Blending and diluting tank/vessel for small but professional distillery

[Pyrate]

Hey Guys,

I am sitting here in Germany looking for a tank that allows me to blend and/or dilute about 500 to 1.000 Litre of product in one go. But honestly it seems very hard to get the right fit.

Most of the time I want to use the tank for dilution (e.g. Gin-Distillate from around 85 %ABV to 40-50 %ABV) and blending of sweet spirits (GNS, water, sugar, distillates etc.). 500L capacity is good, 1.000 would be nicer. Maybe something in between.

Every recipe depends on weight. ABV dilution is also depending on weight. Hence, I need a scale/weighting solution for the vessel too.

An agitator is mandatory. It has to be explosion-proof (EX1).

And I want to be able to move the tank in our warehouse (forklift for example).

Best case would be if I can use the tank also to store/rest distillates for a few weeks up to several months. The agitator has to be dismantled for storage. In that case I would buy a few tanks and one agitator.

Whats charming about this solution is that you have your distillates in the same vessel as your product until you bottle it. No need to pump stuff from a storage vessel to a blending tank and back...

I look at the Speidel selection. They have tanks which can be carried by a forklift. But since the platform is PE and not steel there is a problem with electrostatic charge. Officially they do not sell these tanks for inflammable spirits. On the other hand, there are professional distilleries using these exact vessels for moving and storing their fresh distillates...

So, after writing all this, maybe some of you have a recommendation for me. What is your blending/diluting setup?

Thank you guys!

 

[Silk City Distillers]

If you plan to have multiple tanks, it's going to be far easier to just get a standalone EX pump and use that to recirculate to mix, since you'll probably have one anyway.

Something like a Letina closed top forklift tank or similar is probably the easiest to use from a workflow perspective.  There are a number of companies that make iso or equivalent 1000l shipping tanks that could be easily repurposed (like a stainless IBC).  Many of these are made to fit a standard pallet footprint, meaning they'll easily fit on a pallet scale.

Agitators add lots of complexity, especially to thin wall wine-style tanks that are not built to handle the weight and stress of an agitator.

 

[Pyrate]

@Silk City Distillers thank you for your insights. But I don't understand the way to blend/mix/dilute my spirits and liquors with an EX pump that you recommend. Can you explain it a bit more in detail?

[PeteB]

attach suction of pump to bottom outlet of tank, feed output into the top of tank. If outlet is above the liquid in the tank it will create a lot of bubbles that will assist in mixing. Also if pump outlet is at an angle it will swirl the contents and help with mixing.

What is wrong with a simple canoe type paddle? 1,000 litres is not hard to mix that way.

[Patent5]

On this note - how do gin distillers store their gin.  We a few plastic IBC totes where we store our gin @ about 60% and take it out to proof as needed.  I worry about storing in plastic and worry the gin loses its flavor if sitting in a tote more than a few months.

[Silk City Distillers]

What Pete said - These tanks typically have multiple ports.  Drain port at the bottom and often one or two additional for racking or sampling that can be used to recirculate.  

 

 

[Pyrate]

Thanks @PeteB and @Silk City Distillers for the explanation. I get it and I think it should work for dilution (distillate/alcohol plus water). But does it work properly for sweet liquors? Have you tried it?

Right now I am doing the paddle thing with <100 Liters. And solving the sugar sirup for our sweet liquors is a pain and I always doubt that its solved/mixed properly. I can't imagine doing it for 1000 Liters. And you need a big paddle and a big manhole in the top of the tank.

Besides the agitator issue: I also want to weight the tank during blending/mixing/diluting. Have you suggestions for that? Do you guys care much about electrostatic charge as explosion hazard?

Thank you for any further help!

[Pyrate]

@Patent5 somehow it feels wrong for me to store any distillate/product in plastic...

[Thatch]

16 hours ago, Patent5 said:

On this note - how do gin distillers store their gin.  We a few plastic IBC totes where we store our gin @ about 60% and take it out to proof as needed.  I worry about storing in plastic and worry the gin loses its flavor if sitting in a tote more than a few months.

IBC's may not be used for storage, they are only for shipping.  https://www.dalkita.com/prohibition-on-flammable-liquids-in-plastic-totes/

[Silk City Distillers]

There are plenty of guides to bonding and grounding available, find one applicable to your jurisdiction.  The principals are broadly applicable, this isn't something unique to spirits.  For example:

https://www.justrite.com/media/2019_Justrite-Guide-to-Safe-Grounding-and-Bonding-Practices.pdf

Stainless IBC usually have 16-18" manways.  1000l ibc are manageable from the manway, any larger and it becomes difficult without a ladder or steps.

