When is it done ?

[SUGARSMITH]

I finally boiled this weekend and made a meager 5 gallons of what I think is syrup. The color and flavor is great but the specific gravity apperas to be off, too thin.

Here is what I do . I use a markland drawoff and set it 7.1 degrees above the boiling point of water for the given atmospheric pressure. I even bought the marcland digital barometer/boiling point converter.

This past Saturday the boiling point was 209.7 so I set the drawoff at 216.8. Should of been an exact.


The hydrometer at days end showed me 58%, if I remember correctly.

My question is where would be the most likely cause for error. Would it be the auto-draw ? Do these need to be calibrated every few years ? Digital barometer ? Which is only 2 weeks old, or is my hydrometer out of wack.

I can cross check the barometer and drawoff which I will do, and that will leave the hydrometer. When these ship from the factory are the always 100% accurate or do they as well need calibration.

Any thoughts greatly appreciated



Dan

[sweetwoodmaple]

http://ohioline.osu.edu/b856/b856_77.html

Easiest way to double check is boil some of the syrup and measure the temp with another device like a kitchen thermometer. As the above data points out, you should see a 2 degree drop if things are truly at 58%. Of course, make sure you boil water and measure the temp first with whatever device you use to double check.

Sounds like maybe the hydrometer paper has slipped in the tube.

Do you have access to a refractometer? Another way to double check.

Electronic equipment is great and all, but since my profession is in materials test equipment, the bottom line is that everything needs calibration or recertification to the "standard" at some point. And...the more devices you have in the loop (auto draw off, controller, barometric pressure compensator), the greater the risk for errors.

Hope this helps... :?

[brookledge]

Do you have the conversion chart from Marcland telling you the boiling temps based on the barometric pressure. 209.7 degrees equals about 28.5"Hg which seems real low unless you were in the middle of a low pressure. I know from watching my barometer that on some days it will change quite abit from start to finish. I'm always watching the barometer and ajusting my draw off temp. When I test it to my hrdrometer it is right on. Look at the local forecast and see what they have for a barometer reading and compare to yours. It could be that yours needs to be calibrated to your elevation which can throw it off. All I can say is double check each instrument until you find which one is off.
keith

[sapman]

When I got my Marcland draw-off, it was recommended to me to just start drawing off a little at a time when it's getting close, and check with the hydrometer. Keep doing this and adjusting the draw-off accordingly til you find the "sweet spot" when it's done. This seems like the most practical and fail-safe method for me, and reduces the guesswork. Once it's set, I still usually check each draw, or every other, as the barom. pres. will change throughout the day. I've had days where the draw-off temp. went down over 2 degrees over about 6 hours time.

Tim

[Johnny Cuervo]

When I bought my hydrometer 3 years ago they told me to mark a reference line in its box, this way you check it every year to see if the paper moved.

John

[brookledge]

Thats a good idea. Just don't lose the box.

[WF MASON]

Reading the posts in this forum I took the time to stop and look at Johnny Cuervos pics he has listed.I never take the time to look at thoes.
I've seen many many homemade evaporators , that has to be one of the coolest, I assume Johnny you've named it ? The name that comes to mind for me would be Thomas - as in Thomas the train . I see alot of people who had a good time sugaring with a rig that size, but felt they had to move up in size and add more taps and more work and it was'nt as much fun. Nice job , enjoy.

[sweetwoodmaple]

Great point by sapman, there is always a hysteresis associated with these devices.

Therefore, you really have to make the draw off open slightly dense so that when it finally closes after the temp drops, the mix in the draw off pan come out right.

Similar to when you are running with a standard thermometer and ball valve when you draw in batches in a small evaporator like mine. You never want to wait until the thermometer actually drops before closing the valve, because then it is too late and you already have light syrup in the draw off pan.

Brian

[saphead]

Sugarsmith,Keith was right on with his calculation.During the storm 28.5 "was what I read on my barometer.

[WESTVIRGINIAMAPLER]

You may have been right on at the start of boiling but 2 or 3 hours later, it was off. In my opinion, the only way to get exactly the finished product unless you want to keep changing things every hour or two is filter and finish in a controlled enviroment such as gas or oil heat and test with a hydrometer. :?

[SUGARSMITH]

I am going to get a new hydrometer today and make sure that it is calibrated.

I had the same pressure that day of 28.84, if I remember correctly. Converted it to a boil temp of 209.7 added the 7.1 etc.

I will check it all tonight. Just want to be sure I am selling syrup, not concentrated sap

[ontario guy]

When doing your calculations you might have to take into account your elevation... i don't cause i am only 100m above sea level. But if you are at a higher elevation you need to take this into account for your boiling point... There is information on the web and charts i believe. It has been a couple of years since i looked it up.

Mark

[brookledge]

Sugarsmith,
if you had 28.84 that would be boiling point of water of 210.2 then add 7.1 (I always add 7.0) you would get 217.3 and you said you had it set on 216.8 so that is .5 degrees on the light side. Hope things are going well for you.
Keith

[gmcooper]

Does anyone know where to get a chart with barometric pressure and boiling points? I had one years ago and haven't seen it in years. I tried online but only found a site that would do the calculation for you but no other info.
Thanks
Mark

[brookledge]

When I bought my auto draw offf from marcland I got a chart with it. I did a search of marcland and found under the barometer literarture section the conversion chart is there in inches of mercury and in millibars.
Keith

[gmcooper]

Thanks Keith. That was the one place I never thought to check. should have put 2 and 2 together and got at least 3!
I'l check it out
Mark

[murferd]

Boiled the first time tonight,installed our new Ystec auto drawoff.It shows barometric pressure,boiling point & adjusts our drawoff temp automaticly if baro pressure changes.Wasn't sure how it worked but found out quite quickly.When I first plugged it in,pushed the button & baro pressure was 29.something,boiling point of 211.0 so we set our drawoff at 216.A couple of hours later we noticed the drawoff temp was now at 216.1,pushed the button & the boiling point was at 211.1 real neat ! We finish our syrup at 7 degrees above boiling in a finishing pan after we get about 10 imp gals.We also set our close drawoff temp higher than our open that way the temp drop isn't as severe,the syrup temp is always hotter after the valve is open for a few seconds,this way it closes without dropping too far.

Murferd

[saphead]

Never heard of a Ystec auto-draw, how much $ and what comes with it:type of valve,etc?

[Russ]

http://www.ystec.com/

[ontario guy]

http://www.csgnetwork.com/h2oboilcalc.html

here is a calculator with elevation.