Refrigerated bulk tanks- value

[mainebackswoodssyrup]

Anyone have any idea on what a working used refrigerated stainless steel bulk tank with an agitator would go for in the 500-1000 gallon range? I'm seeing anywhere from $2-$6/gallon with online ads. Trying to see what we should be looking for without over paying. Any input is appreciated.

[minehart gap]

I was pretty lucky when I found a 1000 gallon tank with refrigeration unit and automatic washer but no agitator and will have right about $1000.00 in it when it is installed and working at my sugar shack. I had to tear out a block wall and remove everything myself (I used the farms skid loader) and I hauled it. The farm was in the process of being sold to an Amish family that does not use electricity and I had a time limit right in the middle of maple syrup season. I am working on buying a 800 gallon tank with refrigeration unit and automatic washer right now but I am pretty sure that I will not get anywhere near as good of a deal.

[DrTimPerkins]

A good deal depends upon age and condition, size, availability, compressor specs and condition, and demand in your area. Working units are typically in the $2-5/gal range. Check Craigslist in your area. Frequently you’ll have to remove and transport it yourself unless you buy from a dealer.

[mainebackswoodssyrup]

Thanks for the info. Not in a rush for it, just one of those things I'm trying to keep an eye out for when a good deal is found.

[DrTimPerkins]

For us, adding a refrigerated bulk tank has been a real game changer. It has almost completely decoupled the RO concentration and boiling process. We may concentrate 20-25 times each season (to a very high value, usually around 35 Brix), but only boil 5-8 times each year. The concentrate is chilled to about 24 deg F (the temperature you can chill to without it freezing is dependent upon the Brix level), which can easily keep it fresh for at least 2 weeks. We have about 1,000 gal of refrigerated or insulated cold concentrate storage. Boiling usually is about once a week, is easy to schedule, and can be done during the day. We don't boil on weekends or at nights...the crew gets to go home. As a consequence, our vacuum system is tighter and thus our production is better.

The next couple of changes are:

1. Adding 1,000+ taps this summer/fall (with separate collection of red maple and sugar maple sap so we can check on sap volume, sugar, and syrup flavor differences, a Dr. Abby headed study).
2. Adding a pump line to eliminate the need to truck sap from a remote station.
3. Because of #1, we're adding another post to the RO and replacing our current 10" filter press with a 15" press.

[mainebackswoodssyrup]

Yes, I like the idea of the convenience. It will be especially handy once we get an RO and have concentrate we can store if we want. We spend thousands on evaporators, filter presses and RO's so a refrigerated tank seems like a worthwhile investment. I do know from talking with an HVAC buddy I know that repairs can get expensive quick though.

[minehart gap]

The concentrate is chilled to about 24 deg F (the temperature you can chill to without it freezing is dependent upon the Brix level

Dr.Tim, is there a formula to determine the freezing temperature of concentrate and if there is, would you please share it.

[DrTimPerkins]

Dr.Tim, is there a formula to determine the freezing temperature of concentrate and if there is, would you please share it.

Note that this is an approximation based upon a pure sucrose solution. The formula is embedded within the chart. There will be some variation based upon other substances in the concentrate (other types of sugars, organic acids, etc. Sap/concentrate will tend to freeze slightly lower due to these other inclusions. There could also be differences based upon how well your bulk tank is calibrated and whether it is continuously stirred. Bottom line is...the first few times you do this, keep checking it to make sure you don't end up with a huge concentrate-berg in your bulk tank. Slushy concentrate doesn't flow through evaporator feed lines very well. Better to keep it slightly ABOVE freezing than slightly BELOW freezing.

21468

[mainebackswoodssyrup]

Great info, thanks for sharing. Might go look at one tomorrow. Guy called it a double lined tank. I assume that means insulated or jacketed as other terms used? Seems to be worth quite a bit more. Not sure it makes much difference to me for holding sap in March/early April though.

[DrTimPerkins]

Great info, thanks for sharing. Might go look at one tomorrow. Guy called it a double lined tank. I assume that means insulated or jacketed as other terms used? Seems to be worth quite a bit more. Not sure it makes much difference to me for holding sap in March/early April though.

