Nottingham yeast and slow fermentation?

First, I have to apologize for this long post....want to get as much info in here as possible!!

The last two batches I have made with Nottingham for simplicity as it was the first times using the new brew system, I didn't want to complicate things further with liquid yeast.

The first batch was a variant of Ed's Haus Pale ale. 22-23 gallon batch - pitched 4 packets of yeast. Now, that one had a stuck fermentation (my fault - temp got too low after the first 4 days). Was looking for 1.013. Stopped at 1.020. I made a starter out of another packet of Notty and pitched (after warming up the fermenter and keeping the temps in 67-68 deg. range.) That helped somewhat - lowering the gravity to about 1.018 in a week or so. I just chalked that one up to a learning experience and kegged the beer at that FG on Saturday. (still tasted pretty good - of course more body than I was looking for) I noticed that there really wasn't much in the way of yeast cake on the bottom of the fermenter. I was expecting a large yeast cake with such a large batch....?

Now this is the one that puzzles me:

The second batch was an american stout - OG was at 1.056. Looking for 1.012 for a FG. This one was again a 23 gal batch. Used two glass carboys (one 5 gal and one 6 gal) and a large 14 gal. plastic fermenter. Again, used Notty. Pitched one packet in each of the carboys and two packets into the large plastic fermenter. I checked the gravity at about 10 days after pitching and it was at 1.025. ? (checked 2 fermenters - same results) Temps were very constant this time (67 to 70). So, I figured I would give the fermenters a shake to rouse the yeast. As soon as I swirled the fermenters, the airlocks/blowoffs started bip-bipping again. Checked the gravity 2 weeks after pitching (Saturday), and the gravity was STILL at 1.025!!?? So....again, I roused the yeast and again, they started bubbling!

Like I said, this is the first times I have used dry yeast. I never had a slow fermentation with liquid yeast. All I can figure is I underpitched???

Am I missing something? Any body else have a slow fermentation with Notty?

My game plan is to rouse the yeast daily, as long as I see airlock activity after shaking. If that doesn't work.... I guess I make another starter and re-pitch. I have seen that a lot of you guys really like Notty.

BTW, per my standard procedure, I oxygenated with medical grade oxygen / airstone and used a little yeast nutrient in the boil. My thermometer temp probe is taped to the carboy with bubble insulation over it.

Thanks for your insight into this frustrating situation

I've used Nottingham quite often to great success. Good attenuation and fairly quick start-up. Temperature would be my first guess toward the culprit, but it sounds like you have that under wraps. My next suggestion would be to check the date on the packets. If it's old yeast, it might not be as viable. It's unliely you underpitched since Nottingham has more than enough of a cell count for a 5-6 gallon batch at a 1.056 OG.
My only other thought is to check you hydrometer. Make sure it's calibrated properly. Good luck.

Thanks for the input, Jackson.

The Notty was brand new and was in date and properly stored.

My hydrometer is the one I have always used with no problems. When I compared it to another spare hydrometer, the spare read .002 lower. (which means it read 1.023 for the stout at 2 weeks after pitching vs. 1.025 for my regular hydrometer) I am averaging the two readings now.

Sure is confusing at this point

Based on your reported process the only things that come to mind for the second batch is, what are the amounts of Crystal malt used in the recipe and possible mash temp issues. I know it not much help, but I think 4 packs of Notty should be fine.

It sure sounds to me like you mashed a lot higher than you thought you did. Notty is like a jack hammer on your wort. For it to not attenuate, you must have had a lot of unfermentables. I suggest calibrating your thermometers!

Are you re-hydrating the yeast in warm water before pitching? When dry the yeast cell walls are unable to regulate what enters the cell so if you throw it in the wort dry you will end up killing a bunch of yeast. Re-hydrate for optimal results.

sleepystevenson said:

The last two batches I have made with Nottingham for simplicity as it was the first times using the new brew system, I didn't want to complicate things further with liquid yeast.

Click to expand...

Notty has always been a good attenuator for me, and it will keep working all the way down near 54 degrees so fermentation temp was not the issue. I don't know what your new brew system is but I'd make sure you didn't mash at a higher temperature than you thought.

I have fermented with Notty at a fairly low temp and had no problem with it at all. I'm with conpewter, you might want to look at how high you are mashing.

Thanks for all the input, guys.

I really think that the low temps stopped the first batch of the Bee Cave Pale Ale variant. After the first couple days, the temp got as low as 50-52.

The one thing I foolishly didn't do (either batch) was re-hydrate the yeast.... just dumped 'er in... kinda keeping in Ed's Bee Cave Haus pale ale tradition....KISS...

As for the mash temps, the 3 dial thermos (1 each on HLT, MLT, BK) all were within 1 degree of each other and right on at boiling temp calibration.

I mashed at 152 and kept it pretty much in that area. I only used the direct fired recirculation MLT setup on a very low flame, and only used it when the temp fell 2+ degrees below the intended sac. rest temp. (I think I only used it one time during the mash, only for about 5 minutes, - and then again to raise the temp to 168 for mashout.) I don't see how the temps could have been off enough to make such an unfermentable wort....

From now on, I am definitely gonna rehydrate dry yeast!

I never had this problem with the old Ice Cube cooler mash tun! However, I never used dry yeast before either. I am trying to nail down the variables to figure out exactly what is happening. I guess I better keep brewing! My next recipe (A hefe) uses liquid yeast. So, we will see how that goes....with a big mother of a starter!!!

EDIT - Forgot to mention, I did use Wyeasts Yeast Nutrient in the boil, per my usual procedure.

Pics of the system are in my gallery.

Also,the stout recipe was a variant of O'Flannigans Dry stout, which I have always had good luck with before:
66% American 2 row
11% flaked barley
9% carapils
8% roasted barley
5.5% chocolate malt
37 IBU's Golding hops

just pitching the yeast on the wort should work. Did you brew both of these from the same sack of grain? It is a long shot but perhaps you got grain that has more protein than normal, I'm not sure what else would have caused this, you've covered a lot of the variables.

Yeah, really strange....

The grain came from two different sacks. (takes almost a full sack per brew now.) Both Breiss American 2 row. (which is my standard 2 row, always used without problems.)

Guess I'll just have to log a few more brews on this new system to get the kinks out. I was really hoping for good luck with the Notty, as a lot of people around here seem to like it. Also, it's SOOOO much easier than making a liquid yeast starter big enough for 24 gallons of wort!!! But, next time, I am gonna have to go the giant starter route anyway for the hefe.... so we'll see how that goes!

Going home for lunch now....gonna shake the fermenters and see if I get any action......!