Have you guys experienced underattenuation problems with Lallemand Nottingham? My dry Irish stout has been fermenting for almost a week now and has been sitting at a stable 1.016 FG for 4 days. The yeast has completely crapped itself out and flocced in a tight cake at the bottom of my FermZilla. This is particularly odd, because I thought my grist would translate into a fairly highly fermentable wort, and I've also heard that Nottingham is a crazy attenuator:
70% MO
20% Chit Flaked Barley
10% Roasted Barley
Mash temp: 65c
Expected OG: 1.041
Expected FG: 1.010
Actual OG: 1.042
Actual FG: 1.016
I chilled the wort down to 18c, transferred the wort by draining it from the kettle to my primary from a quite tall height to get some aeration going in (so heavy splashing and foaming happening), aerated by giving it a few good splashes, and pitched non-rehydrated Nottingham. I then set the fermentation chamber to 15c.
I actually experienced the same underattenuation with my pressure-fermented pilsner (W3470) even though I pitched two packs into fairly low OG wort. It makes me think I either have oxygenation/nutrient issues or my LHBS is supplying old yeast.
Is there anything I can do to get it to finish drier? I know there will be answers stating "a week is too little", but remember that we are dealing with Nottingham here.
70% MO
20% Chit Flaked Barley
10% Roasted Barley
Mash temp: 65c
Expected OG: 1.041
Expected FG: 1.010
Actual OG: 1.042
Actual FG: 1.016
I chilled the wort down to 18c, transferred the wort by draining it from the kettle to my primary from a quite tall height to get some aeration going in (so heavy splashing and foaming happening), aerated by giving it a few good splashes, and pitched non-rehydrated Nottingham. I then set the fermentation chamber to 15c.
I actually experienced the same underattenuation with my pressure-fermented pilsner (W3470) even though I pitched two packs into fairly low OG wort. It makes me think I either have oxygenation/nutrient issues or my LHBS is supplying old yeast.
Is there anything I can do to get it to finish drier? I know there will be answers stating "a week is too little", but remember that we are dealing with Nottingham here.