Typically there is an inner tank, with refrigeration built-in (mostly on the bottom), then insulation, then an outer tank.

https://www.youtube.com/watch?v=CXpZNVrdSo4

If you're not using the refrigeration unit, then it is basically just a HEAVY tank.

[minehart gap]

Thank you Dr.Tim. that chart will be very helpful

[Pdiamond]

I bought a 400 gallon milk tank today for my sap storage. Since I am a small producer this should work real well for me as it has two lids and will be so much easier to clean vs the 325 or 275 gallon totes. I do not plan on long term storage for my sap.

[Bucket Head]

Hands down, a working bulk tank is a very worthwhile investment! I got one operational 4 or 5 years ago. It takes the worry out of losing sap/concentrate due to a lack of time to boil. I only boil on the weekends now, which is when I have the time to boil. I gather and R.O. throughout the week. I would not be able to make much syrup by just boiling whatever sap ran on Fri. and Sat. and then boiling on Sunday!

My tank is a 500 gal. Mueller that I paid $500 for and the dairy refrigeration company's bill to get it working was $750. Maybe you can get it done for less, maybe it'll cost a little more- but it will be worth it.

Dr. Tim calls it a game changer and I agree. But it can also be called a game saver!

Steve

[mainebackswoodssyrup]

Ya, that's the kind of deal I would be looking for. That same tank you have, I'm seeing for closer to $3000 from online dealers. Still worth it in the long run but more than I'd like to pay.

[Bucket Head]

Yes, online and Craigslist ad's around here for "working" tanks are $3500-$8500. And I'm not saying they are not worth that- but I figured I could get one going again for less than that.

And don't think a non-working tank, or one that has a known leak somewhere, is not usable. My tank had a leak in it- it would not hold vacuum when tested. The refrigeration guy disconnected the leaky side of the tank and then only charged the other side. Yes, it only has half the cooling capacity as it did, but it does not take much cooling to bring 50-ish degree sap down to 34 degrees (my lowest temperature setting). Remember, these tanks were designed and built to bring 100 degree cow's milk down to 30-something in the middle of summer! They don't work too hard to keep sap cool.

Have a dairy refrigeration/refrigeration guy look at a tank you might have otherwise passed on first. You might be pleasantly surprised! There are a lot of tanks out there yet. And sometimes one comes up from a farm that just recently stopped operations or they needed a bigger tank. Those won't need much at all to get up and running again.

Steve

[n8hutch]

The Hard Part Can be Finding a good deal on a Compressor, I have a 1000gal tank with good coils, but I didn't get a compressor with it, I got the Tank for reasonable money but good compressors seem to be more than the Tank.

[minehart gap]

Might want to go to a few farm auctions.

[mainebackswoodssyrup]

The Hard Part Can be Finding a good deal on a Compressor, I have a 1000gal tank with good coils, but I didn't get a compressor with it, I got the Tank for reasonable money but good compressors seem to be more than the Tank.

That's what I found on the tank I looked at last weekend, needed a compressor. Wasn't such a good deal after all.

[DrTimPerkins]

...but it does not take much cooling to bring 50-ish degree sap down to 34 degrees (my lowest temperature setting). Remember, these tanks were designed and built to bring 100 degree cow's milk down to 30-something in the middle of summer! They don't work too hard to keep sap cool.

That is correct. Sap coming out of the RO might be a bit warm depending upon how hard you're squeezing it, but the air temperature is generally fairly low, so the compressor isn't working too hard.

[Bucket Head]

I'm sure a compressor unit is not cheap, but I can not speak on the cost of those. My $500 tank included the compressor. However, I did not know at the time of purchase if it worked or not. But with that said, after seeing how much this tank has helped me, I'd get another compressor unit coming tomorrow for it if it failed.

Steve

[sapman]

Do refrigerated tanks do fine outdoors in the weather? I realize they are usually in a milk house. But would there be a problem using them without any shelter?

[TapTapTap]

I assume there aren't any type of tank jackets that provide sufficient cooling capacity. It would make cooling concentrate a lot more practical since you could still use the head tank, with the jacket, which would eliminate the bulk tank and required room. There would seem to be value in a jacket since all the tank capacities and dimensions could be optimized to an individual's situation. I have learned the building around an odd shaped tank which you buy at a great price is not the way to save costs.

