Hydrometer says syrup when temp is +10 ???

[mathprofdk]

We boiled down about 30 gallons of silver maple sap (between 1 and 2.5%) this weekend to about 1/2 gallon of near syrup. I bought a hydrometer this year, and was ready to use that. Water boiled at 210, so I figured I'd start checking around 217. It wasn't close until 219, and not exactly where it needed to be (top red line that reads "hot syrup at 211F") until 220.

This is only my second year, and first with the hydrometer. What's happening? I have a CDN digital thermometer that I thought was working well, but I'm guessing that's the weak link.

Thoughts?
~DK

[jmp]

Sounds like you did everything right. As you know boiling point of water changes with barometric pressure.

[johnallin]

Don't feel bad, we never seem to get syrup until we see 220 to 222. Don't know why, but that's the way it is. Your hydrometer is the only true test; the thermometer is only a refference point and lets you know when it's time to stand up and pay attention.

[RileySugarbush]

Weird isn't it? We see similar things, drawing off slightly thick syrup at 221/222 on our digital thermometer.

[PerryW]

for the record, the reason the Hyrometer Hot Test is listed at 211 deg is to allow for small amount of cooling while filling the hydrometer cup and taking the reading.

But is really doesn't make that much difference. As long as the syrup is over 205 degrees or so, the Upper Red Line is accurate.

[MustardSeedMum]

I have a CDN digital thermometer that I thought was working well, but I'm guessing that's the weak link.
~DK

Is CDN a brand? Or did you mean "canadian"? Be careful now, I'm Cdn. ;)

Strangely though, this evening the same thing happened to me. I got a +10. Shocking.
I have a CHINESE candy thermometer. Maybe that's my weak link. :lol: Oh, I can say that because I'm chinese cdn, although not from China.

OK. I really should get some zz's. I'm tired from an all day boil and I'm cracking bad jokes.

[Bucket Head]

Just go with what the hydrometer says. I don't know who came up with the "seven degrees over the boiling point of water" thing, but their wrong! Water boils here right around 209-210 and we never have syrup at anything less than 218-219. We made lots of " almost syrup" by going with that seven degree thing on a thermometer. Nine degrees over is what we shoot for and then we are pretty close.

Steve

[PerryW]

The 7.1 degree thing is actually something that has been measured in the lab. But I have a feeling that a random digital thermometer from China may not be suited to read the foaming boil of syrup accurately.


Aslo, my evaporator has a big dial thermometer that you can read from across the sugarhouse. There are only two numbers on it. O and 7. It's designed to read the temp at the drawoff of the pan and designed for syrup.

[MapleMoonChaos]

Just go with what the hydrometer says. I don't know who came up with the "seven degrees over the boiling point of water" thing, but their wrong! Water boils here right around 209-210 and we never have syrup at anything less than 218-219. We made lots of " almost syrup" by going with that seven degree thing on a thermometer. Nine degrees over is what we shoot for and then we are pretty close.

Steve


i'll second that. my water usually boils around 209,210-210.5 and i always have to go up to about 219.5 before my syrup is finished, but i suppose it could also be my thermometer is inaccurate.

[Vermont Creation Hardwood]

I have exactly the same problem. The interesting thing is that all these Chinese thermometers are reading high if the 7.1 measurement is truly accurate.

[PapaSmiff]

Could increased humidity in the sugarhouse be changing the temperature at which water boils? Does it boil at a higher temperature in high humidity? If so, perhaps you are checking the temperature of boiling water when the air is dry. But after boiling for a long time, the humidity goes up, so does the temperature of boiling water also go up? Just a thought.

[PerryW]

Could increased humidity in the sugarhouse be changing the temperature at which water boils? Does it boil at a higher temperature in high humidity? If so, perhaps you are checking the temperature of boiling water when the air is dry. But after boiling for a long time, the humidity goes up, so does the temperature of boiling water also go up? Just a thought.

I don't think so since the probe of the thermometer is essentially always at 100% humidity when immersed in water or sap.

