First All Grain - Stuck Fermentation

[AnchorBock]

I did my first all grain batch 11 days ago, ended up at 1.050 (was aiming for about 1.055, but ended up with about 6.5 gallons in the carboy when I was aiming for 5.5 gallons - started with too much water I guess). Made an oatmeal stout. I pitched a 2 liter starter with WL002 at 70F. Beer has maintained a temp of 66-68F for 11 days now. I am now at 1.025 and have been for 3 days now. I roused the yeast yesterday by stirring the cake at the bottom - no change so far.

I fear I did not oxygenate enough and that is why this happened (I merely had the racking tube just below the carboy mouth and it did not foam much), what are other likely causes?

I'm debating how to go about trying to get the beer to finish closer to 1.015, I am brewing this weekend so I could rack onto that cake as I have seen others suggest, but not for about 2 more weeks. I could also pitch more yeast, if so should I just make a bigger starter for this weekend (using WL005 British Ale) and add some of that - or should I use dry champagne yeast as some suggest?

I've also seen many suggest raising the temp, but I don't have a good way to do that yet - haven't built a fermentation chamber for heat yet. I suppose I could stick it in a closet with a space heater?

Any other ideas?

 

[Tall_Yotie]

It probably is an oxy issue. Did you add any yeast nutrient to the boil? Also, did the starter seem to have a nice amount of yeast growing in it?

I would not add more yeast, as from what I have heard you can kill or get weird flavors from fresh yeast being tossed in an environment with alcohol already in it.

After you sloshed your carboy around, give it a little time. Also, WLP002 in my experience can take 2 weeks to finish doing its thing. Don't call it stuck until you get the same reading a couple days later. I would check it tomorrow or best Friday and see if it has shifted.

The best thing to do is wait and see, as if it fixes itself then it is the best response.

 

[AnchorBock]

It probably is an oxy issue. Did you add any yeast nutrient to the boil? Also, did the starter seem to have a nice amount of yeast growing in it?

I would not add more yeast, as from what I have heard you can kill or get weird flavors from fresh yeast being tossed in an environment with alcohol already in it.

After you sloshed your carboy around, give it a little time. Also, WLP002 in my experience can take 2 weeks to finish doing its thing. Don't call it stuck until you get the same reading a couple days later. I would check it tomorrow or best Friday and see if it has shifted.

The best thing to do is wait and see, as if it fixes itself then it is the best response.

I added 1/4 tsp yeast energizer to the starter boil, but no nutrient, I figured DME has enough nutrients. There was a lot of yeast growth. I guess I should wait longer since rousing the yeast, but it's been at 1.025 for at least 3 days (that was my first reading since I pitched).

 

[SwampassJ]

What was your recipe, mash temps and mash times?

 

[Powers]

with a stout, if my fermentation stops between 20 and 25, i'm usually tempted to let it go and just accept that it will be a sweet stout. most stouts are higher in final gravity anyway, and i usually don't like to pitch more yeast due to the alcoholic environment and the fear it may attentuate too much, resulting in too low of a final gravity. nobody likes a thin stout!

 

[KAMMEE]

My $0.02, try the closet / space heater idea... just make sure it doesn't get too hot. Up around 72 degrees should get it going again. If that doesn't work, make a new starter with yeast nutrient, pitch that and try the higher temps.

 

[AnchorBock]

Thanks for the responses. I basically used jamils recipe from BCS and mashed at his suggested temp. Im at work so i cant check. 90 min mash with no mashout.

 

[coypoo]

Is it a milk stout? I would also agree with the temp increase and trying to rouse the yeast a little bit. If nothing happens after a week or so, bottle and enjoy.

 

[AnchorBock]

I roused the yeast again and have it im a closet with a space heater set to 72f. Ill post and update tomorrow or sat if anything happens. Thanks again.

 

[AnchorBock]

Recipe:
10 lbs Maris Otter
1 lbs Flaked Oats
.7 lbs Pale Chocolate
.8 lbs Victory
.5 lbs Crystal 80
.5 lbs Black Roasted Barley
2 oz. Kent Goldings 60 minutes
WLP002 - 2 liter starter
8.5 gallons tap water, crushed campden tablet prior to mash to get rid of the chloramine.
I mashed at 152f, Jamil's recipe called for 154f I just realized.
6.5 gallons into fermenter
1.040 preboil
1.050 postboil
1.025 yesterday (after 11 days in primary)

I am wondering if I screwed the mash up somehow? Or is that not likely since it already fermented through .025 sg? I just don't want the same thing to happen this weekend when I brew, need to know what I should change (if anything). My thermometer is accurate, I did the ice-water test right before doughing in. I used the finest crush at the LHBS, but did not double crush as many do with BIAB since it seemed to be pretty fine already.

