Grain on/off single malt ferment?

[Bakery87]

Howdy from Texas!

We're looking at producing our first single malt and originally planned on a grain-off fermentation.  We've been making our way through rye and bourbon so far without many issues and handle both of those as a grain-on ferment/distillation.  We do have a false bottom on our cooker and have the ability to lauter, but eyeing how easy grain-on ferments are, should we be keeping our single malt the same?  My concerns primarily lie with the astringency that can occur from taking barley to too high of a temperature.  This wouldn't happen in our cook, but would occur in the distillation process.  By that time all sugar should be extracted and converted, but I figured the astringency would come from other parts of the grain that don't contain the sugar we so desire. 

 

Thanks everyone,

Mike

[Silk City Distillers]

I’ve been running 100% malt barley through a hammer mill, fermented and distilled on grain.  No astringency.  Try it for yourself.

[SlickFloss]

I got multiple awards on two malts single pass column distilled grain in. There’s so many other astringent chemicals created in distillation as well as other noxious ones etc, it’s your job as a distilled to cut those chemicals out. So what works for you, but you’ll see a slight but not sinignificant yield increase grain in. Plus, depending on adjuncts/cook method, good luck lautering!

[kleclerc77]

If I had the ability to lauter, I would. Why not use the equipment to its potential? @Silk City Distillers - are you getting a pretty fine flour from the hammer mill? We have been considering doing a single malt here (no lautering capability), but I can't imagine working with/pumping the roller milled stuff that was crushed to be lautered. The small percentage we use in other recipes already forms quite the brick on top of the ferment after ~12 hours or so. Maybe with a finer grind, it would be more doable though.

[adamOVD]

I haven't done identical mashes on/off grain, to do a true comparison, but I have distilled on grain malt whiskeys, and have had batches lautered for me by a brewery. I would not call the on grain batches any more astringent or tannic than the distilled beer. One benefit of the beer is the low wines are almost clear first run and don't make much of a mess to clean. Whether or not that also leads to a cleaner tasting product, I don't know, but I would guess it does. The biggest down side of lautering in my opinion is, depending on how efficient your mash tun is, and how big your grain bill is, you're leaving a lot of sugar behind. Probably around 10-20% even with a properly sized mash tun.

Pumping out the fermenter isn't any harder than a wheat mash for me, and I have flat bottom fermenters not conicals. I'm not using a roller mill though and have heard that they aren't great for on grain since they don't shred the husk.