Fermentation: how make naturally carbonated beverages that are sweet?
September 15, 2016 4:04 AM   Subscribe

I've been making ginger beer naturally, using a ginger bug in swing top bottles. My goal is to get a dry, very fizzy ginger beverage. I'm wondering if it's possible to do this and have the beverage be mostly dry, but not completely devoid of sugar.

There are 2 common types of in-bottle fermented beverages made commercially: beer and sparkling wine. I feel like I understand what's going on with beer. Sugar is added for a secondary in-bottle fermentation. There are tables that will tell you, given the temperature, how much sugar/L is needed to get the carbonation you want. The yeasts run out of sugar and the fermentation stops. That's fine for beer, because beer isn't supposed to be sweet.

I've used this method for ginger beer, and ended up with 0.5L bottles of something similar to sparkling wine. Good flavor, <2% alcohol, and carbonation very much like what you'd get in Champagne. Except it's overly dry.

This prompts my question: How can it be that Champagne can be sweet? Why don't all the sugars convert to alcohol?

Is it the alcohol content killing the yeasts?

Does the fermentation eventually get stuck due to a total lack oxygen?

Do winemakers even have any control over this at all? Is it just a matter of bottling, letting the yeasts do their thing, and hoping some sugars remain?

FWIW, I am aware of the dangers of overpressurization. I don't have champagne bottles. If I just add more sugar before bottling, I'm concerned that the swing top bottles I'm working with may explode -- and even then, it doesn't explain why eventually those sugars wouldn't be converted anyway.
posted by cotterpin to Food & Drink (13 answers total) 5 users marked this as a favorite
I believe there are non fermentable sugars - or at least things that taste sweet that yeast does not eat. Traditionally lactose is used to make milk stouts sweet and I've heard of people people using Splenda to sweeten cider.
posted by phil at 4:40 AM on September 15, 2016 [1 favorite]

If you do use lactose, keep in mind that it is significantly less sweet than table sugar per ounce. I might try stevia or splenda or something.

A couple of other options are to stop the yeast from working either by pasteurizing or refrigerating. After bottling, crack a bottle open periodically (once a day maybe) and stop the yeast once you've reached the right mix of carbonation and sweetness. You should start with a uniform batch having an even mix of yeast and sugar in all the bottles. It can help to include one or more plastic bottles in the batch that you can feel to ascertain pressure — you can reuse soda or seltzer bottles. If you use refrigeration, obviously they must be kept cold or the yeast can wake up and start making more CO2 from the sugar. Pasteurizing can be a pain (keeping each bottle in a big pot of hot water long enough to kill the yeast) but then your product will be shelf-stable.
posted by exogenous at 5:03 AM on September 15, 2016 [1 favorite]

Some sweeter champagne is sweeter because sugar is added to the final product.
posted by Jahaza at 5:25 AM on September 15, 2016 [1 favorite]

From what I know from making beer-beer, different strains of yeast have different tolerances for alcohol. So if the alcohol level gets higher than the yeast can withstand before the yeast has consumed all of the available sugar, there would be some sugar left behind.

+1 for refrigerating it part way through fermentation; and some experimenting with the amount of sugar you start with - adding more sugar or fermenting for less time would get you closer to sweet.

I'd suggest figuring out how long it takes to get something that's sparkling enough, and then increasing the amount of sugar until it's as sweet as you'd like.
posted by ambilevous at 6:10 AM on September 15, 2016 [1 favorite]

Sweet champagne is made by adding sugar or sweetened wine during the top-up (dosage) after removing the spent yeast (disgorgement).

Many dessert wines stop fermenting because the alcohol kills the yeast; these will end up with anywhere from 13 to 15 pct abv. Fortified wines such as port go one step further, adding brandy to raise the alcohol to 18 pct or so.

There are some sweet wines with lower alchohol, in particular this is true of many German kabinets and spatlese. Historically, this might have been the result of fermentation stopping because the cellar temperature dropped too low, but wines made this way would tend to re-ferment in the bottle. Nowadays it is common practice to use sterile filtration before bottling. Sometimes unfermented grape juice is added after filtration to boost the sweetness (called süssreserve in German)

Most traditional ciders are dry; I imagine modern sweet-ish ciders are made using some manipulation similar to the above.
posted by mr vino at 6:26 AM on September 15, 2016

I make hard cider, which has a similar issue. The only real way to have a sweet or semi-sweet cider without artificial sweeteners or preservatives is to pasteurize once you've achieved the carbonation level you want. For me, after I bottle, I wait a few days and then open a bottle every day until it's carbonated, and then I run the rest of the bottles through the dishwasher (regular cycle, no drying). I haven't had any issues with the pasteurized bottles, and in six years, I've only once waited too long and had bottles explode in the dishwasher.

