Diet Soda Without Forced Carbonation

I've recently started brewing my own cider and graff and am enjoying that and would like to branch out into soda as well. I made a batch of ginger ale tonight according to the pretty basic recipe into a growler and, if that goes well, will probably make more. However, what I'm really after ties into a household-level addiction.

We drink a LOT of diet soda in our house, nearly all of it root beer. I'd love to replace a large chunk of that with homebrew diet root beer. At the moment, I have no plans to add any CO2 tank setup, so I'm looking for ratios to make "foolproof" homebrew diet root beer that won't lead to bottle bombs.

For sweetening, I'll be using stevia powder, which I already use to make my own diet sweet tea for most of the summer. So, what I'm trying to figure out is exactly how much sugar to add to the batches to just get the right amount of carbonation and then have the sugar run out.

Am I right in looking at carbonation calculators like this one:

http://hbd.org/cgi-bin/recipator/brew/widgets/bp.html

and putting in 4 volumes of CO2, my room temp and the volume of soda to get the amount of sugar to carbonate and then starve off the yeast?

So, for a 2L bottle of stevia-sweetened soda, at 68F, to get to 4x CO2, I'd use 0.846 oz of sucrose?

And, once that sits for a few days, all of that sugar will be gone and the bottles will stabilize and no longer ferment?

While I intend to refrigerate, and would obviously still need to deal with spoilage issues, am I right in thinking I could leave them sit out at room temperature without risk of explosion?

I believe the science says so, but want a bit more confirmation that I'm on the right track. Thoughts?

I dug a little deeper and found the exact equation I was looking for here:
http://hbd.org/brewery/library/YPrimerMH.html

The relevant sentence is:

"Determining the amount of priming sugar is based on the fact that adding 4 grams of sucrose (cane/beet/granulated sugar) per litre will ferment to give 1 volume of CO2:
4 g/l (1/2 oz/US gal) sucrose --> 1 vol. CO2"

I'm just going to use that 4g sugar to 1L water ratio and go from there.

looks like you got it right, the online calculators assume, given a temp, a residual amount of CO2 in solution, so if you had followed them you would always undercarbonate your soda


Id be interested in hearing how this turned out, although Im not a big fan of stevia, it tastes too much like aspartame to me.....

Yeah. That calculator assumes up to 1 volume of CO2 already in the liquid, so I'll just compensate with one extra (plus, I like soda fizzy).

I know a lot of people don't like stevia, but I like the fact that it's just a straight extract from a plant instead of a heavily modified/engineered chemical from a lab.

My biggest concern is that the priming-only sugar won't be enough to kick-start the yeast activity. I just mixed up a batch tonight, to test out this whole approach and whether my concern is valid.

I mixed up 5 gallons and added 40 g of sugar and most of a bag of Splenda (the sugar equiv that measures cup for cup like sugar).
To one of the gallons, I added another 8g of sugar.
To another I added 16g of sugar.

To each gallon, I added 1/8tsp of yeast.

They're sitting out and we'll see how it goes.

Some say that the artificial sweeteners are bad for you and could cause cancer. I know if I chew too much gum with artificial sweeteners, I'll get a headache. I would stick to drinking lots of water, milk, 100% fruit juices and tea.

First of all, stevia isn't an artificial sweetener. It's directly taken from a plant, just like the rest of our brewing ingredients. That's part of why I want to use it as my sweetener for sodas going forward. Splenda was convenient and measures like sugar for making the recipe conversion easy for the first batch.

Second, "some say" that artificial sweeteners are bad for you, but those same "some" unfortunately don't have a lot of science backing them. Every time scientists try to prove the anecdotal stuff the "some" claim, they come up empty or with very little danger.

Saccharin, was, in fact, proven to cause cancer in rats, but the experiment was done with such high dosages, you'd have to be eating the stuff with a shovel to reach the same level yourself.

As far as your own personal experience, I can't say what's going on. I could counter with my own story that I drink 6-8 cans of diet soda a day and I never get headaches that have any correlation to when I drink them.

Heck, a commercial bottle of beer has a warning on it that says that drinking beer might be bad for your health, despite ALL of the evidence that studies summarized here have to say otherwise: http://www2.potsdam.edu/hansondj/AlcoholAndHealth.html

You can feel free to stick with whatever you like, but I'm sticking with what can actually be proven in a lab.

How did the diet root beer come out? You are on the right track - I picked up some Rainbow root beer and cola extract, and they both had diet soda recipes (or low cal, or whatever). The general idea in the instructions is exactly the same idea you posted. Use a little sugar for the carbonation, then use artifical sweeteners (or stevia!) for the rest.

Anyway - let me know how it worked out. I want to try it. I hesitate to post their recipe on line, but 4 to 6 tablespoons of sugar per gallon of mix seems to be the magic number, with 1/8 to 1/4 teaspoon of yeast.

Is that close to what your research shows?

The batch I tried didn't work out too well, but I believe that was mostly because of the containers I tried to use to let it carbonate in. I tried to re-use some apple cider containers I had sitting on the counter from my most recent batch of hard cider. They were too soft and I believe the caps leaked pressure.

I tried the "official" ratios of sugar and a bit more in a few of the gallons. All carbonated a tiny bit, but none had anything close to "acceptable" levels of carbonation for a root beer.

I want to try another batch to be sure, but at the same time, I'm starting to lean toward a kegging setup for other reasons, so it remains to be seen whether that effort will destroy my desire to figure this out.

The other upside to kegging is you can just run carbed water and use syrups (homemade or otherwise). I recently switched to that route and it works great.

Yeah. The upsides of kegging are clear on many fronts, with the soda benefits being just a small portion.

It's been more about the space for a kegerator, the cost of said kegerator, spousal agreement, etc.

I got the kegging setup and a kegerator, so I'm now going to be going the easy route of making quick diet root beer and force carbing it or just making syrup and mixing it in the glass with carbed water.