Why are my FGs so high???

Good day Everyone:

I'm about to brew my fourth batch this weekend and I want to make sure I fix any issues in my processes.

My first 2 batches were extract kits, my most recent was a partial mash. The beer i'm brewing on saturday is a PM as well.

My big question is why can't I get my FGs to reach target. This has happened on all three batches so far. Here is some information.

1st batch. Scotch Ale, pitched hydrated S-04 packet. Fermometer read 68 during high krausen then dropped down to 65F. Primary 7 days, Secondary 17. OG=1.077; Measured FG = 1.027. Instructions stated range of 1.020-1.025. Beer Smith states FG should be 1.020. So finished 7 gravity points above target

3rd batch. Sweet Stout, partial mash. Made a 1.1L Starter. Fermometer read 68 during high krausen, then dropped to 64-65F. Still in Primary (so far 11 days), Leaving for 3 weeks. OG=1.064, SG = 1.025. AHS states OG should be 1.059, beer smith 1.060. Final Gravity should be 1.015-1.017. So finished 10 - 12 gravity points above target

My 2nd batch finished a higher than expected FG as well, however I don't have my readings available to give you the details.

So I'm trying to do everything right by my yeast. I have a stirplate, my basement keeps a very steady temp in the mid 60's and I even have been using a stir bar that attaches to a cordless drill that is used to degass wine for aerating my wort prior to pitching the yeast.

What could be causing my fermentations to crap out prior to getting down to expected FGs? Is there anything i can do to try to get my Sweet Stout down to 1.015 from 1.025 11 days in? What can I do on this next batch to give me a better chance of hitting my final target?

Thanks in advance!

Brad

many things can affect fermentation. the temps you mash at can affect the fermentability of your wart. the temp you ferment at can affect how fast you get to your FG. it sounds like you aerate enough but that to can also affect fermentation. also if you don't pitch enough yeast to begin will not get your target FG.

are you pitching at high krauzen of the starter or letting it ferment down and then adding into the wort? Second- what temperature are you steeping the grains at? If your doing them higher than about 155 then that could impede the ability of the yeast to ferment closer to dryness. The only thing you can do now if they are really done fermenting is to add a different type of yeast. Some people use champaign yeast but it could go lower than your anticipating. If you havent tried yet, rouse the yeast and trub at the bottom and ove to a slightly warmer place to see if you can get it to restart although most of the time i have bad luck with that method...

oh and whats yeasts did you use? just for clarification. some can be problematic

Pretty big beers, your first beer had an OG of 1.077 and it was only in primary a week? Are those beers exploding now? Your 3rd batch may just need more time!

scinerd3000 said:

are you pitching at high krauzen of the starter or letting it ferment down and then adding into the wort?

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I made the starter and left it on the stir plate for 24 hours. I placed in the Frig the night before and decanted off most of the starter wort in the morning, left it out to adjust to room temperature for about 6 hours and pitched it into my cool, aerated wort.

scinerd3000 said:

Second- what temperature are you steeping the grains at?

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This was my first partial mash so I had a little trouble maintaining my temp. I mashed in at 154F and left it my stockpot on the counter covered for 1 hour. After the hour when I checked the temp it had dropped to approx 145F after 60 min. I then moved my grain bag to my sparge water at 168F for 10 minutes.

scinerd3000 said:

The only thing you can do now if they are really done fermenting is to add a different type of yeast. Some people use champaign yeast but it could go lower than your anticipating. If you havent tried yet, rouse the yeast and trub at the bottom and ove to a slightly warmer place to see if you can get it to restart although most of the time i have bad luck with that method...
oh and whats yeasts did you use? just for clarification. some can be problematic

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I'll answer the last question first. My sweet stout used White Labs London Ale 013. I used Mr. Malty to determine starter size.

I do have an extra packet of Safale S-04 dry english ale yeast. Should I pitch that? My basement is the most temp stable place in my house. The rest of the rooms are will be cooler than 65F during the majority of the day and late night and maybe get up near 69-70F during the morning and evening when people are home. My basement stays constantly between 64-66 all day long.

Everything you have posted in your process looks good. The ferm temps are good, aeration is good.

Both those beers are a bit on the big side which always puts more stress on the yeast. Did you add any yeast nutrient to the wort? That can sometimes help get them in top shape to finish a big ferment. Also sometimes for a bigger beer a second aeration once fermentation begins, at say yeast pitch +12-18 hours can be helpful. This step is optional, and obviously you must take care not to introduce nasties into the beer, but the additional oxygen keeps the yeast reproducing a bit longer up front for a larger, healthier colony. I don't know that I would put the drill stirrer back in, but a light shake and swirl can get more oxygen in the wort.