You can refrigerate to halt the yeast (note that this won't kill the yeast), but you will have to refrigerate the entire batch.

It's too risky to try and hope the yeast reaches its alcohol tolerance and dies off when your abv is that low. If you try to stress the yeast, you will most likely end up with a stuck fermentation that produces off flavors but can still ferment the extra sugar you add.

BTW, beer is actually fairly sweet, but the carbonation hides it. Beer contains unfermentable sugars, which isn't the case with simpler alcohols like cider (not sure about ginger beer). So if you want a more carbonated final product, you might have to add what seems like too much sugar when you bottle.
posted by autolykos at 6:36 AM on September 15, 2016

The big one you seem to be missing is kombucha. It's not ginger beer, but I can easily use a kombucha base to make a fizzy ginger beverage that ranges from very sweet to very tart, doing secondary fermentation in a swing top. I can explain more if you're interested in that approach.
posted by SaltySalticid at 7:05 AM on September 15, 2016 [2 favorites]

One approach commonly used by homebrewers is to refrigerate the product to make the yeast go dormant, adding potassium sorbate, then adding sugar to sweeten. The potassium sorbate will prevent the yeast from waking back up.

It can be a little tricky because if the yeast are not fully dormant or if you don't add enough potassium sorbate, then the yeast can wake up, metabolize the potassium sorbate, and produce an off-flavor.

The downside to the sorbate approach is that you have to carbonate the product yourself rather than relying on the yeast to do the job.
posted by jedicus at 7:10 AM on September 15, 2016

I think all the sugars are basically coming from added cane sugar during the initial brew. I'm making a concentrated sweet ginger tea (about 5% by weight sugar) and letting that ferment with a natrual starter made from the yeasts on ginger skins.

A few different ginger beer recipes I've read have said to sweeten to taste, bottle at the peak of the primary fermentation, and refrigerate asap when the bottles are carbonated (testing single bottles or using a plastic control). My fridge just does not have the space for this. I'd like to get something shelf stable and naturally carbonated without explosions.

I'm doubt that I can open the bottles to kill the yeasts and still keep the carbonation. Though the champagne "dosage" is interesting and the missing concept I don't think I can do much.

autolykos - to pasteurize in-the bottles is worth a try.

SaltySalticid - you're right, I forgot about kombucha. Ironically it's probably the closest thing to what I'm trying to do. Could you explain or send me a link?
posted by cotterpin at 8:09 AM on September 15, 2016

That's fine for beer, because beer isn't supposed to be sweet.

Some beers are supposed to be sweet, and various sugar sources are used to achieve that in different ways. For what you're trying to do, I'd look into replacing some of the sugar bill with less fermentable sugars like honey or molasses. I'd also consider looking into using unpasteurized honey specifically for the purposes of retarding fermentation.

Speaking of honey - mead is something that ranges from dry to sweet and the most basic method pretty much just relies on providing more sugar than the yeast can handle.

Part of what's probably causing you trouble is that your wild starter doesn't have the same known properties that the nice commercial yeast packages do, so you don't know exactly how much sugar will get you bubbles without bombs. So you'll need to experiment with combinations of: upping the total sugar, reducing the amount of yeast, adding non-fermentable sugars, lowering fermentation temperature, adding fermentation retardants, etc.

I haven't read this book, but the authors (a professional brewer and the CEO of a respected yeast producer) know their stuff. It's based around beer brewing but the basic yeast biology should help guide you in your trials.
posted by sparklemotion at 8:43 AM on September 15, 2016 [1 favorite]

My father made fermented apple juice, result being...apple wine, I guess. He had water traps that let excess co2 go away rather than carbonating beverage.

He used a hygrometer to measure density and therefore sugar content. He had different jugs with different sugar levels for experimentation. I don't actually remember, but I believe he got the different sugar levels by adding table sugar.

After the fermentation raises the alcohol content to a certain level (about 12% IIRC), the yeast dies. You get a sweet result depending on how much sugar is left.
posted by SemiSalt at 8:59 AM on September 15, 2016

Some time ago I talked to a local brewer friend-of-a-friend about a similar idea. At the time I was introducing sourdough and/or yogurt cultures into my ginger beer with the goal of favoring an acidic fermentation over an alcoholic one (rather like kombucha, I guess). He suggested that I might be able to find a culture that doesn't tolerate acidity well and start with a low pH so that as fermentation progressed and the solution becomes more acidic, the culture would die off or go dormant. I never got around to it, but it might be something for you to look into.
posted by sibilatorix at 12:59 PM on September 15, 2016 [1 favorite]

Thank you all for the links, there's a lot of useful things to digest here and I've learned something.
posted by cotterpin at 1:39 AM on September 16, 2016

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