Moving to Continuous Flow

[HondoLane]

I’m moving to a continuous flow pan this year and I have a few questions about finishing / filtering / and bottling.

Last year I’d bring it close to syrup on evaporator, filter into stock pot, and then start to finish on propane. When I’d hit the right density, I’d run it through the filter again which was tougher due to its density. Then I’d put it back into a pot and bring up to 180 degrees and bottle.

Now how would this be different with a continuous flow pan when I draft off small amounts? If I only draw off like a pint or so per boil, what do I do with it until I have enough to filter or bottle?

Last year I only tapped 8 trees and had to wait until I had about 30 gallons to boil. Gunna tap 25-30 trees this year.

[ecolbeck]

Over the course of a boil I will draw off syrup as it’s made through a filter into a large stock pot. I repeat this over the course of several boils until I have enough to can. I try to make my syrup a little heavy so that there’s no finishing to do.

[HondoLane]

Ok. I’m tracking now. Do you just let syrup that you drew off cool and cover until next time? Then add fresh syrup to pot until your ready to can?

Do you filter a second time after adjusting density?

[SeanD]

Typically, it's filtered as it comes off the rig. It's already hot and you have gravity working for you - although you have such a small amount that you could also just decant it later. If you use a combination of pre-filters and an orlon/wool filter and bring it right up to syrup, all your filtering is done in one shot. If you cover the syrup when you are done, it will be fine until your next boil. Then yes, add the new syrup to the original batch until you are ready to bottle.

Only pulling off a pint of syrup per boil means a larger percentage will be left behind in the filter. If that's the case, some people put their orlon/wool filter into a freezer between boils so as not to lose so much over the course of the season. Rinse out the prefilters though. There's nothing to save there.

[maple flats]

With 25-30 taps try boiling every other day, then you will pull off considerably more each boil, when the sap is flowing well you should get about 50 gal in 2 days. Once you establish your gradient ( the channels will vary from just above sap density to almost syrup density) then if you boil 50 gal of 2% you should draw off over 1 gal of syrup per boil (50/44) or 1.14 gal. of finished syrup.

[HondoLane]

Thanks.. that clears things up a little more.. I'm going to give the continuous flow a shot. Thanks for the help!

[HondoLane]

Here's another one I thought of... Going with a 2x3 continuous flow pan.

Should I go with:
1. warming pan and a sight glass on main pan
2. warming pan, float box, and sight glass on float box
3. float box plumbed to head tank and a sight glass
4. warming pan only
5. float box only

So many choices!!!!

[wnybassman]

I draw off a little heavy into large stock pots, and through a few prefilters. I wait until I have 6 to 10 gallons to finish/adjust density on propane. Takes very little time if bringing back to syrup if drawing off heavy. Once adjusted I run it through the final filters of the steam filter/bottler and bottle. Keep the stock pots of drawn off syrup in a cool/cold place and it can sit for days before needing to be finished.

[ecolbeck]

Here's another one I thought of... Going with a 2x3 continuous flow pan.

Should I go with:
1. warming pan and a sight glass on main pan
2. warming pan, float box, and sight glass on float box
3. float box plumbed to head tank and a sight glass
4. warming pan only
5. float box only

So many choices!!!!

I would definitely go with a float box. Continuous flow systems work better if the sap level is kept consistent. Sight glasses sound like a good idea. Warming pans are nice but their actual efficacy is debatable.

[buckeye gold]

I agree, get the float box and forget any warming pans. Plumb directly from a head tank to the float box and let it rip

[HondoLane]

Ok. I’m all in on the float box. Next question is.... build or buy a float box??

[maple flats]

Buy or build, your choice. However a float box works far better if it has 2 chambers (put a divider in with a small hole down low to equalize the chambers and have the float in the one that is separated from the incoming sap flow. That way the float gives a steadier control of the level. For the hole, it could either be a 3/4" hole or one corner open to give up to about that much open area to keep both chambers close to equal. If you do it with just 1 chamber the float jumps more and is thus less accurate.

[HondoLane]

What is a good size for a float box? I ordered a 2x4 divided pan. I was thinking 12" x 5" x 5". I will have leftover mirror stainless from my arch build. Was planning on using a flask as a float like some others have done. I can put in a divider to isolate the float from the inlet. I plan on running my pan at 2" deep.

