Can my evaporator run too hot?

[Ridgerun]

Last season I bought a new air tight, wood fired 2 by 8 with a blower, a preheater and a hood, made by A&A Metal, a very small company in PA. Compared to my old evaporator, it runs very hot and boils very hard, but I made very dark syrup. My question is, can evaporator boil too hard and run too hot?

[red maples]

I don't think so. I have talked to some folks that have grown to bigger evaps(bigger that 2 and 2.5 x 8's) and most have said that smaller rigs produce darker syrup. In one of Glen Goodrich classes about proper boiling he said he gives credit to the smaller operations that run smaller evaps because they are very difficult to run from consistant firing mixing maintaining proper boil through out the evap. etc etc etc. With his vast experience he said its Easier to boil on a bigger evap.

Now that being said last year was a dark year, for NH south of the lakes region. (not sure about north of the lakes) there was very little medium and mostly dark Amber and Grade B.

What some smaller evap guys are doing with good results which I am planning for 2016 season is run a forced air bubbler. running between the flues and in the syrup pan. This will help keep the grades lighter but I have also heard you still need to watch the flavors because you can make lighter syrup with a darker taste.

[nymapleguy607]

Making dark syrup wouldn't be caused by boiling too fast. Low sugar content in your sap and short boils adding a small amount of sap will cause your grade to darken. Last year was just a year where a lot of dark syrup was made. Running the evaporator too hot will just go through your wood pile quicker. If everything boils evenly and hard I would just let her rip.

[WESTVIRGINIAMAPLER]

NO, the hotter and faster you run it, the quicker it boils. I used to run mine as high as 1400 to 1750 stack temps and made lots of light syrup.

[maple flats]

You can't run too hot as long as the depth in the pan is at least 3/4". Just keep in sap/concentrate flowing in. The faster you boil and the longer the boil at a fast boil the lighter the syrup.

[killingworthmaple]

Sorry if this is a little off topic. I have a question about boiling hot also if I let my fire really rip the front syrup pan foams and I get nervous that I'm going to burn my pan. The question is if I'm boiling at 1.5-2 in. of sap in the front pan and it foams up to 3-4 in. high am I in danger or is that ok. I do add defoamer at a every firing. For you guys with experience how much foaming is ok and how much is too much. Thanks

Nathan

[jmayerl]

With defoamer that is about avg. late in season my last channel will consistently be at 10" or the top of the pan

[mellondome]

I rarely have Foam I the front pan... even with concentrate flowing into the back pan. I add 2 drops of defoamer to the float box every time I fire ... (5 to 7 min). It may help by not running your pans so deep. That air bubble has to rise to the surface to break... you can trap a lot of air in 2in of syrup..thus creating a lot of "foam" and slowing your boil rate. Try backing down to 1 in or even 3/4in. It will surprise you how much better it boils a d how much less foam you have.

[maple marc]

Yes, I believe you can run your evaporator too hot. I've done it with a 2x4. First year with it, no stack thermometer, 10" stack, plenty tall. We didn't know what we were doing--had never even seen an evaporator. My rep told me to run it with the draft door wide open. Ha.....Before we knew it, sap was spitting and spewing all over the shack, the stack and the door were glowing red. We called the rep to see if red metal was normal. "We don't sell to people who abuse their rig," was his reply. "Thanks a lot," I said. We got a stack thermometer, and we realized we were running above 1600 degrees. Way too hot--dangerous, and wasting a lot of wood. Think of the heat going up the stack. We had to run with the draft door completely closed and sealed with bricks to keep it running at a reasonable temperature. We had some really dry wood and too much stack for that little rig. Now we have a 2x6 and know better. 900-1000 degrees works well.

[Ridgerun]

Wow, great advice! Thank you everyone. It's reassuring to hear that many folks had darker syrup last year. Things got started very late here, and I think the sap was pretty watery. This year I plan to more closely monitor the sugar content of my sap. The advice I'm most excited about, though, is lowering the front pan level. I think mine has been much too high. Guess I need to be a little bolder. Thanks again, every one.

[nymapleguy607]

Just make sure the float arm for the front pan has enough travel to let sap in. If the sap isn't running in fast enough you will have a pan full of syrup that can scortch or burn very quickly. I run my syrup pan at about 1.5" Less than that is too close for comfort for me.

[killingworthmaple]

Thanks for the advise keep it coming.

Nathan

[Sugarmaker]

Maple marc is right on the mark. Yes you can fire the evaporator and get the arch and the stack to hot. Will the syrup and pans care? NO as long as they have fresh sap coming. Some light kindling is like rocket fuel and wit good draft natural or forced the stack can get red hot thT is TOOO HOT!
As for defomer use only enough to keep the foam down. a drop or two is usually more than enough about every time you fire.
You want the syrup to be boiling and defomer is not going to stop that from happening.
Regards,
Chris

[red maples]

yeah marc, that sound wierd, too long of a stack. burning hard wood? sounds like it. I insulated my doors on my arch front I can get the them glowing red, I believe cast iron glows at 1200 degrees. in the newer arches such as the hurricane etc. If I remember correctly those run about 1700* in the fire box. (but stack temps that high your heat is just going out the chimney) Every boil I spit sap out of my flue pan it boils very hard. I had to make splash guards for it. then I made a hood and no more problems.

my outer stack temps are optimal at between 6-700* I get the best boil for least amount of wood.
but its a matter of getting used to your rig to see what works best.

As for foam in syrup pans. YOU DON"T WANT FOAM IN YOUR SYRUP PAN OR FLUE PAN. If you have foam your not doing it right. Again from Glen Goodrich. if your defoaming correctly you shouldn't have foam in any pans. I generally run mine between 1 and 1.25 I might have 1 inch of foam in the flue pan. on the smaller rigs you may need to add a drop or 2 into the syrup pan now and again, especially when you are sweetening your pans and at the end of the season. As mentioned before if you have foam the moisture can't escape lowering you boiling rate. This is just my recommendation. when I am boiling I don't sit down. constantly watching everything. So nathan in my opinion you are running your pans too deep. I would run them at 1-1.25" and don't be afraid to add a little defoamer to the syrup pans to get the foam down.