Long time lurker - sulfite questions

[Theyeofra]

Heya guys.

I’ve been lurking for a long time. Almost every question was answered by the power of “search”

My first batch is fermenting nicely. Deets:
1 gallon organic apple juice
1 lb organic cane sugar
1/4 tsp yeast nutrient
1/2 packet EC-1118 yeast

I plan on adding another 1/4 tsp of nutrient on day 7 of fermentation for a staggered nutrient addition. Debating adding another 1/2 lb of sugar as well. But leaning to letting the 1118 ferment it completely dry on just the one lb of sugar. We are on day three.

My question is in regards to adding K metabisulfite when it’s time to rack. I have K meta powder. I couldn’t justify buying tablets when I could get a pound of k meta for $8. I have a milligram scale (accurate to the 0.001 of a gram) for dosage. What I need to know is how much pure kmeta powder (by weight) to use per gallon.

One website said 1.6g of kmeta per gallon produced 150ppm SO2. From what I read have read in a non real fruit containing must 50ppm is in the ballpark. So if that information is correct I would need 0.533g of kmeta per gallon to achieve 50ppm.

Is that correct? .5~ grams kmeta per gallon?

No k meta was added the the must pre pitch. It’s fermenting quite rapidly so I’m not too worried about infection at this point. That said I have no frame of reference since this is my first brew. I don’t want my cider to spoil during aging.

So bare bones. Should I add .5g Kmeta when I rack my cider?

Sorry for rambling. I’ve lurked so long it’s an avalanche post. Any pointers would be greatly appreciated.

Ra

 

[eebowler]

Wikipedia says: Campden tablets typically contain 0.44 g each of sodium metabisulfite (plus filler) and 8 of these are equivalent to one half level teaspoon (2.5 mL) of sodium metabisulfite.

Eckraus says:Potassium metabisulfite is slightly stronger than sodium metabisulfite by volume—17% stronger—but this is not enough to be taken into account if you are only making 5 or 10 gallons of wine at a time.

Hope this helps a little

 

[Theyeofra]

Hey thanks for the reply. I usually discount Wikipedia though. I am aware of the “activity” discrepancy with Na and K meta. Everything Ive read pointed to K meta being superior ( in concentration and lack of sodium) so I have potassium metabisulfite and conversions are irrelevant.

.44g sounds reasonable considering the data I’ve already collected.

 

[S-Met]

First, Welcome and congrats on your first cider being underway.

Opinion, but I never add K-Meta to store bought juice prefermentation. Just isn't necessary, unless you are using farm fresh pressed juice.

Post fermentation, your protocol sounds sufficient. There are a few threads on this forum that talk about the rate to add K-Meta based on PH. If you have a PH meter, check, but I wouldn't bother with the test strips.

 

[RPh_Guy]

says:Potassium metabisulfite is slightly stronger than sodium metabisulfite

Not true.

@Theyeofra
Check out this article:
https://***************.com/wiki/Sulfite
Still a work in progress, but it should help.

 

[jseyfert3]

1 gallon organic apple juice
1 lb organic cane sugar
...
Debating adding another 1/2 lb of sugar as well.

Wow! You must like it strong, since you're debating ~12 vs 15% ABV.

 

[Theyeofra]

Thanks for the link! I’m pretty excited about my first brew. Yes I have a digital pH meter, I’ll look into that for sure. Makes perfect sense.

Hehe I figured I would make a strong first batch. I think i will leave it with the one lb of sugar though. 15% would be a bit much methinks.

 

[jseyfert3]

Hehe I figured I would make a strong first batch. I think i will leave it with the one lb of sugar though. 15% would be a bit much methinks.

I'd say. I made some 7.5% stuff and that gets you after a few glasses...

From what I've read something in the 12% range will take a bit of aging to not be super harsh.

Do you have a hydrometer? Sounds like no, or if you do you didn't take a reading. Most juice is 1.045-1.055, my store bought stuff was 1.046 or so. A pound of table sugar adds 0.046 gravity per gallon of liquid. So if you have 1.050 from the juice and 0.046 from the sugar that's 1.096.

ABV is calculated from (IG - FG)*131.25, and FG is normally about 1.000. So 0.096*131.25 = 12.6% ABV, but you can't know for sure what you have unless you took a SG reading before you added yeast.

 

[Theyeofra]

Sadly my hydrometer arrived in several broken pieces. Same with the first fermenter I ordered. Now I have to order another one. I started without taking an SG reading because I figured ABV was irrelevant, I’ll just let it ferment dry and call it good.

I have sorbate as well if I feel like backsweetening. But I think I’ll leave it as is on this first attempt.

 

[gregbathurst]

The powder you buy is roughly 50% so2 so when you work out the dosage you double it for the actual addition. to avoid mistakes it is best to work in Litres and milligrams, so 50ppm is 50mg so2 or actually 100mg of powder /Litre. So a gallon is 4 litres and needs 400mg powder for 50ppm.

 

[Theyeofra]

I love the metric system!

The wiki article and that information completes the puzzle. Thanks guys! I appreciate it. I can work forward or backwards from those numbers.

 

[Epond83]

The campden tablets (Potassium Metabisulfite) I have weight out to .607g each, one per gallon. The info I have found say they create 75 ppm Sulfur Dioxide.