intense boil/foamy sap?

[tbear]

Hey Everyone,
I experienced something I've not seen before. I boil on a flat 2x5 Smoky Lake pan and corsair arch with a blower. I collected 200 gallons of older sap, it was crystal clear and tasted good as it had been frozen in the buckets most of the time. I boiled off 75 gallon the first day, it was little foamy which I suspected had to do with age, no biggie. The next day I went about boiling off the remaining 125 gallons. Here's what would happen: The timer would go off, I'd hit the blower switch, open the fire door and load it, hit the blower switch and reset the timer, by that time the boil would be trying to climb out of the pan! No, not just a little, it'd actually be at the top of the pan ready to spill over! There were a couple of times I had to open the fire door just to keep it from boiling over! So every six minutes (my firing schedule) I'd experience ten seconds of terror! It was not a fun day.

It wasn't the kind of foam that I'd skim out, the bubbles were small and filled with steam which makes me think it was the boil and not the foamy sap. I'd think it was close to syrup but I run the pan at one inch which keeps about 10 gallons of liquid in the pan so at 200 gallons there'd only be 5 gallons +- of syrup in the pan at the end of the boil. I was glad when that day was over. Anyone have any thoughts on why this might have happened? Thanks, Ted

[SeanD]

The biggest time I get major bubbling (like a bubble bath) is on the first boil when the sweet and pan have the least amount of defoamer in it. Once enough defoamer is in the pan, things settle down. It can sometimes happen after cleaning both pans, too but I only clean the back pan maybe once or not at all during the season.

The other time foaming can be an issue is when the bottom of your pan is caked up with cooked niter in the front pan. That's when the bubbles are greasy looking, tight, and defoamer has almost no effect on them.

I add defoamer after every firing, right after restarting the timer. If I forget on a cycle, I can tell on the next one or two because I'll have a larger amount of foam than usual in the last section of the flue pan and/or the very first section of the front pan. Are you using defoamer at regular intervals?

[tbear]

I use a few drops of oil to knock the "foam" down as needed, not necessarily at regular intervals. To be clear, this isn't the large Mr. Bubble bubbles, this looked like a very intense boil. It would start in the front of the pan then rapidly move the lenght of the pan to the back of the pan, then it would rise to the top of the pan immediately, setting things up for a boil over. As I've said, I'd never experienced anything like it before. I've only run 500/550 gallons of sap so far so I'm thinking nitre shouldn't be a problem, but, I've been wrong before so.... Thanks, Ted

Also, the oil (defoamer) didn't appear to slow it down at all.

[SeanD]

500 gallons is enough to need a cleaning for me. Are you boiling raw sap or concentrate? Run your finger on the bottom of the pan and see if you feel the smooth stainless or a rough baked-on layer of niter. Not sure why you've never experienced this before. Some years are worse than others for niter.

What kind of oil are you using? If it's a vegetable oil you need to use way more that traditional defoamer. I use canola. No matter what you use, it's recommended to use it at regular intervals. It's easier to get ahead foaming that trying to correct it. Again, if you've been doing it a certain way for some years I'm not sure why you are seeing something new.

[tbear]

I boil raw sap. I'll check for build up niter. I'm sure there's some but it hasn't been a problem in the past. I may just clean it, I really dont want to go through that boil again, if it was always like that I'd probably quit. It was an intense few hours. Thanks, ted

[tbear]

Thank you SeanD! It was the niter. I've been using this setup for 5 or 6 years and this was thre first time it's been a problem. Live and learn I guess. Thanks again, ted

[tcross]

it happens to me every year on the first boil or two. sometimes in the syrup pans, sometimes in the flue pan. i think it has something to do with the early sap composition? i also boil raw sap. after the first 2-3 runs it stops. its almost like bubble bath foam. it's white...ish/clear instead of syrup color. a drop of defoamer and it's usually gone and done with.

[SeanD]

Thank you SeanD! It was the niter. I've been using this setup for 5 or 6 years and this was thre first time it's been a problem. Live and learn I guess. Thanks again, ted

Glad it worked out for you.