[BAP]

The compressor itself needs shelter from the rain and snow but also needs good airflow around it. The tank itself can be outside but it will freeze inside if you get prolonged really cold weather. Other than the agitator motor, there is nothing on them that needs weather protection.

[Bucket Head]

Ken- I have seen water-holding tanks that had the exterior covered with dense, black foam insulation. I'm sure you could insulate a tank somehow with all the different types of insulation out there.

Tim- Bap is right. They can be outside but unit needs to be out of the weather. My working bulk tank is inside the sugar house and all my raw sap storage-only bulk tanks are outside without any cover. They all have their original lids and covers and I removed the agitator motors and fabricated small covers for those openings. And I put some sealant around where the agitator power cord goes into the tank, just to try and keep any moisture out if I could.

[TapTapTap]

Ken- I have seen water-holding tanks that had the exterior covered with dense, black foam insulation. I'm sure you could insulate a tank somehow with all the different types of insulation out there.

I agree that there are many obvious ways to insulate a tank which could help . But insulation alone is not a solution since it might only insulate warmed sap from the RO process from cooling.

What I'm talking about a jacket with a coil attached to a refrigeration system. Then you'll need some type of insulating jacket over the cooling coils.

[Bucket Head]

Alright, I understand what you meant now. The cooling coil would have to be in contact with the tank skin itself. A bulk tank's "cooler" is attached to the bottom third or so of the tank. It cools by conduction/contact. The other way would be to submerge the cooling coil in the sap. There is a chiller tank at work that cools the water that way. And then there are plate coolers too but I have no experience with those.

[Shaun]

I just picked up a Sunset 625 gallon 100% complete working unit for $1500. I have seen them for less but this will fit and replace my current head tank, an 800 gallon open top tank. I will also have a few hundred more getting it installed. I think this will really help my operation, quick math says it will hold ~100 gallons of syrup at 15% concentrated sap. Even a few less startup and shutdowns a season will really help efficiency.

I only plan on holding concentrate a few days at most if needed due to work. How long are people able to hold concentrate at 8-15% at 30-34F?

[Bucket Head]

That's a great deal! Nice find. You will wonder how you got by without one next season. They are an extremely useful sugaring tool.
The first year mine was up and running, I held 12% concentrate for six days, as an experiment. That concentrate made great looking and great tasting amber syrup. I figured the syrup would be okay but seeing was believing. Good luck with the tank!

Steve

[minehart gap]

How long are people able to hold concentrate at 8-15% at 30-34F?

Dr. Tim attached a chart on the first page of this thread that shows recommend temperature to hold sap at various concentrate levels. Looking at that chart, I don't believe you would want to store that sugar content sap for very long at that high of a temperature. You should be less than 30 degrees for 8%.

[DrTimPerkins]

How long are people able to hold concentrate at 8-15% at 30-34F?

Unfortunately that is not a simple calculation. Deterioration in storage is a function of sugar content, time and temperature (and starting level of contamination of the sap/concentrate and equipment).

- Higher sugar content means faster deterioration.
- Longer time period means more deterioration.
- Higher temperatures lead to faster deterioration.

In general, you can think of sap (or concentrate) as milk or some other perishable that you keep in the fridge(which is typically about 40 deg F). It'll almost certainly last several days (assuming it wasn't highly contaminated to begin with), but once you get beyond a week or so, you're taking your chances. If it is colder, it'll take longer to spoil.

21471

This chart is a good general depiction of the growth rates of different classes of microbes at various temperatures (note that the scale is in deg C, not deg F). Very few things can survive well at really low temperatures. Those that can handle it can't grow very quickly. The red arrow is the temperature at which we keep our bulk tank. Not much happening at those temperatures.

There is a segment of a presentation I did a few years back on sap/concentrate spoilage as affected by time and temperature at https://www.youtube.com/watch?v=NnanxblnBJ4&list=PLZP4fDl-nB9806BqBzubk9c86w-H_5IBv&index=9&t=0s That particular portion starts at about 38 min in the video.

We've kept 35 Brix concentrate at 24 deg F for a couple of weeks with no deterioration in quality. Not a lot of microbes will grow at that temperatures.

