Mash Tun to Fermenter Volumes: Whiskey Production

[TheLazyWombat]

G'day Folks, 

Greetings from the Land Downunder! I'm looking at setting up a commercial distillery at the moment and one of the products on the range is a whiskey... I'm working out equipment specifications and looking at a 1500L working volume fermenter... I'm wondering what the ideal volume would be for a mash/combi tun? I don't want to be doing multiple mashes to fill the fermenter and nor do I want to be producing too much wort and want to ensure I have enough volume to run a suitable sparge volume. 

Cheers

LazyWombat

[Beerideas]

Wouldn't it be easier to work backwards through your still size to determine batch volumes after a stripping run?

 

[adamOVD]

What do you want your Starting gravity to be? The higher you want your gravity to be, the more grain you will need, and the bigger your mash tun needs to be. Are you purchasing your equipment from someone? They should be able to size your equipment accurately for you. I'd guess most people that lauter have, at an absolute minimum, a mash tun 1/2 the capacity of their desired quantity of wort. Are you going to use it for anything other than lautering, or are you ever going to ferment on the grain? If so you might want one the same size as your fermenter. 

[kleclerc77]

I like our 1:1 mash tun to fermenter size. Keeps things simple. That being said, it would be pretty badass to have that ratio be 2:1 so you could fill both fermenters with one mash. I don't see any advantage in having a mash tun that won't fill at least one fermenter.

[TheLazyWombat]

8 hours ago, kleclerc77 said:

I like our 1:1 mash tun to fermenter size. Keeps things simple. That being said, it would be pretty badass to have that ratio be 2:1 so you could fill both fermenters with one mash. I don't see any advantage in having a mash tun that won't fill at least one fermenter.

But would it not depend on what your sparge volume was? Is there an approximate mash to sparge water volume? I know it all depends on your SG target/grain bed depth but if you had a nice deep grain bed in, say, a 750L, or 1,000L, tun would it be impractical to mash/sparge 1500L through? I certainly wouldn't want to do multiple mashes to obtain the 1,500L wort to fill the fermenter 

[kleclerc77]

Oh yeah nah we do all grain in stuff here. No lautering capability so no malt whiskies for us at the moment.

[Silk City Distillers]

Slightly off topic, but I have done a few runs now of hammer milled grain-in malt whiskey, and I was very, very pleasantly surprised with the flavor of the distillate.  Give it a go, you might like the result.  I generally go out of my way to try to challenge the status quo.  I continually hear that you can't make malt whiskey grain in.  So I said, that sounds like the perfect thing to try out.  Tannin astringency?  Huh?

We tried roller mill variants, that created real headache in pump overs from the tun to the fermenters, from the fermenters to the still, and on still cleanout.  Roller milled malt wants to self-lauter everywhere possible.  Flavor wise, roller vs hammer was identical, and hammer transferred like a traditional grain-in mash/wash.

I think this "myth" has more to do with process implications and traditional production methods than distillate flavor implications - dealing with large volumes of roller mill barley is very difficult grain-in.  I can absolutely see why someone wouldn't do it that way.

We are next door to a brewery, and have distilled similar mash bills on our equipment, so we are familiar with the flavor profiles.  I think this is important, you need to do this comparison on your own equipment to have any real idea.  Comparing two different whiskies from two producers and attempting to attribute the difference solely to in vs out ... not possible.  I don't discount the fact that there are probably a lot of terrible craft malt whiskies made grain-in in the US, that are probably terrible for a host of reasons, the least of which is grain-in.

Maybe I can make everyone mad with this last point.  I've found that UK-sourced malts result in a flavor profile far closer to UK malt whiskies than using US/Canadian grown pale brewers malts.  Running a batch of malt whiskey using Baird's pot still malt was an epiphany compared to grain-in/grain-out.  I mean, pull a chair up to the parrot epiphany and sit there with your head in your hands wondering how the hell it could be so much better.  I'll never make a malt whiskey that doesn't use a UK pot still malt again, it's that shockingly better.  Even worse, using high enzyme "distillers" malt for any portion of the mash bill, blech, high DP malt is awful, avoid it if you can.

