High Brix RO

[PCFarms]

This year we bought a high brix RO, I thought I would share some of our experiences, and I have a question if anyone else out there can help.

We made 35 brix concentrate this year, the RO worked really well. We were able to consistently get 30 plus on the brix readings, I would say the average was around 33. Boiling was a little more difficult until we got used to it - we needed to keep the level in the pans higher so that we were able to get good flow through the evaporator, this also made boil-overs a little more common. At that high brix the ratio is about 2.5:1, so the syrup comes off quickly. We never had a long boil day, our best day we boiled for about 8 hours, it essentially saved us an employee, we operated with 1 fewer people this year and we managed easily. Further, with the price of diesel double what it was last year, we saved a huge amount on energy costs as well. In all, taking the credit for the old RO, the upgrade to a high brix machine has a 2 year payback. This is phenomenal, and I encourage others to think about this transition.

We do not refrigerate the concentrate, so we were always careful to boil it within an hour or two of making it. This resulted in a lot of small boils, where we had many 2-3 hour boils in a day (adding in set up and clean up as extra, there is a lot of extra time required on the ends). It would be great to refrigerate the concentrate (as Dr. Tim does) and combine a bunch of boil days into one big day, saving us a lot more time. My question is, if we are able to chill the concentrate to about freezing temperature, how long can concentrate be stored? days, weeks? what about could one go so far as to propose that some concentrate is stored until the season is over and then process it all in May?

[motowbrowne]

I'm just an observer of the high brix conversation, but I've seen people, including Glen Goodrich say that they can store refrigerated concentrate for days, or up to weeks. I certainly see the appeal of that and over got my eye out for a bulk tank myself.

As far as concentrating all season and processing at the end, that seems a little goofy, in part because you'd need a LOT of cold storage. I mean, 38k taps makes what 15-20k gallons of syrup. You said 2.5:1, so you'd need 40,000 gallons of refrigerated storage. It is easy to see the payback of the bigger RO, not sure what the payback period of ten 4,000 gallon bulk tanks would look like. Maybe an enormous cooler with regular sap tanks inside instead?

[fred]

Many have gone several weeks of concentrated sap, stored at 25 degrees. I would not recommend saving till the end but a large tank to store for a days run and boil every other or every couple times is still very helpful.

[DrTimPerkins]

We concentrate to 32-35 Brix (typically the higher end), store in a bulk tank at about 25 deg F, and boil 1-2 times weekly depending on the season. Works great for us as we then have time to do all the research that comes with our work. Has led to far fewer compromises on either the research or production side of the work.

High RO concentration does save a lot of time and energy itself, but a great deal of the time (and labor) savings is in the setup and cleanup side. Each boil adds an hour to the setup and two+ hours to the cleanup, so cutting back on boils saves some serious labor time.

All those advantages are great, but the big disadvantage is that if the concentrate does go bad, you lose an awful lot of production very quickly. We had to dump over 700 gal of 35 Brix concentrate last year because it went ropey in the bulk tank. Most likely it would have gone bad anyhow (it was questionable going into the RO and even more so coming out), but still was very painful seeing all that literally going down the drain. For that reason, if it has been warmer than usual, we'll boil more frequently (twice a week). If it was good and cold during the run and it went into the bulk tank quickly, we'll let it go longer (up to a week). I wouldn't try to let it collect for a whole season even if we had the storage...too many eggs in one basket kind of thing.

That said, we did get a second refrigerated bulk tank last year, so we doubled our cold storage to over 1,400 gal (1 600 gal refrigerated bulk tank, 1 500 gal refrigerated bulk tank, and 1 300 gal non-refrigerated but insulated tank) just to have a little extra leeway. Longest boil has been about 8 hrs, but typically they're about 3-4 hrs.

[ennismaple]

Thanks for sharing your experiences. Is refrigerated storage any less or more effective on 18-20 Brix concentrate?

[DrTimPerkins]

Not greatly. Freezing point would be a bit warmer, around 27-28 deg F (note that the freeze point is best determined for each individual bulk tank and concentration level as things will vary a bit...you want it as cold as possible but NOT frozen). Obviously, a lower concentration level would require more storage as well.

[Andy VT]

This is an eye-opening thread to a small producer like me with 9 taps! Sorry to hijack a thread into a slightly different direction, but 2.5 to 1 is a mind-boggling ratio, and it makes me wonder... does it even make sense to use a continuous flow evaporator at that point? That's about the ratio I have when I bring the sap inside to finish on the kitchen stove. Almost seems like one really big finishing pot would do ya! I suppose it is still too much volume for that, but it sure makes one rethink the process!

[ennismaple]

This is an eye-opening thread to a small producer like me with 9 taps! Sorry to hijack a thread into a slightly different direction, but 2.5 to 1 is a mind-boggling ratio, and it makes me wonder... does it even make sense to use a continuous flow evaporator at that point? That's about the ratio I have when I bring the sap inside to finish on the kitchen stove. Almost seems like one really big finishing pot would do ya! I suppose it is still too much volume for that, but it sure makes one rethink the process!

That's the perfect way to run continuous flow - once the runoff valve opens it never closes until you turn off the heat! The evaporator doesn't hold enough volume to process that much concentrate in batches. The density would be so sensitive to how long it's boiled that the difference between 62 Brix and 70 Brix syrup is likely 60 seconds.

[Andy VT]

That's the perfect way to run continuous flow - once the runoff valve opens it never closes until you turn off the heat! The evaporator doesn't hold enough volume to process that much concentrate in batches. The density would be so sensitive to how long it's boiled that the difference between 62 Brix and 70 Brix syrup is likely 60 seconds.

That's pretty much what I experience on the kitchen stove when finishing! Thought it was just me but I guess batch finishing to the right density really is pretty tricky! But I have now digressed pretty badly from the topic, sorry about that!

[jrgagne99]

...you want it as cold as possible but NOT frozen....

I assume this statement is made from a logistics perspective (i.e. it could damage your refrigeration tank). Or is there some adverse effect on syrup quality from sap that has been previously frozen?