[Howard]

Last year I priced out a used 2000 gal. refrig tank $18000+. I called a company that makes a coobot. Its a unit that is used for produce, beer soda to keep it cool. They gave me the instructions R values, size of room. And with help I built it to there specs. After running the 30% consentrate through a plate cooler it goes up stairs to a 2500 gal tank room . The coolbot unit keeps the tempature between 22 degrees. Total cost with labor $6000.

[Maple River Sugar]

I recently bought an open top 375 gallon refrigerated bulk tank for $180 I put $250 into repairs having the system checked and 5lbs. of refrigerant added. After reading this thread I think this will significantly change our operation allowing us to boil when we want versus when we must. My plan is to collect and process the sap through the RO to 8% then store in the refrigerated tank, then boil once a week or when the bulk tank becomes full. In other words RO'ing more often but boiling less. I'm looking forward to upcoming season.

[Bucket Head]

Keeping a room cold or a tank cold will achieve the same thing- less boiling stress! You guy's will be very happy with cold concentrate storage. Refrigeration is a great sugaring investment. -Steve

[DrTimPerkins]

Refrigeration is a great sugaring investment. -Steve

It's been an absolute game changer for us, especially when combined with HyperBrix concentration. We boiled 5 times total in 2019 (+ a boil-out) and 8 times in 2020, and made over 3,000 gal each season. Before we had the bulk tank we were boiling 18-25 times each year. We never boil less than 4-5 hrs at a time, but never on a weekend or at night. We always schedule the boil 2-3 days ahead of time. The biggest time savings is in clean-up.

[corrowbasin]

Another thing to consider is there are many submersible drop in chillers that can be used, which you can mount the condenser on-top of conventional tanks, while maybe not extremely efficient still work. I've been looking at such set-up on my 1500 gallon flat top bulk tank, since the refrigerant coils had leaks but picked up cheap. Check out LS Bilodeau website Bilocool

There's many others drop in chillers online used for marine aquariums that are over 6,000BTU/h that would probably work.

[Bucket Head]

A water chiller where I am employed has a cooling coil like that in it. My only concern with a coil like that would be cleaning it. It's pretty easy and quick running the bulk tank brush around the flat top bulk tanks without anything in the way. But with that said, a small amount of extra difficulty and some extra elbow grease during cleaning will be a worthwhile trade off for refrigerated sap!

[Shaun]

To follow up on this the refrigeration work was about $1000.00 which is a higher than I hoped but it is what it is. $2500 for a 625 gallon tank total.

[Kh7722]

It's been an absolute game changer for us, especially when combined with HyperBrix concentration. We boiled 5 times total in 2019 (+ a boil-out) and 8 times in 2020, and made over 3,000 gal each season. Before we had the bulk tank we were boiling 18-25 times each year. We never boil less than 4-5 hrs at a time, but never on a weekend or at night. We always schedule the boil 2-3 days ahead of time. The biggest time savings is in clean-up.

Dr Tim
Are those units financially feasible for the average sugarmaker or mainly for the big guys? Reason im asking is it would be great to concentrate all week and boil on weekends only. Not sure if I have power source to run a big cooler either
Kevin

[mainebackswoodssyrup]

Thanks for posting the update. We did not pull the trigger. I can pretty much take time off whenever I need to so our sap doesn’t sit around. But I still plan to have one some day. The convenience would be nice.

[Bucket Head]

I wouldn't say that refrigeration is just for the "big guys". I wouldn't call myself a big guy at 400 taps. Everyone has to determine for themselves what is financially feasible for their operation- or what they could swing for some convenience and a little less stress. The refrigeration allows me to RO all week and then boil on the weekends when I have the time. I gather and RO weeknights after work. There is no way I could gather, RO and boil during the week. That nuisance we call a day-job makes syrup making a challenge for some of us. My bulk tank has reduced my in-season maple stress level immensely!
What do you have for an electrical feed?

[Kh7722]

I wouldn't say that refrigeration is just for the "big guys". I wouldn't call myself a big guy at 400 taps. Everyone has to determine for themselves what is financially feasible for their operation- or what they could swing for some convenience and a little less stress. The refrigeration allows me to RO all week and then boil on the weekends when I have the time. I gather and RO weeknights after work. There is no way I could gather, RO and boil during the week. That nuisance we call a day-job makes syrup making a challenge for some of us. My bulk tank has reduced my in-season maple stress level immensely

What do you have for an electrical feed?