Ran a batch last week using 60% of the Inverness heavy peated malt.  I was like a giddy schoolgirl.

[JustAndy]

20 hours ago, kleclerc77 said:

I like our 1:1 mash tun to fermenter size. Keeps things simple. That being said, it would be pretty badass to have that ratio be 2:1 so you could fill both fermenters with one mash. I don't see any advantage in having a mash tun that won't fill at least one fermenter.

I can't see the logic for having a mash tun 2x the fermenter; unless you are distilling 2 fermenters at a time it would mean you have one sitting empty while waiting for the other before you could mash. A half-full fermenter will often work fine, a half-full mash tun or mash mixer might not depending on the placement of agitator, steam jacket, rakes, etc. 

[kleclerc77]

3 hours ago, JustAndy said:

I can't see the logic for having a mash tun 2x the fermenter

The production schedule we're on now has me mashing twice a day to fill two fermenters, so for our situation an oversized mash tun would be sweet. Mash twice and clean the still Wednesday, polish Thursday and Friday, strip Monday and Tuesday, and repeat. Everyone's setups are so different it's hard to generalize about equipment needs

 

Also, I love the hot takes @Silk City Distillers ! We are collaborating with a brewery to lauter some single malt wash for us in the coming year because of the horror stories of on-grain single malts. Have you considered doing that with the brewery next door? My biggest fear would be the (in)ability to get all the malt our of the fermenter after a nice long ferment.

I've heard the same high praise about UK malts. Does it justify the price difference? 

[SlickFloss]

On 8/31/2020 at 3:18 PM, Beerideas said:

Wouldn't it be easier to work backwards through your still size to determine batch volumes after a stripping run?

 

yes. it would.

[JailBreak]

I know this is going to rub a lot of people the wrong way but I'm always surprised at how many people seem to either not read the OP's post or not read it close enough. There's like two responses on this entire thread that actually provide helpful information to the OP's question. That being said @adamOVD is right on the money with his post. At minimum you would want 1/2 the size in a combo tun. It honestly doesn't hurt to go bigger though, for higher gravity mashes. For a 1500L fermenter, ruling out the on-grain fermentation later, a mash/lauter tun of 1000L should be able to do everything you could possibly throw at it.

[TheLazyWombat]

On 9/24/2020 at 12:58 AM, JailBreak said:

I know this is going to rub a lot of people the wrong way but I'm always surprised at how many people seem to either not read the OP's post or not read it close enough. There's like two responses on this entire thread that actually provide helpful information to the OP's question. That being said @adamOVD is right on the money with his post. At minimum you would want 1/2 the size in a combo tun. It honestly doesn't hurt to go bigger though, for higher gravity mashes. For a 1500L fermenter, ruling out the on-grain fermentation later, a mash/lauter tun of 1000L should be able to do everything you could possibly throw at it.

Thanks JailBreak, I do appreciate your very helpful response and guidance. 

[adamOVD]

On 9/2/2020 at 3:45 AM, Silk City Distillers said:

Slightly off topic, but I have done a few runs now of hammer milled grain-in malt whiskey, and I was very, very pleasantly surprised with the flavor of the distillate.  Give it a go, you might like the result.  I generally go out of my way to try to challenge the status quo.  I continually hear that you can't make malt whiskey grain in.  So I said, that sounds like the perfect thing to try out.  Tannin astringency?  Huh?

Older post, but I was shopping around for a new mill, and stumbled on this. Are you also distilling on the grain, or separating post fermentation?

[Silk City Distillers]

Distilling on grain.

[adamOVD]

Thanks. I been putting off trying to make an American Single Malt for the reasons you mentioned, but really want to give it a go.