Don't mean to post so much in my own thread, but I don't want this next batch to go south. Thanks for any input.

 

[TANSTAAFB]

152* instead of 154* should have produced MORE fermentables and dryer finish, not less. You could try adding some amylase from your LHBS...others have had success with that getting a stuck fermentation going but it will dry it out a lot. I prefer a dry stout to a sweet stout, but that's just me.

Good luck and don't worry about your next brew. It sounds like you did everything right but the yeastie beasties sometimes work in mysterious ways.

If it were me I'd just leave it alone for another 3-4 weeks, bottle, enjoy, and try to fix it next time.

 

[Powers]

lets do some quick and dirty efficiency math.

2 row (10 x 37) + oats (1 x 28) choco (.7 x 34) + victory (.8 x 35) + cyrstal (.5 x 34) + barley (.5 x 25) = ~480 / 5 gallon batch = 1.096 optimal original gravity

Now that's 100% effeciency, which you won't have. So let's say you had 65% efficiency in your mash and sparge. 96 x .65 = 1.0624 original gravity at 65% efficiency.

You are getting less than optimal efficiency from your mashing process, about 52% (50 your actual OG / 96 optimal OG). Now those numbers are very rough (I guess on the oat yield), but your mashing process was definitely lacking in some aspect. my guess would be that some or many of your grains were not crushed, or not crushed adequately. my two cents.

 

[AnchorBock]

Keep in mind i mashed 8.5 gallons of water and ended up with 6.5 gallons of wort in the fermenter, thatd likely raise the efficiency a few points. Im going to crush the hell out of the grain for tomorrow and do a mashout. Using a very similar recipe minus the roasted malt for a brown ale so i will change a few things in my process, finer crush, a gallon less water, mashout step.

 

[CPooley4]

Are you using any kind of brew program to help with volumes for strike and sparge water amounts?

 

[flabyboy]

What was your mash pH?

 

[AnchorBock]

Ya i used the biab calc from the biabrewer.info site and i have strike water calc on my phone. My mash temp stayed quite consistent. Unsure of mash ph but i did buy strips for this weekend. The color of the strip didnt change when i tested my tap water..but im at work so i dont have the number in front or me.

 

[CPooley4]

How did you end up with so much volume if you're using a bre calculator? Are you sure it's accurate?

You may want to download my brew chart linked in my signature below if you want a good free program to use.

 

[AnchorBock]

I thought the volume was high too, but it accounted for a lot more trub and boil-off then I ended up with. I have made adjustments to the calculator for my next batch. I'll check out your calculator. Thanks.

 

[2bluewagons]

FWIW, I vote for either leaving it as is (assuming the raised temp does not help), or racking over to the cake when it's free. I have used that tactic at least once to take a few points off.

I calc your efficiency at 68%, so no real problems but not great either. If for some reason your crush was different on your base malt than your specialty grains, you could get disproportionate extraction I suppose, leading to a less fermentable wort.

 

[kanzimonson]

I made a 1.065 oatmeal stout with English Ale and it finished at 1.024. Mashed at 154. It was 28.5% specialty grains, which includes 10% oats and some aromatic.

That sucker is done. You could probably squeak out a couple more points, but I'm a big fan of not turning our beers into experiments.

 

[AnchorBock]

Well my second AG batch has been in Primary for 8 days, and at 1.033 for 3 days now - so I have another stuck fermentation (was planning on getting around 1.015). This batch started at 1.062, made a 2 liter starter of WLP005. Even though I'm only 2 batches in, I'd say there is something wrong with my process, most likely my mash process.

90 minute mash at 152*, stirred at 30 minutes and was at 151*. Stirred at 60 minutes and was at 148*, at 90 minutes I was at 146*. I did a mashout at 168*. I've been brewing in my garage and it was about 20* when I brewed this. Once again this was BIAB. I used the finest crush on the mill at the LHBS, maybe I'm not crushing the grains enough for BIAB?

10 lb Pale Malt, Maris Otter
1.00 lb Oats, Flaked
0.5 lb Caramel/Crystal Malt - 40L
0.5 lb Caramel/Crystal Malt - 80L
1.0 lb Pale Chocolate Malt
0.5 lb Aromatic Malt

7.75 gallons water
5.5 into fermenter
Fermented at 68*, got up to 72* when fermentation was real active and it is now at 66*.

I'm getting close to my target gravity, is it possible to hit your gravity, but not have enough of the right enzymes/sugars for the yeast to attenuate fully? Anyone have any ideas of what I'm doing wrong?