[Thatch]

7 minutes ago, Silk City Distillers said:

Stainless

He wrote plastic "We a few plastic IBC totes"

 

 

[Silk City Distillers]

3 minutes ago, Thatch said:

He wrote plastic "We a few plastic IBC totes"

I keep trying to nudge the conversation to stainless.

[Pyrate]

After some hours more research I am back.

Some of the people here in the forum are using open stainless steel tanks with big volumes (I guess 500 or more liters) without any top to mix their spirits with a paddle. Is it just me or is that method a bit risky because of the alcohol vapors?

Since you guys recommend the pump in circulation method, have you used it to solve/mix sugar (sirup) for sweet liquors? What are your steps? I guess you start with weighting and adding of the components in the tank (spirit, add water and maybe sugar etc.). After that you attach the pump to mix?

Does the tank need a ventilation or can you pump in circulation in a closed system? I am thinking about pressure...

Thank you for more help!

[glisade]

I use a ~400 liter stainless steel drum to proof and mix my liqueurs for bottling. It has a lid but yes its essentially open top and I just use a stainless steel pale to mix everything. Usually after multiple mixes, everything is uniform in about 24 hours. It sits on the proofing scale on top of a pallet so I can move it around later or onto the forklift if I need to filter it into another drum. I don't like using pumps to circulate or move spirit from drum to drum since you can lose product in the hoses and pump and then you have to clean everything after. If you have a forklift, gravity is more efficient with less clean up.

[Southernhighlander]

We have stainless tanks, for blending and proofing.  We can supply the tanks with explosion proof agitators or explosion proof pumps.  We add grounding terminals so there is no chance of static discharge.  Our blending/mixing tanks are in several distilleries.  For a quote and reference list email paul@distillery-equipment.com

 

[Pyrate]

@glisade

Do you care about grounding and electrostatic charge?

And your Mixing Power is muscle only?

I love gravity too and also Not changing tanks/vessels if Not necessary. Do you have any safety meassures in place when you let spirit flow from a lifted tank to an other tank? Do you use hoses/pipes or do you just open a tap/faucet and let the stuff Flow into a manhole?

[glisade]

52 minutes ago, Pyrate said:

@glisade

Do you care about grounding and electrostatic charge?

And your Mixing Power is muscle only?

I love gravity too and also Not changing tanks/vessels if Not necessary. Do you have any safety meassures in place when you let spirit flow from a lifted tank to an other tank? Do you use hoses/pipes or do you just open a tap/faucet and let the stuff Flow into a manhole?

I don't worry about grounding. The drum should be grounded on the concrete or proofing scale. When on the wooden pallet, I still don't see much concern. But, as you say this is a stainless steel paddle in a stainless steel drum. So there isn't all that much movement and vapor being pushed up like potentially with a mixer, just muscle slowly sloshing everything around. I'm sure you could put a ground strap on it though and tie it to a set point when on the scale.

I just have a drum on a pallet and lift with fork lift or a drum directly on the forks. Depending on the size of the drum, I may strap it to the forklift. I use tri-clamp fittings from the bottom valve of the upper drum to flow or filter into the bottom drum. Right now I have a 100 gallon plastic cone bottom tank that's bolted to a mini-pallet in the air with the forklift. I am transferring the liqueur through a 1 micron bag filter into a 100 gallon stainless drum on the proofing scale. I strapped the tank to the forklift so I can tilt it forwards to get all the product out. All I have to clean afterwards is the tank and a few tri-clamp fittings.

I've done it like this for 5 years without any issues.

[Pyrate]

Thank you @glisade for the detailed information. You don't have any pics to show your setup/drums?

Offtopic: Guys I really enjoy discussing this stuff with you. Here in Germany there isn't much of a community of distillers etc. They make a big secret of everything and usually are not open to share insights... Therefore, thank you!

But one thing remains not clear to me: do your approaches work for sweet liquors where you mix/blend sugar/honey or something else that doesn't mix as easy as spirit plus water? Have you tried that?

[glisade]

Message me with your email and I can send some pics. And I make various liqueurs with my setup.

[Pyrate]

Hey Guys, I am still working on the mixing / blending vessel solution.

I have a new question: you recommended the use of a circle pump instead of an agitator. But one issue seems to come up with that: how do you make sure there is no product left in the pipes and the pump after mixing? Isn't it a additional issue to clean that stuff etc. compared to an agitator?

Thank you for your additional insight!

[MoonshineWillie]

Hi Pyrate!

I work at a craft distillery in New England (USA), making lots of different cordials and gins.  We use almost every sweetener available.  Our tanks are 320 and 620 liter Letina tanks with variable capacity lids.  Man power (paddle) or a spirit pump is what we use to mix and blend.  The trick with sugar we have found is to use a very finely ground product, and to draw off a few liters at a time into a bucket and mix with a small amount of sugar until it is dissolved.  Then repeat that process until all of the sugar is added.  

Cheers!