Safale US-05 Attenuation

[JoeBrews]

Hi all,
We've been using Safale US-05 here for quite some time and in the past few months have noticed a tendency for extremely high attenuation. I've made sure all my thermometers are calibrated and tried different mash temps (infusion mashtun) as well as mash thicknesses, and I've been repeatedly getting attenuation rates around 85%. I do not recrop and ferment at 68 degrees generally. Just 3 months ago or so we were consistently getting rates of 75%. Anyone else noticed this trend or anything similar.

Thanks in advance,
Joe

[tnknight]

The past couple of batches I have noticed an attenution of 78%, when the previous ones this fall were closer to 75, 76. I haven't worried about it, but I can understand your concern with AA at 85%. I recently did an imperial stout, 20 Plato, and got an 80% attenution on that. I slightly underpitch, 500g per 10Bbl batch of 13.5 plato pale ale. I mash between 152 and 154 and ferment at 67.

[JoeBrews]

Interesting, my parameters are almost exactly the same... 15.1P IPA mashed at 152-154 at 68 with a 500g pack to 10bbl and it finished at 2.0 (86%aa). I'm kinda stumped.

[tnknight]

Hmmm, those numbers stump me too. I would suggest contacting crosby and baker or whomever your supplier is and telling them about your numbers and working out possible solutions. Fermentis boasts a strong customer support committment on their site. I have never contacted them personally, but no place better to inquire than the source.