Tip toeing into cider / wine

Have my first batch going on it’s first ferment.

I am on day 15 and the airlock is burping every 10 to 17 seconds.

At what point do I deceid the first ferment is done?  Is it a hard x days?  Airlock burping slowed to a certain time frame?  Stop burping all together?
Brewers choice?

Thanks

Are you using carboys or see through hopper style?
You'll want ghe kraeusen and yeast to settle.
Gas venting should be almost non-existent.
You can stop it earlier and it'll usually be a bit sweater, as the yeast hasn't converted all the sugar.

Eta: you should also be checking terminal gravity.

I am using the white six gallon food grade brewing bucket with the lid with a grommet hole for the airlock.

So I don’t have any passive insight on what is going on with the current ferment.

I bought a hydrometer after I started fermentation, so I don’t have the starting gravity number but I do have a way to measure it.

How much harm will come if I pop the lid open, look at it, take a gravity reading and put the lid back on?

No harm at all. Just get a whine thief to gently take a sample for your reading

If you still have that much gas, I'd let it be.
Is it going longer than the recipe you're following?
Is your temp close?
You should be fine, though.

I've had mashes go 2 weeks longer than they usually do (same recipe) and turned out no different flavor.

recipe...hmmm...well...

I’m just winging it ( may not be the best approach)

From reading various recipes, it appeared that a ratio of:
one gallon of apple juice (in its purest form you can get)
To one pound of sugar
Add yeast

I sanitized all my gear

bought five gallons of apple juice (first) then decided I wanted to use brown sugar.  I learned my local store only had brown sugar in two pound bags.  So I only went with four pounds of brown sugar.

warmed one gallon of juice to 100 degrees, added / de solved the four pounds of sugar in the juice.  Then added my yeast Lalvin K1-1116(?)

Tempered the one gallon with the remaining juice then tossed the lid on with the air lock and let it set.

Activity started 48 hours later.

Room temp could be better, it’s in my basement and the temp down there is anywhere from 59 to 65.

That thing is producing a bunch of gas, so at this point, I am tempted just to leave it alone for a while.

With your given recipe, you're @ <10% abv.
I'd let it sit.

A couple things to consider-

1) You shouldn't be pitching the yeast at that temperature. Realize that there is a delta between liquid temp (95-100 degrees) and yeast temp (which was probably room temperature). Yeast don't much like sudden temperature changes. If you would have added the yeast after you mixed the warm/sweet with the apple juice, that would have been better.

2) Depending on the yeast, some will really struggle at 58 degrees. At least the fermentation action creates a little bit of heat. You might consider a warmer place

Gravity is key. Many wine recipes will ferment to 'dry'. I've seen 1.000 - 0.994 on a hydrometer. When the gravity is stable for 2 days in a row, it's likely not fermenting any longer.
It can continue to bubble a little after fermentation as CO2 comes out of solution.

If you want to make a carbonated cider, you'll rack this into the bottling bucket, add your priming sugar, and then bottle (if you are bottle conditioning)
If you want to make a still, sweet cider (apple wine), you'll transfer to secondary fermenter, mix in an appropriate amount of Potassium Sorbate and Potassium Metabisulfite, and then mix in sugar or honey to your taste.

Can someone more knowledgeable than me address to sulfur compounds you get with cider? I've only done one batch and it's wasn't very noticeable, but it was there.

There are several articles about this when you google search "sulfur compounds in cider". I believe you could reduce sulfur production by adding appropriate yeast nutrient.

Wait a month.  Then another month,  then transfer,  and wait 3 months.

@djkest @Sixpack595

Sulfur Compounds in Cider are commonly referred to as Volatile Sulfur Compounds (VSC's). They can be caused by numerous things, to include sprays in the orchards/vineyards, the strain of yeast used, how the yeast was handled (yeast stress), the profile of nitrogenous sources (AKA Yeast Assimable Nitrogen), fermentation kinetics, etc.

Most hobbyists and even a large portion of the commercial world do not measure YAN, to the great frustration of people in my line of work (technical fermentation/consulting). Generally speaking, you need about 10ppm of YAN for each % of potential alcohol. YAN is just a combination of the inorganic nitrogen (as ammonia) and the organic sources (amino acids and the like). Current research is driving the consensus that organic nutrition is better in almost every way, except price. Commercially, you will find that DAP (Diammonium Phosphate) is WAY cheaper per ppm of YAN compared to Fermaid O.

Cider has very low native levels of YAN, combine this with a more "simple" aromatic matrix compared to wine; and VSC's stand out like a sore thumb.

The two best ways to prevent most VSC development are to use proper nutrition and a low/no sulfur producing yeast.

Proper nutrition looks like using a Yeast rehydration nutrient such as GoFerm (follow the directions) and supplementing the fermentation with Fermaid O. There are plenty of suppliers of low/no sulfur producing yeasts, with various levels of performance. For security, I would recommend a champagne strain, typically S. Bayanus.

Pretty much.