I don’t have a candy thermometer. I had one for a while, but it never seemed to be ‘right’. See, I learned the ‘other way’ to check sugar candy while cooking. When I used the thermometer it’d say such and so range was “soft ball” – but the other way check didn’t quite match, and worse it’d hit the stage at different temps at various times.
I figured out why, eventually, and I’ll even share in a bit, but I thought I’d wander through the old-fashioned measurements a bit. I’ll begin with a bit of explanation.
Candy-making begins with adding some liquid to sugar. You may (almost certainly will) add a bit of flavor to it as well, but that’s incidental. You then heat it to drive out the water. If you used something besides water (unless it’s alcohol, and I do NOT recommend using that) you’re still just driving out the water — the rest of what was in it remains as flavor. I’ll point out that if you use something like an essential oil, that’s going to leave as well while you’re cooking.
Anyway, the old-fashioned test is to drizzle a bit of what’s boiling into cold (tap-water cold) water and see what it does.
The very first thing it’ll do is dissolve out into the water. You get this cloud.
The next stage is the lowest ‘candy’ stage. It’s called thread. When you drizzle your liquid into cold water it’ll stay cohesive as it enters the water and goes to the bottom. However, when you prod at the thread with your finger or a blunt object it’ll just move around, maybe dissolving. You’ll get what I mean when we go to the next stage.
And that next stage is soft ball. Now when you prod that thread it’ll join and mound. In fact you can form it into a bit of a ball. However, if you then pull that ball out of the water it’ll collapse to an ooze (or a soft pancake depending how close it’s coming to the next stage).
Firm ball comes next, and now when you pull it out of the water it stays sort of ball-like. Again depending on where in the range it might slightly flatten but still remain a ball but is still fairly easy to flatten with pressure. Actually, when I was growing up I got another test to use at this point. Pull out a plate or a saucer and drop the ball, listening for the impact. At firm ball the impact is more of a “plop” instead of a “clank”. (Think the sound of taffy hitting a plate over the sound of a candy cane doing the same. Oh – don’t be fooled, this is not the right temperature for taffy, and the next stage isn’t right for hard candies. I’m just trying to give you a feel for the sound.)
Hard ball is next, and obviously it’s a lot harder to flatten. In fact it’s beginning to resist being formed into a ball – not like the earlier thread stage of not holding together but rather being hard already. You can, however, still form it. When it comes out of the water it keeps its form unless pressure is applied, but it’ll still squeeze. Dropped on the saucer it clanks more than plops.
Two more stages while we’re driving out water: soft and hard crack. In both the thread you drop will harden too much for you to then form it into a ball. You pull out the thread and try to bend it for the test. Soft crack the thread bends some before breaking. Hard crack doesn’t bend at all; it just breaks. Please, please, PLEASE… do NOT grab either of these with your fingers immediately after pouring them into the water. Give it a moment or three to cool enough to handle. Sugar at this temperature will raise major burns. Because it’s sticky as well as dense it’ll cling and hold heat for lots of time while burning you.
Around this point you have driven out all the water. You have entered the ‘making caramel’ stage. No, not those soft caramels you use to wrap around apples. This is the stuff you find on caramel corn – hard, crisp candy coatings. At this point all the flavor is coming from chemical changes as the sugar heads toward burning. If you’re going here you want to stir pretty much constantly, watching it like a hawk. The darker it gets the richer the resulting flavor will be, but the instant any of it burns it’s all ruined – the ashy taste will permeate the entire batch and overwhelm all other flavors. But I’ve moved past my point.
As I said near the beginning, I kept getting differences on my thermometer, but I finally figured out why. The first thing is the fact that I’d be cooking at different places – places at different altitudes. 500 feet is one degree F, and that assumes the weather (and subsequent barometric pressure for OTHER than gravity) is the same. Make it during a rainstorm and the temperature is different than that made during a bright sunshiny day – probably.
The second thing is that the temperature in the pot isn’t equitable. There’s a bit of chaos in there, and spots next to the burner (or cladding if using something to equalize) are hotter than that next to the middle, which in turn is hotter than the spots next to the side. Add to this the fact that most thermometers are cooler themselves – due to the fact they act as radiators from sticking outside the pot – and so form a bit of a protective layer that buffers the temperature. But this layer will dissolve and reform, so…
Bottom line, you CAN trust the thermometer, but not perfectly. You need to use it the same way each time, you need to be aware of the effects of weather conditions, you need to have calibrated it (is 350F on this one hard or firm – or even still thread?). Oh, and unless you’re making so much so frequently you have a constant reference point to all that, you should go ahead and back-stop your thermometer with a cold-water test.
OK, let’s add some information. See, if I was advising a new cook or someone who really hadn’t messed with cooking candy before, I’d advise them to get a thermometer anyway. They’d use it to watch for approximately when to start testing stages.
I’d also advise them that I know they don’t really ‘get’ what hard ball, soft ball, and so on really are, and that it’ll come with practice. They’re just going to have to make several batches of candy and SOMEHOW get rid of the sticky, sweet, delicious but not-the-right-consistency “mistakes”. (I made lots of batches of fudge topping for ice cream this way. [sarcasm] Such labor, getting rid of all those mistakes. [end sarcasm] grin)
Once they’ve got there, I’d add the next layer of lesson – the reason I don’t need a thermometer to know ‘when’ to start testing so much. Learn to watch the bubbles. The bubbles get smaller and smaller and at the same time lift higher and higher in the pan – to a point. (caramel. sigh) Eventually you learn to say, “Now. Now is when I need to start testing.”
Later I’ll discuss fudge, with recipe. For now, however, go enjoy yourselves.