FG too high!

The Homebrew Forum

Help Support The Homebrew Forum:

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

kevin1911

Active Member
Joined
Oct 26, 2015
Messages
26
Reaction score
2
Location
falkirk
Evening all!

I'm a relative newbie to the BIAB (or any brewing for that matter), currently on my second batch. The first was an American Pale Ale that was finally ready for tasting earlier this week. It won't win any awards but it's definitely drinkable, and even had fizz, so I was quite happy for a first attempt.

My second batch (a Belfast Blonde) is reaching the end of its 2 weeks in the FV tomorrow. Fermentation seemed to have stopped by last weekend (I.e. After around 9 days). I took a gravity reading yesterday and again today and they are both 1.024. The FG is supposed to be 1.012 - 1.016. There are no bubbles coming out of the airlock, and haven't been for at least 4 days now. The OG was 1.055, which is about spot on according to the recipe.

There seems to be quite a lot of sediment in the small samples I've taken for the gravity readings too - yesterday I put this down to the fact that I had to turn the FV round to get the tap in the right place, but it doesn't seem much better today.

Any suggestions on what the best course of action would be? Leave for another week? Add more yeast? I should maybe add that the initial fermentation started quite quickly (~3hrs) and was VERY active for the first 6 days or so, much more active than the first batch. I also noticed that the temperature was slightly higher than expected at 23.5C....it cooled towards 18C after around 2-3 days.

Thanks guys (and gals)
 
I think I've got the same geterbrewed set up as you. I have found some beers the gravity finished high. It may be related temp of mash. I find after the initial fermentation it's got to increase by a couple of degrees a day for 3-4 days as this helps yeast chew some gravity points. I use a builders bucket and fish tank heater.
 
Usual advice I suppose; give it a gentle stir with a sanitised spoon or swirl the contents of your FV to resuspend the yeast but don't get any air in, and/or move into a warmer place say 22*C.
And you could try adding 100-200g of sugar dissolved in a little water stirred in, to give the yeast more to chew on.
But try to keep the minimise the time the lid is off.
 
At the risk of letting air in, I'm sure we've all learned thy if you lift the fv by the handle the weight of liquid draws a negative pressure and can pull the air lock water into your beer.

NOOOOOO!

So I always crack the seal of the fv before I swirl or move it. Just be quick ;-)
 
Thanks all. I've given it a good swish around, so will wait until the morning to see if there's any movement in the air lock, and if not will try a warmer place then sugar in that order. Does the yeast just lay dormant at the bottom of the fv, out dies it actually die off?
 
Initially it will settle. If you leave it a few months the yeast will begin to die and lyse. Apparent if this starts to happen you get a soapy taste in you beer due to the release cell membrane into the beer. Never had it myself.
 
Apart from the above advice which I think is sound , something else to possibly consider, maybe you're mashing slightly too high? have you tested your thermometer? with another just to check because if you're mashing at say 68 to 69 you may end up with more unfermentable sugars.

Not saying that is it but just something else to consider.
 
I was going to say just what Covrich said.
If you do have too many unfermentable sugars in your brew you could try using some amylase enzyme which breaks down longer chain starches into fermentable sugars. I've had a couple of stuck brews in the past - amylase worked on one of them but only had a little effect on the other. Worth a try though. I got mine off ebay which avoided the normal delivery charges homebrew suppliers seem to apply to everything.
I now make sure my mash temperatures are on the low side especially at the beginning of the mash when most enzyme activity takes place and haven't had a stuck fermentation since.
 
I have a similar problem that my FG is at the higher end of expectation. I mashed at 69'c in an attempt to get a "fruitier" taste, I'll try next batch back at 66' to see if that makes a difference.
 
I have a similar problem that my FG is at the higher end of expectation. I mashed at 69'c in an attempt to get a "fruitier" taste, I'll try next batch back at 66' to see if that makes a difference.


for sweeter and fruitier tastes you can probably achieve that using a yeast strain
 
I have a similar problem that my FG is at the higher end of expectation. I mashed at 69'c in an attempt to get a "fruitier" taste, I'll try next batch back at 66' to see if that makes a difference.

It makes a ton of difference. Low, 62 to 65 produces fermentable sugars. Beer done at these temps are called dry.
I like to do step mashing. I start low for 20 minutes then step it up 2 degrees every 10 minutes till my final mash out temp, 70. Then sparge from there.
I'm trying to get my hands on a chugger pump so when I hit my 60 min mark, I can start sparging right away from water in my other kettle. Hand pouring 11 to 15 liters of water takes time and loose a lot of heat.
 
Now you mention it, I did have some trouble keeping the mash at the right temperature. It dipped quite a bit twice during the mash, so I turned on the element to bring it back up to temperature. It ended up getting up to 73c I think due to a combination of the thermometer having quite a lag when updating the current temp, and the element still giving out it's residual heat after being turned off. Typically, the mash tun seemed to hold onto this higher temperature for quite a while. The recommended mash temp is 67c. This is most likely the problem here isn't it?

Should I add the dissolved sugar while I wait for the amylase enzyme to arrive, or just wait?

Cheers all
 
Regular table sugar is mostly not fermentable. You need corn sugar or some kind of dextrose. But this won't help the type of sugar you produced during mash time.
My suggestion is just enjoy your sweeter beer and learn.
Thermometers and a few other things are items you want to have good quality.
 
Well I added some dissolved sugar and moved it to somewhere a little warmer. It's been bubbling away a bit more, but has only dropped to 1.021.

The enzymes arrived in the post today, but not sure if I'll add it or not, as it seems that once it's added it will just go on breaking down the non fermentable sugars until it's a very very dry beer. Think I'll maybe just let it settle in the fv (still quite a lot of sediment), and will bottle it and see how it tastes once it's conditioned. Lesson learned!

Need to find a reliable thermometer!
 
The problem you have is that .010 of non fermentable sugar still in there. Adding regular sugar will boost the gravity but regular table sugar has a loss of about 5% of non fermentability. So you might be back to the same reading once the yeast do their job.
On your next brew, take note on a few things. Mash temp and agitation of the wort.
All of my stuck batches were due to lack of oxygen when pitching. You really need to shake it up really well. To put it in perspective, big Brewers oxygenate with 100% oxygen for up to an hour. So shaking your batch for 10 seconds doesn't really cut it.
 
The problem you have is that .010 of non fermentable sugar still in there. Adding regular sugar will boost the gravity but regular table sugar has a loss of about 5% of non fermentability. So you might be back to the same reading once the yeast do their job.
On your next brew, take note on a few things. Mash temp and agitation of the wort.
All of my stuck batches were due to lack of oxygen when pitching. You really need to shake it up really well. To put it in perspective, big Brewers oxygenate with 100% oxygen for up to an hour. So shaking your batch for 10 seconds doesn't really cut it.

Pour into FV from a great hight :-) that or I have used an oxygen stone for fish tanks in the starter wort to get the little guys going.

Not sure if would work in the FV as you might be pumping in 'dirty' air.
 
It might be a mix of low oxygen and a lot of non fermentables in there. I wouldn't pump air in.... You could stir it but the problem is just above the beer is a cushion on co2 so even if you lightly stir it, your not introducing oxygen.
What temp are you keeping it? You could raise it up to 23 or 24 degrees just to get that last bit of sugar.
 
Back
Top