Pharmguy said:

Pretty big beers, your first beer had an OG of 1.077 and it was only in primary a week? Are those beers exploding now? Your 3rd batch may just need more time!

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Yeah I left the Scotch ale in the primary only for a week and then close to three weeks in the secondary. I needed my primary for a second batch at that time. Since then I bucked up and bought more buckets/carboys.

No exploding beers.

Zen_Brew said:

Everything you have posted in your process looks good. The ferm temps are good, aeration is good.

Both those beers are a bit on the big side which always puts more stress on the yeast. Did you add any yeast nutrient to the wort? That can sometimes help get them in top shape to finish a big ferment. Also sometimes for a bigger beer a second aeration once fermentation begins, at say yeast pitch +12-18 hours can be helpful. This step is optional, and obviously you must take care not to introduce nasties into the beer, but the additional oxygen keeps the yeast reproducing a bit longer up front for a larger, healthier colony. I don't know that I would put the drill stirrer back in, but a light shake and swirl can get more oxygen in the wort.

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Thanks for the info. I have yeast nutrients that I used in the starter. I ordered 2 bags instead of one so I have enough yeast nutrient in the house to last like a decade.

Would it be worthwhile to put in a teaspoon of yeast nutrient at this point and shake up the fermenter?

For 5.5 gallon batch I usually put about 2 tsp of nutrient in the boil about 10 mins to flameout. I think once the yeasts are pooped out at the end of a ferment they get little benefit from the addition of nutrient. Sometimes yeast energizer, yeast hulls, or Femaid K (a specific brand of nutrient) can help a sluggish of stuck ferment, but not always and you can end up with some flavor contributions from them if the yeast don't use them. If the gravity is no longer dropping I don't know that I would risk it.

For the beer that you only had in primary for a week, you may have taken it off the primary yeast cake a bit soon. At this point the only thing I would try would be to warm the beer up to about 68-70 and lightly stir the carboy to rouse the yeast.

I think your fermentation temp dropping toward the end is the main problem. The English yeast strains you have been using have a flocculate at the drop of a hat. If your temp starts to drop toward the end the yeast will fall to the bottom and be done. Also, English strains are not know for being highly attenuating. Switch to American ale yeast on your next batch and see what happens.

Ideally you start cool 60-64F
Warm slowly over the first 3 days to 66-72
then keep it warm until you reach the proper ending gravity.

You seem to have the main aspects covered. Healthy Yeast starter, and well Aerated wort.

There are only 3 things I can see from your post that might have not been covered.

It seems you might be transferring from primary to secondary too soon? The term secondary "fermentation" is slightly misleading. You should have a steady FG in your primary for at least 3+ days before you transfer.

Second. You might want to pitch extra yeast for anything starting over 1.060. This either means using two packets of dry, or adding more wort to your starter and letting it sit for few more days to build up the yeast population before pitching.

Lastly, Fermentation temps. Sometimes yeast can rise your batch by up to 10 degrees by releasing heat while eating up all that sugar. The yeast binge on a sugar frenzy and then when they cool back down poop out early. You might want to look into better ferm temp control. You can look up "son of a mother" or find a cheap used fridge, and buy an external thermo to control it.

I too am a beginner. I hope this helps!

amh0001 said:

You seem to have the main aspects covered. Healthy Yeast starter, and well Aerated wort.

There are only 3 things I can see from your post that might have not been covered.

It seems you might be transferring from primary to secondary too soon? The term secondary "fermentation" is slightly misleading. You should have a steady FG in your primary for at least 3+ days before you transfer.

Second. You might want to pitch extra yeast for anything starting over 1.060. This either means using two packets of dry, or adding more wort to your starter and letting it sit for few more days to build up the yeast population before pitching.

Lastly, Fermentation temps. Sometimes yeast can rise your batch by up to 10 degrees by releasing heat while eating up all that sugar. The yeast binge on a sugar frenzy and then when they cool back down poop out early. You might want to look into better ferm temp control. You can look up "son of a mother" or find a cheap used fridge, and buy an external thermo to control it.

I too am a beginner. I hope this helps!

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Thanks for the info, amh001.

I'll answer the questions in order.

In regards to racking to early to a secondary, I agree. On my first batch I transfered a "big" scotch ale to a secondary after only 7 days on the yeast. I had a really really vigorous fermentation and racked it after the krausen had fallen. My next two batches I didn't even use a secondary and left the beer on the yeast for 18 days before bottling. My sweet stout is still in the fermenter and will be for 3 full weeks. I'll start doing daily gravity checks three days before I plan to bottle.