[maple flats]

2" deep to learn how it works is fine, but then gradually reduce the depth until you are boiling either 1.25 or 1" deep. The boil will be harder and the flow in the pan will be steadier. Then when you draw off, open the draw off valve only slightly for a longer draw and less surging in the pan.
I used to try to see how long I could sustain a draw. On a 2x3 I think the best was about 15-17 minutes. When I moved up to a 2x6 I got a few draws of almost but not quite an hour. I think 20-30 minutes was more common. The point is, try to match the draw to the boil as best you can.

[HondoLane]

Is there a shutoff valve between the float box and pan? I am putting a sight glass onto my float box and wanted to drain float box at night and in between boils.

[Sugarmaker]

Hondo,
May not have read all the posts.
But yes you can put a shut off between the pan and float box. No real rules here. Makes sense if your going to drain it. Just remember to open it each boil. Burning up a pan due to a closed valve is not a good thing! Also most float boxes are open on the top and viewing the sap level is pretty straight forward with out a sight glass.
Just my 2 cents.
Have fun with the new equipment!
Regards,
Chris

[HondoLane]

Ok. Season u see way. I have a few questions. I boiled about 45 gallons in my 2x4 divided pan running at 1” deep. I definitely have a distinct gradient formed.

My thermometer is the 0-7 style. I calibrated it to boiling water at the beginning of the season. I know with pressure and my altitude the boiling point of water changes. How come my gauge is noticeably below the 0 when it’s boiling. The. At times it shoots up halfway (214-215) mark the back down to 0. I never seem to get a steady temp.

After 45 gallons running this rig at 1” deep. How soon can I expect my first draw?

[maple flats]

Did you calibrate it at a hard boil or just as it started to have bubbles rising. You should actually set it each boil, not just at the start of the season, the barometer is quite fluid, it often changes even during the day. For that reason I recently got a "boil meter" that gives the exact reading whenever I push the button, likely too pricy for a smaller operation. I've been at this for over 20 years, but only the last 16 have been commercial and it took me until now to buy one.
The other option is to use the thermometer as you have it and adjust the density as you get ready to bottle. I did it that way for years. My last 3 years I sort of adapted a little, once I got an auto draw, I set it for what I thought was right for draw off temp. then I checked the density during a draw using my test cup and hydrometer. I then adjusted the draw setting up or down as indicated by the results. That should also work if your draws are big enough to fill a hydrometer test cup. Best to use a thermometer in that cup to get a temperature reading just before taking the hydrometer reading and refer to the temperature chart in the North American Maple Syrup Producer's Manual to see what the density shold be at that exact temperature.

[HondoLane]

I tested it with a hard boil but on the stove in the house and not during a test boil once my rig was setup. Do you think my fluctuations will have to do with how far down in the sweet the probe is? The Badgerland (Smokey Lake) pan that I am using is supposed to be run at 2" as per the paperwork with the pan. I am running it at 1" The probe's last 1/2" is only in the sweet.

[Woody77]

I have smokey lake stuff (badger land) run at 2" like it says . I tried shallow and it ran worse. The draws are more consistent and tend to be a bit bigger witch helps in the filtering as it stays hot longer and goes through the filter better. As for the thermometer mine was acting up too when shallow.

[tgormley358]

Then when you draw off, open the draw off valve only slightly for a longer draw and less surging in the pan. I used to try to see how long I could sustain a draw. On a 2x3 I think the best was about 15-17 minutes. When I moved up to a 2x6 I got a few draws of almost but not quite an hour. I think 20-30 minutes was more common. The point is, try to match the draw to the boil as best you can.

Dave that makes so much sense thanks. I’ve been drawing off with the valve wide open. So the surging upsets the boil in both pans. So if my rig boils 20gph then a draw of 2 gallons should take 1/10 of an hour or 6 minutes. I can’t wait to try that.

[Woody77]

I boil about 50 gph on my 2×6. My draws are about every 20 minutes I do a slow trickle for about ten minutes each time . This years goal is to draw a trickle non stop if possible. It just seams like it boils faster the longer the draw is.