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View Full Version : Variation in boiling temperture?



sap seeker
03-16-2009, 06:06 AM
Had enough sap to make a small batch yesterday. Remember reading something about checking boiling temp for that day, something I had never done before, always assumed 212. Such a small producer, I just use the wife's candy thermometer. Stuck it in a small pot of boling water and it read only 208. Can there be that much variation? Is there something wrong with her thermometer? When I got my syrup to 215 it didn't pass the spatula "aproning" test so I took it to 219 anyways, looks a little thick this morning, guess I should have believed.

How much typical variation in temps. do you guys generally see, especially you central Maine folks? Thank you.

Jerome
03-16-2009, 06:42 AM
212 is at sea level at some specified pressure that I cant remember now. so yes you can be as low as 208 or as high as 215 depending on where you live and the atmospheric pressure.

PerryW
03-16-2009, 07:06 AM
My dial thermometer usually varies only a degree or two.

I'm guessing that your thermometer read a little low.
Syrup should be 7 degrees above the boiling point of water.

BarrelBoiler
03-16-2009, 07:15 AM
the thermometer could be wrong also or if yours is like mine the paper gauge inside could have slipped. so i have to take where water boils and add 7 and i usually fudge alittle. last time i did syrup i waited until it wanted to boil over then shut it down (finishing off inside) since mine is for personal use i finish it to different things: taste and feel of cooled syrup, how quick it gets sticky on a BIG spoon,7degrees above boiling, big foamy boil. ive made some thin and some thick but so far (knock on wood) never had mold or crystals.

have fun boiling

Stickey
03-16-2009, 09:36 AM
I too struggle with the whole temperature thing, I even have two thermometers to use. My sap seems to maintain a boil around 215 so I should not have syrup until 222. have not been able to get above 220 without the hydrometer telling me it is syrup. I'm afraid that at 222 all I'll have is sludge.

Toblerone
03-16-2009, 10:18 AM
I used to keep a barometer in the kitchen just so I could see how air pressure affected the boiling point. It's fun to see, but I always checked the boiling point of water. Lowest I've seen here is about 209 and highest was about 213.

But, I got so tired of messing with thermometers that I don't bother with it anymore. Now I just eyeball the syrup coming off the scoop and draw it off when it gets close (last few drops come off slow and apron just begins to form). After I get enough drawn off, I finish it in the kitchen using a hydrometer. It's been so liberating to just get rid of the multiple thermometers I had. That hydrometer is one the best $30 I've spent on our operation.

sap seeker
03-16-2009, 11:01 AM
Man, I've learned so much from this site, its awesome. Last year when I went to far with a batch I thought it was wasted. This morning I just went outside, grab a little sap and started boiling it. Added the stuff I made yesterday to it and brought it all back up to 217-218. I agree, I think her thermometer is a couple degrees low. Looks and pours much better now.

forester1
03-16-2009, 12:37 PM
You should check the thermometer in the morning against the barometer. The boiling point changes with the air pressure. I got 3 barometers in the sugarhouse, but that's just because I like them.

Stickey
03-16-2009, 01:08 PM
[(last few drops come off slow and apron just begins to form). After I get enough drawn off, I finish it in the kitchen using a hydrometer. It's been so liberating to just get rid of the multiple thermometers I had. That hydrometer is one the best $30 I've spent on our operation.[/QUOTE]

What do you mean apron? Like a skin, or film ? Isn't the hydrometer supposed to be used at certain exact temps? Mine says 211 degrees with a red line and 60 cold test line. How critical is that 211? I am scooping it up at between 215-220 but as soon as removed from heat it drops below 200 very quickly.

sap seeker
03-16-2009, 01:45 PM
Aproning means it falls off your spatula in a continous sheet vs. in drops. I've been told there are old timers who get their syrup just right using this method, no thermometer or hydrometer. It's certainly pretty close if not an exact science.

Toblerone
03-16-2009, 02:54 PM
What do you mean apron? Like a skin, or film ? Isn't the hydrometer supposed to be used at certain exact temps? Mine says 211 degrees with a red line and 60 cold test line. How critical is that 211? I am scooping it up at between 215-220 but as soon as removed from heat it drops below 200 very quickly.

I mean it starts to come off more like a sheet instead of a drop. Now, a full sheet would be finished syrup, but I want it before that point since I am going to finish in the kitchen where it's nice and warm and well-lit. So I go for kind of a wide drop just before it starts sheeting. Then I filter it (using cone grease filters from restaurant supply) as I draw it off. This gets most of the sugar sand out before I finish it, filter again and bottle.

I don't think the hot test temperature is absolutely critical. I would think that within a few degrees of 211 would be fine. I usually fill the hydrometer cup once and dump it so that all that thermal mass in the cup is brought up to temperature. You could also submerge the outside of the cup in the boiling syrup before filling. Then I refill the cup with the boiling syrup and put in the hydrometer. Two points about the temperature:

1) Look at the distance between your hot-test and cold-test lines. That's the difference between 211 and 60 degrees and it will give you an idea what, say, a 5 degree difference will do.

2) Syrup boiling is around 219 degrees-- that's boiling. When it's in the hydrometer cup it is NOT boiling so it's less than the 219 it started out at and since that tall cup has so much surface areas it loses that heat very quickly-- that's why you need to test within 10 or so seconds of filling the cup. I find that by the time I put in a thermometer and try to get get a good reading, it's too late.

Another thing to watch for is getting syrup on the hydrometer above the test line. This will weigh down the hydrometer and give a thin reading. I usually rinse and dry the hydrometer between tests.

PerryW
03-16-2009, 03:14 PM
Sticky,

Isn't the hydrometer supposed to be used at certain exact temps? Mine says 211 degrees with a red line and 60 cold test line. How critical is that 211? I am scooping it up at between 215-220 but as soon as removed from heat it drops below 200 very quickly.

temp Syrup Density ( Baume)
209 -- 32.0
202 -- 32.25
193 -- 32.50
185 -- 32.75
176 -- 33.00

140 -- 34.0

60 -- 36.0


Trust your hydrometer. Use it to calibrate your thermometer for each boil (not vice versa).

I usually take a couple consecutive measurements so the cup is hot and it doesn't cool down the syrup too quick.

clafarr
03-23-2009, 02:33 PM
boiling temps will change a little bit with the barometer each day. good luck