Concentrate lifespan

[DaveB]

I do not have an RO but I've seen it mentioned several times that the concentrate spoils quickly which is why you either want to boil it right away or have it run in real-time with the evaporator. Can someone tell me how quickly it spoils or how long the concentrate can last? Also, by spoiling, do you mean that it would create a darker grade or be no good?

[maple flats]

That depends on the concentrate temperature. If over 40 you start losing grade and sugar rather quickly. Try for 4 hrs. max. However 3 yrs ago, the year before I got my RO, I had to sell sap for 4 days, while I boiled what I had. The guy I sold it to was getting ready for Maple Weekend and the forecast looked too warm for good flow, so he concentrated what I took him on Tuesday, added it to his own concentrate (both were at 8%) and pumped it to a refrigerated tank. He cooled it to 30 degrees and boiled on Sat and Sunday. He made some nice Medium Amber, on the lighter side, almost a light amber. Thus, if you can get it cold it will keep 4-5 days. At 30 degrees it will not freeze because of the sugar, but there is very little micro-organism growth.

[jmayerl]

I would not ever keep concentrate for more than 4 hours.

[DaveB]

That depends on the concentrate temperature. If over 40 you start losing grade and sugar rather quickly. Try for 4 hrs. max. However 3 yrs ago, the year before I got my RO, I had to sell sap for 4 days, while I boiled what I had. The guy I sold it to was getting ready for Maple Weekend and the forecast looked too warm for good flow, so he concentrated what I took him on Tuesday, added it to his own concentrate (both were at 8%) and pumped it to a refrigerated tank. He cooled it to 30 degrees and boiled on Sat and Sunday. He made some nice Medium Amber, on the lighter side, almost a light amber. Thus, if you can get it cold it will keep 4-5 days. At 30 degrees it will not freeze because of the sugar, but there is very little micro-organism growth.


I would not ever keep concentrate for more than 4 hours.

Both you guys mentioned that 4 hour number...any specific reason? What would happen if you batch processed over night and waited 8-12 hours to boil?

[DrTimPerkins]

What would happen if you batch processed over night and waited 8-12 hours to boil?

You would end up with LOTS of very happy microbes....possibly resulting in fermented sap or ropey syrup. In general, you want to treat sap as though it were milk (in terms of spoilage), which means filter it well, keep it cold, and process it quickly. With concentrate, since there is so much more sugar, it will spoil that much faster.

[DaveB]

You would end up with LOTS of very happy microbes....possibly resulting in fermented sap or ropey syrup. In general, you want to treat sap as though it were milk (in terms of spoilage), which means filter it well, keep it cold, and process it quickly. With concentrate, since there is so much more sugar, it will spoil that much faster.

OK, that makes sense. I've had sap start to ferment and become ropey - not a happy sight. I tried boiling it once but I thought I was going to lose my lunch with the smell. It was after a couple of days when temps hit the 70s and I just couldn't get to it.

I know that you're supposed to treat sap like milk which is why you need to keep it cold but I didn't think that the extra sugar would act that quickly.

[wiam]

I try not to but probably once per season for some reason I am not able to boil on a night. When it happened last year I had been making medium. The next morning I started making dark and I had not made any yet. I thought cool, got customers looking for that. Went right back to medium. :/ Moral, I try not to let concentrate sit but early season you might lose a grade overnight.

[Bucket Head]

Similar to William's situation, I once RO'ed sap and then could'nt boil it until the next day- 16 hours to be exact. I pretty much watched each hour pass on the clock thinking it would be wasted sap. I boiled it and it turned into Grade A dark syrup. Not ruined, tasted great and was perfectly sellable. As mentioned, keeping it cold is the key. It was still March so it was cool outside and I put some "ice cubes" in it. Ice cubes being the blue, 5 gal. bulk syrup jugs filled two thirds with water and frozen. I put them in a chest freezer. Yes they swell a little bit but I've never had one break.

Steve

[Diesel Pro]

Last season was my first season and we tried keeping concentrate. It wasn't a disaster by any means, but we learned that we don't want to do it for days. We tried a Wednesday concentration, Saturday cook and started to get growth in the tanks.

This year we'll keep the sap "loose" until Friday evening. I'll land at the cabin and start the RO until it's time to turn in then resume in the morning and start building the fire in the evaporator.

[Clinkis]

Both you guys mentioned that 4 hour number...any specific reason? What would happen if you batch processed over night and waited 8-12 hours to boil?

This is what I do and have no problem as long, as others have mentioned, you keep your concentrate cold and you practice good sanitation practices. I run my days collection through the RO overnight and boil the next evening. I thoroughly rinse my RO each day and change my pre filter very frequently (everyother day usually). I discovered that my pre filter is my biggest area of microbio growth. By following this practice I make light to medium syrup for most of the season. It becomes more of a challenge later in the season as temps rise.

[tcross]

what about boiling down sap and leaving it in the pan for whenever you get more in? pretty much like concentrate, correct... or denser? I boiled down 75 gallons last weekend and left it in the pan covered until... well, I'm not sure when the sap will run again? Have I ruined what I boiled down? it hasn't been above 28 degrees f in my sugar house since then!

[Run Forest Run!]

Sap that you've concentrated through boiling is different than sap that's been put through an RO. You are totally fine since it's been boiled and then kept nice and cold. Now you can exhale. ;)

[tcross]

lol... Thanks for the vow of confidence rfr! I could have had nightmares tonight... lol! :)