Basically 100 amp service at the sugarhouse

[afretired]

A lot of milk tanks have been scrapped around here, and they are getting harder to find, but there are still several out there. I have two for my maple syrup production, both 600 gal, one just for a holding tank out side without a compressor unit. Then I have one inside, up in my loft with a compressor unit. when I gather my sap from the woods, I haul it back to my sugar shack and pump it into the tank in the back. I then use a sump pump to pump it up to the tank in the loft and chill it if necessary. I then gravity feed out of this one to my evaporator.

This second tank with the chiller, was a real game changer. Our weather swings so violently I can now gather for a few days and chill it with out worrying and have enough for a good boil. Before I would have to boil a few hundred gallons, and shut down.

[Bucket Head]

How much electricity are you using? What are you running at the sugarhouse with the 100 amps? How many amps are "left" with everything else running? My tank is not hard-wired in- it's on a hay wagon gear so it's movable if need be- so I had my electrician put a 30ft. cord on it and it has a 220V, 20amp, three prong plug on it. So, it's not drawing a lot of electricity. Well, not a lot compared to other 220V devices like dryers, ovens and welders.

Steve

[DrTimPerkins]

Dr Tim
Are those units financially feasible for the average sugarmaker or mainly for the big guys? Reason im asking is it would be great to concentrate all week and boil on weekends only. Not sure if I have power source to run a big cooler either
Kevin

Not just for the big guys, but all depends on the time you have available and what your time is worth? Are you making syrup to make money, or is it just a hobby? The size of the tank depends upon how high you're concentrating, how many taps, and how long you want to go between boils.

[Shaun]

The compressor for the 625 gallon tank is 3HP, about 17amps plus a couple for the agitator motor. For me when the temps are above freezing for a few days in a row I can spend time in the woods, fix leaks and boil every other or third day when the vacuum is bringing in .75 to 1 GPT a day. I am sure there will be times early season when I will not turn it on but can if needed or a short run. I will know more in a few months if it was the right choice for a small producer.

[mainebackswoodssyrup]

I don’t think you’ll have any regrets even if you don’t use it every week. It’s going to save you a lot of time over the course of the season.

[Bucket Head]

I agree with Maine. I can not envision any serious sugarmaker saying they regret investing in refrigeration after using one of these tanks- regardless of their size. My biggest regret? Not getting mine operational sooner than I did. And I won't be without one going forward.

Steve

[mapleack]

Not just for the big guys, but all depends on the time you have available and what your time is worth? Are you making syrup to make money, or is it just a hobby? The size of the tank depends upon how high you're concentrating, how many taps, and how long you want to go between boils. Dr. Tim, what do you do between boils with the sweet in the evaporator? Filter it and add it to the bulk tank once cool to preserve until the next boil? I just got a 600 gal delaval that worked but the compressor was shot. Will have it up and running for next season for time / life management.
Thanks,
Andy

[DrTimPerkins]

Typically at the end of a boil we drain the front and back pans into separate insulated draw-off tanks and put the lids on. This allows us to clean the pans. The liquid is hot enough that it kills any residual microbes. We don't open them again until we pump the sweet back into the pans. We usually boil about once a week, so the sweet is fine that long with this procedure. If it was going to be really warm for a few weeks, we'd probably pump the sweet back into the pans and fire up for 5 min (easy to do with an oil-fired evaporator) -- just long enough to boil the liquid a bit. It it were really hot, we might consider putting it into the bulk tank.

[mapleack]

Typically at the end of a boil we drain the front and back pans into separate insulated draw-off tanks and put the lids on. This allows us to clean the pans. The liquid is hot enough that it kills any residual microbes. We don't open them again until we pump the sweet back into the pans. We usually boil about once a week, so the sweet is fine that long with this procedure. If it was going to be really warm for a few weeks, we'd probably pump the sweet back into the pans and fire up for 5 min (easy to do with an oil-fired evaporator) -- just long enough to boil the liquid a bit. It it were really hot, we might consider putting it into the bulk tank. Thanks for the reply, I appreciate it!