Abysmal efficiency with spelt malt

[SRJHops]

I usually get 68-70% mash efficiency, but yesterday I brewed a saison with 35% spelt and the efficiency was a shockingly low 59%. I'm still on track for a tasty -- albeit lower ABV -- saison, but it's got me stumped. Has anyone else had this problem?

Mash ph was 5.15, so that would not seem to be the trouble. 60 mins at 151. In hindsight, maybe 90 would have helped.

I wonder if the crush was the issue? The spalt grains do look small/odd... I crush at the LHBS and it has never been a problem. But maybe I should run the spalt malt through twice or something?

 

[VikeMan]

I assume you mean Spelt.

Yes, spelt malt, like regular wheat malt (and maybe even moreso), has small kernels compared with barley malt. The perfect mill gap for barley will be to wide for spelt, resulting in a poor crush and lower efficiency.

 

[SRJHops]

I assume you mean Spelt.

Yes, spelt malt, like regular wheat malt (and maybe even moreso), has small kernels compared with barley malt. The perfect mill gap for barley will be to wide for spelt, resulting in a poor crush and lower efficiency.

Ooops yes, spelt. (I'll see if I can edit that!) So it sounds like you would suggest I at least run the spelt through twice? I can't really change the crush at the LHBS. Or maybe I can ask them to adjust it for me... It is always set and can't be moved, or so I've always thought.

 

[VikeMan]

Ooops yes, spelt. (I'll see if I can edit that!) So it sounds like you would suggest I at least run the spelt through twice? I can't really change the crush at the LHBS. Or maybe I can ask them to adjust it for me... It is always set and can't be moved, or so I've always thought.

My first choice would be to change the gap. But if you can't, running the grains through a second time certainly helps.

 

[SRJHops]

My first choice would be to change the gap. But if you can't, running the grains through a second time certainly helps.

Thanks. Since I just use the setting they have at the LHBS, I don't know much about optimal gaps. Is there a resource you could point me to? Such as a list that shows the ideal gaps for different grains? Or is it more simple than that?

 

[VikeMan]

Thanks. Since I just use the setting they have at the LHBS, I don't know much about optimal gaps. Is there a resource you could point me to? Such as a list that shows the ideal gaps for different grains? Or is it more simple than that?

It's really not that simple. Lots of people will talk about ideal mill gaps, but a lot depends on the roller design, how worn the knurls are, etc. If you have the opportunity to adjust the gap at the LHBS, I'd recommend experimenting to find the point where the crush looks good.

Also, I'd recommend adding rice hulls if you weren't already. The finer crush increases efficiency, but can also gum up the lauter since the spelt malt is huskless.

 

[TheMadKing]

Did you measure or calculate your mash pH?

Spelt wheat malt has a high DIpH value which could have resulted in a higher than expected mash pH.

 

[SRJHops]

Did you measure or calculate your mash pH?

Spelt wheat malt has a high DIpH value which could have resulted in a higher than expected mash pH.

Yeah, my pH was actually a bit lower than target... It was 5.15. I don't think that was the issue.. pretty sure it was the crush. I emailed my LHBS and they said they would adjust the crush if I asked next time.

 

[DuncB]

Thank you for this info, I'll bear it in mind when I try this grain.
 I enjoyed spelt misspalt.