How long can I store sap?

[S.S.S]

Last night we ran sap through the R.O. down to 21 Brix. It was 19 degrees in the storage tank it sat for 12 hrs before cooking. Now We are having problems with filtering. We can only get 5 gallons through our 7" press before we have to change papers. Could this be because we let sap sit to long with a high sugar content?

[Russell Lampron]

Yes more than likely. Bacteria grows fast in concentrated sap and that bacteria quickly clogs up filters and filter presses. I heat my syrup to boiling or just under and it goes through the filter press much easier.

[adk1]

I do not have an ro but have learned that an ro concentrates everything including any bacteria that was in your raw sap. With that said u will end up with concentrated sugar and bacteria in a lesser amount of liquid.

[psparr]

Just a thought. Does anyone run concentrate through a uv light?

[ice cutter]

I think you are correct. Concentrate does not store. We always boil within an hour of concentrating., but late season syrup is always harder for us to filter.

[ice cutter]

Tried it a few years ago and it did not seem to help at all.I think the sap is already damaged by the bacteria before we put it threw the ro so the light did not do us any good.

[Clinkis]

Just a thought. Does anyone run concentrate through a uv light?

Tried it also and didn't seem to make any difference. I remember researching it at the time and believe because sap (especially concentrated) is not perfect clear and therefore the light can't pass through it to kill bacteria.

Aside from concentrating the bacteria, the RO also warms the sap which increases the issue. Later in the season or if it's warm out concentrate can start turning bad very quickly.

[mellondome]

S S S,
When you change the press, are the cavities full ? Or is the press stopping before you have completely filled the cavities with de?

[Diesel Pro]

I routinely process mine on Friday eve/night cutting it by 50% or so and pulling the plug at 10pm then pick up the next morning where I left off and run the RO pretty much continuously until my take off rate drops to .2 gpm or so. By that time we are already boiling. Working outdoors at the cabin can make things a bit tricky with the cold mornings or I would look to try an early am start on the RO.

Two seasons ago I made the mistake of running the RO mid week and storing concentrate. It still made good syrup, but I could see the bacteria growing on the tank walls. I still have yet to make any syrup that would be considered dark black. Mostly medium amber maybe medium dark, but never the black stuff like I often see in stores.

[Bucket Head]

At the start of the season I R.O.ed sap on Tues. and due to a house furnace failure and three days of bitter cold, I did not boil until Sat. That sap made some of the lightest syrup my father and I have made in a long time. Granted, it was early season sap versus late season sap, but I kept it in an insulated milk bulk tank (which actually kept it warmer than the outside temps. The sap stayed close to the temp. that it was when it went in) and the temp. never went above 35 degrees. We had teens and single digits for a few days here early in March.

Back in January at the V.V.S Maple Conference I attended a seminar about high sap concentration that was presented by a representative from H2O Innovations. Rock Gaulin was the presenters name. I wasn't interested in high concentration- I wanted to here about the R.O.'s inner workings and performance, care for the unit, etc.- but he said they have stored high brix sap in refrigerated bulk tanks for weeks. Up to one week showed no degrade in sap and over multiple weeks there was only a slight degrade of the sap. He did not say what temps. it was stored at, if it was early or late season sap or what grade syrup it made, but he was trying to prove that sap/concentrate can be stored.

I hope to "experiment" a little more with the bulk tank I just got operational. Hopefully we'll get a little more sap that I can R.O. and hold till the weekend. To be continued...

Steve

[Clinkis]

I usually remove about 80% of the water (15%). Last year near the end of the season I learned the hard way that my concentrate would spoil in less the 24 hours. unfortunately I have no way of keeping it cool late in the season.

[maple flats]

If the concentrate was even close to 19 or low twenties, that should be fine.
The year before I got my RO I had too much sap and I sold 1150 gal to a producer on Sunday and Monday (1150 total, not each day). He concentrated it to 8% and pumped it to a refrigerated tank he has and kept it at 30 degrees until Sat., which was an open house. He then made medium out of it and it filtered normally. Now, that was 8% and you had 21%, I don't know if those relationships would totally change that or not. I do know that concentrate spoils fast if not kept cold enough, but if you had 19 degrees it seems like that should have cooled it enough.
Try a little more FA, or is that why you need to change papers, when the hollow plates fill with FA? If that's the case, try slightly less FA.

[woodey24]

What about fresh sap? Will it make it a week if kept cold? Longer?

[DoubleBrookMaple]

What about fresh sap? Will it make it a week if kept cold? Longer?Definitely... I researched and read a week at 40 is fine. I did that my first couple years when I was on buckets and gravity tubing. I was piling snow around my containers to keep the sap cold during the warm weather. Some slight cloudiness, and syrup was fine. Longer? I think so. Watch the clarity of the sap is what I would say.

[S.S.S]

The press wasn't plugged tight but the syrup was just a little bit stringy. Tasted good and what was filtered looked great also.

[DaveB]

Just curious after reading some of the responses here. Can you inhibit bacterial growth if your storage tank is enclosed and you have a UV light over the tank? Would that limit the bacterial growth or harm the sap?

[Bucket Head]

Cold is key when holding sap. Forty degrees, preferably less, is whats needed- just like your refrigerator.

A UV light over a tank won't do anything to stop bacteria growth. An in-line light, like a home water supply unit is whats needed and even then they are very limited in slowing the growth. Treating sap with UV is not nearly effective as treating water. The sugar molecules prevent the light from penetrating and "contacting" all the microbes. The UV lights will help to a degree but are not the complete answer to storing sap.

UV treatment and cold storage would be a great combination though.