Cargill's German Saltzgitter Pilsner malt attenation

[brewinhard]

So, earlier this year, I won a free sack of grain from Cargill's. And with wanting to do a run of german lagers (and a few summer belgians), I decided to try out their new German Saltzgitter pilsner malt.

I have used it so far in a small % in an American Blond ale and enjoyed the it. But finally got to use it to the tune of 86% in my latest Munich Helles. I mashed at 149F/90 minutes along with WL 833 and the beer fermented down to a very low 1.005 FG.
My thermometer is properly calibrated and the last Helles I brewed earlier this year finished at 1.012 with Bestmalz pilsner and WY Munich lager strain mashed at 150F.

So, a 7 point increase in attenuation with 2 main variables - yeast strain (WL 833 vs WY 2308) and base malt (Best vs Cargill). I still am confused why this took place. Any thoughts?

I will be giving the latest helles another week to lager prior to carbing it up and sampling to see how dry it really tastes at 1.005. I am hoping to pleasantly surprised. OTOH, the latest 2015 BJCP guidelines allow for Helles FG's to finish as low as 1.006, so take that with a grain of salt.

I also currently have 4 other beers fermenting with this base malt and am looking forward to seeing the FG's on those simply for comparison.

[NateBrews]

I used 2308 a lot before switching to 2124 and I never had it attenuate like that. My helles and pilsners were similar grist and mash temp (with weyermann pils malt) and I always had it end at 1.010-1.012.

[brewinhard]

It wasn't the 2308 I had an issue with. It never really "over-attenuated". The helles I just brewed with a 1.005 FG used WL 833 (which I also have never had attenuate that low either).