Concentrate Storage Time Limits

[Conococheague]

My partner and I have a hobby operation with about 40 taps on all sugar maples. He is a dairy veterinarian and I am a mechanical engineer working 60 miles from home. My long commute and his unpredictable schedule (he does a lot of embryo transfer on farms upstate and out of state) make it tough to schedule long boil days. We run two boilers and two RO’s and usually have some extra help from curious friends. Here’s my question - if we RO sap from 2% to 4%, how long can we store the concentrate (refrigerated) before we boil it? Could it be RO’ed on a Friday and boiled the following Sunday (stored for 2 days)? I thought I read on here somewhere where this isn’t a good idea but I can’t seem to find that thread.

Thanks

Conococheague

[Brian]

Yes as long as it is refrigerated. I ro to 7 and let it sit for 24 hrs as long as it is around 40 deg f. and had no problems.

[DRoseum]

The colder and shorter the time the better.

[Mean_Oscar]

How about if you freeze the concentrate?

2004: 1st Maple Syrup Festival at Tipton Haynes-Historic Site
2022: Ropey syrup from black birches - built RO 2 x 75 and 2 x 100
2023: Discovered freeze-thaw concentration - got 5 cf freezer
2024: 21st MS Fest with 18” x 27” and 48” stainless pans
Interests: alternative trees, freeze-thaw, vacuum boiling

[TheNamelessPoet]

Colder as short a time as possible. I couldn't boil for almost 5 days, but it was near freezing (under 35, mostly under 32.) I RO'd to about 4-5% so it would fit in my 35 gallon tank that was outside. The day before I started ROing the night before up to about 8-10%. It came out BEAUTIFUL.

You are most likely NOT making the super fancy, water looking stuff that SUPPOSEDLY is premium, but I can tell you mine looked AMAZING and the taste was great. If possible store it in the freezer, it wont freeze, it turns to a slushy line state, especially when you get over 5%. To me this is perfect. It can be a PITA to get it out of the bucket if it froze any more than that anyway. I only "freeze" it if I can get it to 8-10% and wont be boiling it for 2+ days. Ill be honest tho, I just boiled some that I had in my fridge since LAST YEAR, that was at about 60%. No mold, tasted great, but as VERY dark. Not quite molasses dark, but even in 500 ML glass bottles it was WAY darker than I had ever made. OMG tasted AMAZING though. I thought so and so did my customer. I am actually kind of tempted to do it again this year with 1 gallon, since he loved it so much. He wants all of that before I make/sell any this season.

[fireant911]

...just another experience here...
I think each time I processed that there was at least two full days between running the sap through the RO and then boiling it. It may be noteworthy to state that I did not heat the sap so it was all processed at less than 40 degrees F. Also, my RO has a UV lamp which may or may not help with spoilage. After processing through the RO, I stored the concentrated sap in a snow bank. Because of my limited supplies of buckets for gathering sap from the bags, there is always a balancing act of gathering, running through the RO, and finally boiling. Probably the longest was six days from gathering and five days after running through the RO. We never had any issue BUT as others have stated, minimizing the time from gathering to boiling is the best!