[johnallin]

Since the Leader brand dial thermometers are adjustable - zero out for boiling water dailly? - the 7 mark is really a moving target. I gave up a long time ago and just start paying attention when we hit the "7" and begin testing with the hydro. As stated though; I don't remember ever pulling syrup at that number and it always seems to be about 3-4 points over that. It's not the final word for syrup, but i would be lost without it.

[PerryW]

I also leave my dial thermometer alone (never adjust it). Some days syrup comes off at 6.5 some days it comes off at 8.0.

The dial thermometer also is more sluggish than the hydrometer. As I draw off a batch, I am constantly intercepting the flow of syrup into the filter/canner and taking several hydrometer reading during the drawoff. I will notice the hydrometer dropping well below syrup but the dial is still reading syrup.

[mathprofdk]

Thanks, everyone. That's quite a relief. And it's funny - I'm glad everyone enjoyed the "almost syrup" I gave them last year!

Just to be clear, the risk of not going all the way is... what? That it'll spoil sooner? And if you go too far... you get crystals after a while?

Oh, and CDN is the brand name. I have nothing against my Canadian neighbors. ;-) (Though now that I moved from MN to IL, they're not really neighbors anymore!)

Thanks,
~DK

[PerryW]

yes, too thin syrup can ferment.

[danno]

I've got two thermos in my syrup pan near my draw off. The tips of the probes are about an inch away from each other. They read a good 3 degrees different. The dial thermo installed in pan reads syrup at 221, the autodraw digital was reading 218.3 for syrup last night per the hydro. They say the paper in the hydro can shift - a second or third hydro in the sugarhouse is a good idea to convince you that the first one is in fact correct:) And also as a backup when the first one breaks.

[adk1]

I have been messing with the same thing. I have a 5" dial Leader Thermometer. I calibrate at the startup of every boil to the 0 for boiling water. I am also starting to pay attention once the thermometer reads the 7 or 7 degrees above the boiling point of water for that day. I will check with hydro constantly. IT seems to take awhile to get above the 7. The last time I drew off I was slightly below the 211 hot test line of the hydro.. I use my dipper to get the sheeting off of the syrup. I just like doing this.

My first batch I was pretty conservative and didnt draw off until I was floating that 211 red line..I probably took too much time checking..WHen I got the batch back in the house, and tested it at 60 degrees, it had a 69 brix...SO I decided on the second boil to take off before the red line was entirely floating..When I got back in and tested at 60 degrees I tested at 65 brix! I would rather be heavy but, I will use this syrup for cream or something. I hope the third time is a charm, I am learning alot that is for sure.

[PerryW]

I draw off directly into my 12x20 filter canner, but continuously take hydrometer readings throughout the drawoff so I know when to close the valve. Each takeoff is different. Some are picture perfect, where each hydro cup is right on the red line and the whole takeoff seems right on the money. On other takeoffs, the hydro reading climb up a point or more (baume) and I compensate by running some thinner syrup in afterwards.

BUT, since I put all my syrup in 5 gal containers, I can do my actual standardization of the syrup under less hectic (and more hygienic) conditions. One thing I have noticed, is that my syrup in the drums is almost always too thick and I end up adding water in the canning process to bring it back down to syrup.

[Bucket Head]

I'm not argueing Perry, but where was this lab that the 7.1 was tested? I want to talk to these people! Were they sober when the tests were being conducted? Lol! Seriously, that seven degree thing caused me a lot of frustration until I did my own "tests" and determined it was'nt working. Trying to make the correct density syrup twice was a lot of extra work!

Steve

[PerryW]

I'm not argueing Perry, but where was this lab that the 7.1 was tested? I want to talk to these people! Were they sober when the tests were being conducted? Lol! Seriously, that seven degree thing caused me a lot of frustration until I did my own "tests" and determined it was'nt working. Trying to make the correct density syrup twice was a lot of extra work!

Steve

Steve, I don't believe they were drunk during testing but I was most likely drunk when I read the report.