I think I'll pick up some AE for this one tomorrow and see if I can get it to finish out

 

[TANSTAAFB]

Well my second AG batch has been in Primary for 8 days, and at 1.033 for 3 days now - so I have another stuck fermentation (was planning on getting around 1.015). This batch started at 1.062, made a 2 liter starter of WLP005. Even though I'm only 2 batches in, I'd say there is something wrong with my process, most likely my mash process.

90 minute mash at 152*, stirred at 30 minutes and was at 151*. Stirred at 60 minutes and was at 148*, at 90 minutes I was at 146*. I did a mashout at 168*. I've been brewing in my garage and it was about 20* when I brewed this. Once again this was BIAB. I used the finest crush on the mill at the LHBS, maybe I'm not crushing the grains enough for BIAB?

10 lb Pale Malt, Maris Otter
1.00 lb Oats, Flaked
0.5 lb Caramel/Crystal Malt - 40L
0.5 lb Caramel/Crystal Malt - 80L
1.0 lb Pale Chocolate Malt
0.5 lb Aromatic Malt

7.75 gallons water
5.5 into fermenter
Fermented at 68*, got up to 72* when fermentation was real active and it is now at 66*.

I'm getting close to my target gravity, is it possible to hit your gravity, but not have enough of the right enzymes/sugars for the yeast to attenuate fully? Anyone have any ideas of what I'm doing wrong?

I think I'll pick up some AE for this one tomorrow and see if I can get it to finish out

Your process sounds dead on man. I can't think of one recommendation based on the info you have provided. 20-30 minutes is really all that is needed to convert most modern malts so 60 min is the norm to be sure and after 90 min you should have no problems.
Have you calibrated your thermometer? How did you make your starter?

 

[AnchorBock]

Your process sounds dead on man. I can't think of one recommendation based on the info you have provided. 20-30 minutes is really all that is needed to convert most modern malts so 60 min is the norm to be sure and after 90 min you should have no problems.
Have you calibrated your thermometer? How did you make your starter?

I did the icewater calibration the night before. I used 200 grams DME, 2 liters water, 1/4 tsp yeast nutrient. Pitched at 70*, had a lot of krausen at about the 18 hour mark. At 24 hours it had dropped, placed it in the fridge for about 12 hours before pitching at 68*. Now that I think back on it, I didn't have the yeast get back up to fermentation temps from the fridge prior to pitching, could that have done it? On the first batch (oatmeal stout), I didn't decant so it was at the right temp when I pitched.

 

[kanzimonson]

Process sounds fine, ruling out any equipment problems.

It's not great that your temps are falling right at that critical moment of fermentation but I'd be surprised if this is the only problem. Still, you might want to buy a $16 heating pad at the drug store (the kind for injuries) to wrap around the fermenter and maintain temp.

 

[TANSTAAFB]

Now that I think back on it, I didn't have the yeast get back up to fermentation temps from the fridge prior to pitching, could that have done it?

The starter was at fridge temps (35-40*F)? You can shock the yeast doing that.

Check out this thread

https://www.homebrewtalk.com/f39/refrigerating-yeast-preparing-pitch-75145/

Lot of experienced brewers chimed in right away. Seems the consensus is its not a good idea, but a lot have had no problem doing what you did.

 

[AnchorBock]

One last thing I thought of, I shook the carboy for about 5 minutes to oxygenate - maybe that wasn't enough (had a good layer of foam)?

 

[TANSTAAFB]

One last thing I thought of, I shook the carboy for about 5 minutes to oxygenate - maybe that wasn't enough (had a good layer of foam)?

That should be fine for a 1060 brew

 

[jkreuze]

Note that neither of those yeasts is a real burner when it comes to attenuation; WL002 attenuates to 68%-70%, WL005 attenuates to 67%-74% (per Midwest's descriptions on their website).

 

[TANSTAAFB]

If you want to test your process you might try brewing a drier style with an attenuative yeast. I brew my basic dry stout recipe with Wyeast 1056 because I like the clean, dry finish it produces, allowing the roasty character of the grains to come out.

Mash low as well, like 149-151*F. You may be getting more dextrins than you want. Last one got down to 1014 (I mashed a litle higher). I also have a very simple Cream Ale that gets down to the 1008 range w/ 1056.

 

[AnchorBock]

I think the most likely culprit is the lack of temp control. Ill be building a fermentation chamber before brewing again so i can test the theory.

 

[AnchorBock]

The more i think about this the more i wonder if the problem is being caused by using my tap water. I had not used it prior to these two batches but had bought jugs from the store. I added a crushed camden tablet to drive off chloramine or chlorine prior to mashing..guess ill have to do more research on my tap water. Anyone have any thoughts as to whether water would cause stuck fermentation? Its not well water and my city also gets water from minneapolis.

 

[kanzimonson]

Maybe your water has more water per gram than my water.

 

[AnchorBock]

Maybe your water has more water per gram than my water.

Thanks for that.