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Cooling Jackets for fermenters

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Hi,

My first post here, so if it is in the wrong forum, moderator please feel free to move it to correct forum.

I was wondering if folks here use jackets (like used in breweries) to control their fermenters' temperature. We are looking to set up a distillery to make single malt whisky and one of the options I am looking at is square stainless steel totes as fermenters. These come with a dimpled jacket on one side, and I am wondering if that'd be enough.

This will be located in Northern California, and the summer can get quite warm.

Cheers,

Virag

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The size of your ferment is an important indicator if you need a jacket. Also your ambient climate in your production space. Is it climate controlled? That's more of an issue of ferments getting cold during the winter and being too slow. If you're in a hot climate you run the risk of overheating during summer.

We work in 300G batch ferments atm and I've heard through the grapevine that around 300G is when you need to seriously consider cooling. Any bigger and you definitely want jackets. We use square tanks with jackets that keep our ferments below 90 deg F. We also ferment in bulk tanks with no jackets. The jacketed ferments consistently yield more per batch by maybe 3-5%.

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Temperature of your ferments are critical for good yield both potential and type. even a five gallon wash can over heat and yield bad alcohol. Cooling capabilities are a must in my book

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Temperature of your ferments are critical for good yield both potential and type. even a five gallon wash can over heat and yield bad alcohol. Cooling capabilities are a must in my book

Or heating, depending on one's geography and time of year.

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The size of your ferment is an important indicator if you need a jacket. Also your ambient climate in your production space. Is it climate controlled? That's more of an issue of ferments getting cold during the winter and being too slow. If you're in a hot climate you run the risk of overheating during summer.

We work in 300G batch ferments atm and I've heard through the grapevine that around 300G is when you need to seriously consider cooling. Any bigger and you definitely want jackets. We use square tanks with jackets that keep our ferments below 90 deg F. We also ferment in bulk tanks with no jackets. The jacketed ferments consistently yield more per batch by maybe 3-5%.

Thanks for your reply. We are planning 15 bbl batches (about 473 gals) in 550 gal tanks. Area won't be climate controlled, but my concern is more about the wash overheating, specially in summer.

Is your jacket on just one side or multiple sides of the tank ?

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Temperature of your ferments are critical for good yield both potential and type. even a five gallon wash can over heat and yield bad alcohol. Cooling capabilities are a must in my book

I agree. The temp changes can change the ester profiles, leading to an inconsistent product at the least. But I am trying to understand if single sided jackets are working for people using square totes.

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We run 530g in a 600g tank, and active cooling is absolutely essential. Without cooling the ferment will rocket to the mid 90s, even with a mid 70s pitch temperature ... and this is with a relatively cool "summer" temp - maybe 70-80f indoors.

The total heat load isn't tremendous, but the mash really wants to hold in that heat, especially when it is close to ambient. I would guess 2000btu/hr on your 15bbl for the first 48hr, dropping from there. On our system, the cooling doesn't run on once you pass the mid-point of the fermentation - but our ambient temperatures are generally lower than the fermentation temperature.

The geometry isn't ideal, which is probably giving you some heartburn, but the surface area is probably more than sufficient considering you are roughly 20% of the total surface area. A slight amount of agitation during fermentation (on a timer, sporadic) would minimize any temperature gradient.

Assuming you are talking about Custom Metalcraft. Give them a call and ask for references.

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James,

Thanks for a very informative response. Your read my mind. We've indeed been talking to Custom Metalcraft :) and will ask them for references. I was using 15 bbl x 15 brix = 225, and then multiplying it by 280 btu/brix, to get 63,000 BTU. So 1-2000 btu/hr for the first 48 hrs seems right on the money. The surface area seemed sufficient, but wasn't sure if agitation is needed.

Sorry for the late response, but just discovered that the lead time on stills is 6-9 months from most vendors so been chasing alternatives.

We run 530g in a 600g tank, and active cooling is absolutely essential. Without cooling the ferment will rocket to the mid 90s, even with a mid 70s pitch temperature ... and this is with a relatively cool "summer" temp - maybe 70-80f indoors.

The total heat load isn't tremendous, but the mash really wants to hold in that heat, especially when it is close to ambient. I would guess 2000btu/hr on your 15bbl for the first 48hr, dropping from there. On our system, the cooling doesn't run on once you pass the mid-point of the fermentation - but our ambient temperatures are generally lower than the fermentation temperature.

The geometry isn't ideal, which is probably giving you some heartburn, but the surface area is probably more than sufficient considering you are roughly 20% of the total surface area. A slight amount of agitation during fermentation (on a timer, sporadic) would minimize any temperature gradient.

Assuming you are talking about Custom Metalcraft. Give them a call and ask for references.

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We have 550 Gallon Metalcraft fermenters with cooling jackets on two sides adjacent to each other (really one big jacket). I had them also install a SS bushing for our RTD (about halfway up one side of the tank) which feeds back to our Chilled Water control system. Solenoid valves control the flow of cooling water to the jacket. Even without agitation during fermenting the cooling jacket surface area is sufficient to keep the ferment at the set temperature.

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Thanks Sonny. Why did you decide to go for two sides rather than one. Do you think just one side wouldn't have been sufficient. ?

We have 550 Gallon Metalcraft fermenters with cooling jackets on two sides adjacent to each other (really one big jacket). I had them also install a SS bushing for our RTD (about halfway up one side of the tank) which feeds back to our Chilled Water control system. Solenoid valves control the flow of cooling water to the jacket. Even without agitation during fermenting the cooling jacket surface area is sufficient to keep the ferment at the set temperature.

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Amount of GPM needed from your chiller system will be small, but you will need to run the chiller when not running the rest of your equipment, otherwise the fermenting action being exponential as far as heat rise, you will need cooling during the entire time of it.

Another good reason to have a water reservoir for your chiller, it will keep the chiller from short cycling, on and off, with only the small load of fermentation in the cooling loop.

Mike

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Thanks, good point about needing to run the chiller when other equipment is not running.

We were planning on a large chilled water tank anyway so a we could cool 450 gals of wort with a smaller chiller sized more for the stills.

Amount of GPM needed from your chiller system will be small, but you will need to run the chiller when not running the rest of your equipment, otherwise the fermenting action being exponential as far as heat rise, you will need cooling during the entire time of it.

Another good reason to have a water reservoir for your chiller, it will keep the chiller from short cycling, on and off, with only the small load of fermentation in the cooling loop.

Mike

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