For all to most future batches where I won't be adding fruit or dry hopping (even then maybe) I'll leave it on the yeast for 3 to 4 weeks.

I think this could be the reason why my scotch ale crapped out a little too high.

In regards to yeast pitching, I made a starter for the beer I'm most concerned about...my sweet stout. Should have had a starting gravity of 1.060. My reading stated 1.064. This was a partial mash recipe from an AHS kit. I used Mr. Malty's yeast pitching calculator and made a starter of 1100ml with a starting gravity right about 1.040. I made it on Thursday for a Saturday brewday. On friday night I took the starter off the stirplate and stuck it in the frig. I took it out on Saturday morning, decanted it and left it to acclimate to room temp before pitching into my aerate wort. I figured this beer would have a really fast complete ferm, but it hasn't so far 12 days in. The only other thing I can say about the starter is it smelled awful after sitting on the stirplate for 24 hours. I can't even really describe the smell. Just awful. I attributed the smell at the time to be caused by oxidation from being on the stirplate. It was my first starter so I didn't really have anything to compare it to.

About fermentation temps, the room is at an ambient 62-64F. During high krausen my adhesive thermometer on my primary never got above 69F. Probably no more than 68F even. I thought this was an ideal temp at high krausen (under 70).

I am brewing a Moose Drool clone on Saturday and began my starter today. I'm hoping that I nail down this issue so I don't have the same problem again.

Thanks,

Brad

often with huge beers i never chill the starter. I used to decant the liquid off but then i realised that my starter didint take off quite as well when it was placed in the fridge. Now i pitch (for larger beers above 1.060) at high krauzen (usually ~day 2 or 3) straight into the carboy. As for racking, if you rack to secondary early you can also stall the beer. I would suggest always leaving a large beer like that much longer for 2 reasons. 1) you will give it time to finish and 2) there will be more time for particulates to drop out of solution leaving you with a much clearer beer.

You could try re pitching but you may need a stronger yeast strain to drop those extra points. Alcohol is actually toxic to yeast even though they produce it so getting them to start fermentation on something already containing alcohol is hard. I would give it a try and if it doesn't work, consider grabbing some campaign or wine yeast.

scinerd3000 said:

often with huge beers i never chill the starter. I used to decant the liquid off but then i realised that my starter didint take off quite as well when it was placed in the fridge. Now i pitch (for larger beers above 1.060) at high krauzen (usually ~day 2 or 3) straight into the carboy. As for racking, if you rack to secondary early you can also stall the beer. I would suggest always leaving a large beer like that much longer for 2 reasons. 1) you will give it time to finish and 2) there will be more time for particulates to drop out of solution leaving you with a much clearer beer.

You could try re pitching but you may need a stronger yeast strain to drop those extra points. Alcohol is actually toxic to yeast even though they produce it so getting them to start fermentation on something already containing alcohol is hard. I would give it a try and if it doesn't work, consider grabbing some campaign or wine yeast.

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Thanks scinerd3000!!!

It'll be 2 days from when i began my starter to when I need to pitch it into my next brew. High krausen appears hard to spot when the wort is constantly being stirred.

I do have a extra packet of s-04 dry yeast in my frig. should I try to pitch that?

bce22 said:

I do have a extra packet of s-04 dry yeast in my frig. should I try to pitch that?

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you could try but i think you may still have to go up to a wine yeast to get that to finish out. If my calcs are right your sitting at about 6.5% right now. Most yeasts will have major issues....rehydrate the s04 dry yeast and pitch and then wait a few days and see where your at. If nothin has happened by then i would throw some campaign yeast...either montrochet or pretty much any neutral wine yeast. Some of the lavlin strands are great too but my LHBS doesnt have them

I'm going to take your advice to the tee. Thanks for all the information!!!

I Love This Site!!!

Read this Blog Article, especially the last couple of paragraphs. Lowering temperatures as the yeast are slowing their activity, especially in high-gravity beers, is a big no-no.

Heyas,

I see your doing another batch. I read that racking to a yeast cake from another healthy beer can sometimes finish fermenting your stuck beer. I'm actually about to try this. I have a Dry Stout that just had a blow out, and a Sweet Stout that is stuck at 1.23. Assuming the Dry does well, I'm going to rack the stuck sweet on top of it.

Best of luck
~AMH

bce22 said:

Measured FG = 1.027. Instructions stated range of 1.020-1.025. Beer Smith states FG should be 1.020. So finished 7 gravity points above target

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Ummm.. if the instructions say 1.025 and you had 1.027 isn't that .002 difference? Why are you using Beer Smith as THE answer here?