Peculiar fermentation - 1084 Irish Ale

I recently make the NB Breakfast Stout AG recipe, which calls for the 1084 Irish Ale yeast. It was my first time using this yeast. I pitched it straight (no starter; OG was < 1.040), the wort was well-aerated with O2, and included a teaspoon of yeast nutrient. Fermentation started close enough to on-time, but when it was finally at high krausen, the krausen was different than my past experience.

It was never very thick… maybe 3/4" (for a 6.5g carboy), and it fell back into the wort within about 2 days. Fermentation was in my basement, which was cold, but the stick-on thermometer read > 62-64 until the fourth or fifth day after pitching; most times the thermometer read about 66. Concerned about a stuck fermentation or too-cold temps, I put a brew belt on it about a week after pitching and (accidentally!) let it get up to 78, though also without any noticeable activity.

Does anyone have any experience with this yeast to say whether or not this is normal activity for this yeast?

I have the NB Dry Irish Stout finishing up right now using the 1084. I pitched (accidentally) at 58F and it never got above 61F. However, it also almost blew my airlock out. Krausen went to the top of my 6 gallon carboy with 5 gallons of beer in it.

I have made NB’s Dry Irish Stout with wyeast 1084 and i had the same results as you Silentknyght my krausen lasted for 1 day and it settled and it seemed like nothing else was happening. My fermentation temp was at 72 degrees and it never went any higher or lower. I let it sit for about 4 weeks in primary then racked to keg and carbonated… IT WAS THE BEST STOUT EVER.
My advice is just to let it do its thing and give it time, although i did make a cream ale with wyeast 1084 and it almost blew the top off of my carboy too, a six gallon carboy. When i pitched the yeast from a .6 L starter it was at 72F and fermentation activity and high krausen it was at 76F, after krausen fell it churned for days at 73F and decided to settle down 5 days after krausen. Anyways I was trying to figure out whether the hissing noise at 5:30 AM was a leak in my kegerator compressor or what, turns out my 3 piece airlock was filled with krausen and hops particle and was about to shoot sky high.
Silentknyght once again just let it sit for NB’s total recommended time or longer. I’m also going to make a 5 gallon NB’s Irish Red Ale with wyeast 1084 in a 1.5 L starter. I’ll post back how my fermentation is if this thread is still on top if not i’ll PM you.

I used 1084 on the same stout recipe, 2 weeks apart. The first one seemed dead after 1 1/2 days. The second one took off like a rocket and was crazy for several days. Both turned out fine.

I never worry about the amount of krausen. I have used the same yeast in similar, but not the same, recipes and have gotten a little krausen in one and a lot in another. I feel there is no reason for concern unless I think the gravity is not dropping as expected. This has not happened to me yet. Knock on wood. 12 brews since July 1.

I have an Irish stout planned for the beginning of feb that I am thinking about using 1084 on. My question is my brew room is in the low 60s this time of year, how would that effect this yeast.

Yesterday I made a Irish Red Ale with 1084 with an OG of 1.044 and using a 1.50 L starter. My stick on themometer says its at 67F and it is at high krausen right now. It is bubbling away like a champ, Wyeast recommends the temp range from 62-72F so you seem to fit right in there. Yeast is much more hardy then we give it credit for and even if your temp drops to 60- for the night i’m sure it will be perfectly fine.

Okay 5 days after brewing my Irish Red Ale using wyeast 1084. I used 1.5L starter which started to show activity 10~12 hours after pitching, and then the krausen lasted for about 2~3 days. it stopped bubbling 1 day ago but it only bubbled once every 5 minutes. I have kept it consistently at 70F. I remember using Safale-05 for my Irish Red and the krausen stayed on that for 5 days and it kept bubling every minute. I guess different yeast have different activities.

Sounds fine to me. I’ve always had good luck with it using a starter and keeping temps low.