% vs 79% apparent attenuation?

Edit: when a brewer expresses disappointment about FG finishing higher than expected, the primary reason is the beer has a lower ABV than planned. That’s what fermentation is about fundamentally. Producing a beer at x% ABV.
 
Last edited:
Yes, sugar will raise OG, ABV, and apparent attenuation.

But ... IIRC ...

OP was looking for ways to lower the FG in the existing wort/beer.
In practice, it's not that simple. People phrase their questions in a way that is limited by their understanding. OP may just be following a recipe and the numbers are not matching causing anxiety.

The beer actually might be fine where it is. If it's coming across as too sweet (not by instruments but by sensory), adding highly fermentable sugar may have helped in the primary to add more apparent attenuation and the balancing effect of higher ABV, but I don't believe the yeast colony to be capable of dealing with additional sugar at this time.

My advice would be to raise the temp of the secondary to about 75F for a few more days and just live with what you have. If it's still a little sweet, I would add some vodka to achieve a more appropriate ABV/sweetness balance.
 
Yes, sugar will raise OG, ABV, and apparent attenuation.

But ... IIRC ...

OP was looking for ways to lower the FG in the existing wort/beer.
And what’s the primary reason for a brewer to want a lower FG?
In practice, it's not that simple. People phrase their questions in a way that is limited by their understanding. OP may just be following a recipe and the numbers are not matching causing anxiety.

The beer actually might be fine where it is. If it's coming across as too sweet (not by instruments but by sensory), adding highly fermentable sugar may have helped in the primary to add more apparent attenuation and the balancing effect of higher ABV, but I don't believe the yeast colony to be capable of dealing with additional sugar at this time.

My advice would be to raise the temp of the secondary to about 75F for a few more days and just live with what you have. If it's still a little sweet, I would add some vodka to achieve a more appropriate ABV/sweetness balance.
My understanding was that these kits come with wort that isn’t as fermentable as claimed on the box.
 
My understanding was that these kits come with wort that isn’t as fermentable as claimed on the box.
Or the yeast wasn't up to the challenge given its age and handling and/or the temperature of the ambient environment. We're only talking about a few gravity points or attenuation percentage and any of these variables can easily explain the current situation. More yeast, healthier yeast, nutrient, oxygenation, temp ramps, etc are all in the high gravity fermenter's toolkit.
 
You could add a couple packets of Fermentis BE-256. It's more attenuatative and faster than 3787. A friend did that on a Belgian Dark Strong Ale that stalled and it got the FG down significantly as I recall.
I think I might try this despite what others have said (the abv is quite hostile for the yeast) because at this point what's the worst that can happen? I'm hoping I can get it down to 1.015, I just don't want the beer to be too sweet.
 
Or the yeast wasn't up to the challenge given its age and handling and/or the temperature of the ambient environment. We're only talking about a few gravity points or attenuation percentage and any of these variables can easily explain the current situation. More yeast, healthier yeast, nutrient, oxygenation, temp ramps, etc are all in the high gravity fermenter's toolkit.
Would it be too late to add yeast nutrients/energizer at this point?
 
I think I might try this despite what others have said (the abv is quite hostile for the yeast) because at this point what's the worst that can happen?
You're right that nothing bad is likely to happen, but people are advising against it because nothing good is all that likely to happen either.
I just don't want the beer to be too sweet.
Have you tasted it? Have you checked the gravity again since your original post?
 


I think I might try this despite what others have said (the abv is quite hostile for the yeast) because at this point what's the worst that can happen? I'm hoping I can get it down to 1.015, I just don't want the beer to be too sweet.
BE-256 (at 9-11% tolerance) seems like a good choice. Yeast nutrient will help. re-hydration may help. In "hostile" environments (low pH, high OG) Fermentis suggests re-hydration - so it may help here as well.

There are examples of pitching yeast into fermented beer (e.g. Microbrewed Adventures. Sam Adams Triple Bock recipe (p 307)).

Like I said in #11, "forum wisdom" suggests this won't work. OTOH, there are three or four replies that either suggest it might or suggest giving it a try anyway.
 



BE-256 (at 9-11% tolerance) seems like a good choice. Yeast nutrient will help. re-hydration may help. In "hostile" environments (low pH, high OG) Fermentis suggests re-hydration - so it may help here as well.

There are examples of pitching yeast into fermented beer (e.g. Microbrewed Adventures. Sam Adams Triple Bock recipe (p 307)).

Like I said in #11, "forum wisdom" suggests this won't work. OTOH, there are three or four replies that either suggest it might or suggest giving it a try anyway.
Yep I'm going to order the yeast today and get a yeast starter going asap, I'll keep you posted if I see any notable results.
 
This.

We drink beer, not numbers. So I'll ask again - Have you tasted it?
You know it does taste pretty good, I'm just letting it sit in a slightly warmer environment hoping that will help. I haven't pitched any more yeast yet.
 
If it tastes good and is sufficiently dry, it may be fine, but it seems like it could be under-attenuated at 1.020 based on the recipe. If you bottle, and the yeast continues to ferment the beer slowly, you may get gushers or exploding bottles. I'd suggest using heavy bottles and keeping them contained in something for a while.
 
Back
Top