My 2018 apple cider has an issue: It hardly fermented in the bottle at all (I use the French country style, where you "charge" each bottle with sugar and yeast, as you bottle it). While "still cider" is a thing in Europe (and it's a legitimate cider style), in the US most cider lovers want those bubbles.
At first I just discounted the cider in price, sold a quarter of it, and jumped into trying to figure out what happened. Then, I got creative about how to rescue the remaining cider:
What happened originally:
a. The cider itself (disregarding the bubbles is the best I've made. It's my first using crabapples and bittersweet apples, all from Epona Farm, in addition to the wonderful array of "sweet-sharp" heritage cider apples that were already here. It's the first to have some lactose added to it (dairy allergy alert), which is "milk sugar" and is unfermentable; I added it to provide just a bit of residual sugar which I thought the acidic juice needed, and it also provides a creaminess in the mouthfeel--more body. So far, so good. The cider tastes really great.
b. I put the clear, aged cider into a tank and added yeast and priming sugar calculated at 2 volumes of CO2. That is for the low-end of "sparkling" which is called "petaillant" by the French. So far, so good.
c. I tested the free sulfite and added just a touch, to get up to 45ppm, which was perfect for the cider's pH. This is what winemakers do, and for cider it is controversial: A few cidermakers sulfite their ciders, as it gives them more shelf-life (more microbial stability); in my defense, commercial yeasts can handle up to 50ppm sulfite, so I thought it would be OK. But most cidermakers do not sulfite before bottling. Here's why:
d. Steve Bader (owns wine/beer shop of that name; great guy and a great scholarly resource, and he runs an expertly-staffed and equipped shop) told me that the sulfite will scavenge all the O2 that's in the headspace. That was new to me and is an issue, because (as every winemaker and cidermaker should know) the yeast goes through two phases: first (the lag phase), the yeast multiply until they reach a density that satisfies them; and then (the fermentation phase) they start to convert sugar to ethyl alcohol, CO2, heat, and other byproducts (including sulfite, which is a natural component of any fermentation). If the free sulfite in the cider uses up the O2 in the headspace (under the crown cap), then the yeast can't multiply, and I'm not sure if they will then give up trying to multiply and start fermenting in tiny numbers? I think that is what happened, because when you open one of these ciders, it makes a faint hiss, and that is the CO2 escaping, and there are very faint and few bubbles rising in the liquid in your glass. I added enough priming sugar that there should be more hiss and more bubbles in the cider.
e. I waited 6 months before trying and selling the cider. Maybe if I wait longer, the few yeast in each bottle will finally make more CO2 and raise the carbonation level. BUT, apple cider has a shelf life and if it takes ?2? ?5? more years to finally get carbonated, the fruit flavor might be faded.
f. Another thing I think I did wrong is that I filled each bottle pretty full, leaving about 0.5" headspace (as we winemakers are supposed to do). I now know that some cidermakers leave 1.5" headspace, which gives more O2 to the yeast. As Steve noted, the O2 in the headspace doesn't raise spoilage issue because the yeast will use it up (during their lag phase) and then the headspace will be only CO2 after the in-bottle fermentation, which is a good preservative.
Dogged. So, for a month I've been reading about this, and thinking about what to do. Now, I'm working an experiment on my cider. This is what I just did to a 4-case test batch; I'll open a test bottle in about late July, to see if I have more carbonation then:
1. Open the bottles up and pour into carboys, leaving 20% of the inside carboy volume empty for lots of O2 space; cover with towel to allow more O2 to enter. Then I didn't want to rinse, wash, sulfite each bottle, so I stuck the empty bottles in the winery refrigerator, at 33F, thinking that would keep them "bugless."
2. Add more charging sugar in the carboys, calculated to raise the desired CO2 volume from 2 to 3.8 (4 volumes of CO2 is about the upper limit for in-bottle carbonation in a beer bottle). I was too cautious at 2 volumes.
3. Add K1V-1116 - the "killer yeast" (I used the workhorse EC-1118 yeast last time. I also added yeast nutrient; the yeast can't function well (or at all) if they don't have enough food. Well-cleared cider doesn't provide much nutrient to yeast.
4. Stir vigorously; lots of splashing.
5. Wait 24 hours with towel over carboy neck to allow O2 entry; then put on a ferm lock and test for evidence of renewed ferm.
6. This morning, each carboy was showing slight ferm, after about 16 hours (bubbling about every 40 seconds LOL). That was progress! I think it was so slight because that's not much sugar--not like the original ferm, and also because the yeast's lag phase is slower when I use a carboy, compared to using an open primary fermentation tank. I could've used a tank but that's more work and with lots of headspace in the carboy I thought I had this issue covered.
7. Re-bottle (with 1.5" headspace) and cap. I've learned to be very cautious and slow while capping, so that I can gently press down hard and get a tight seal, but without snapping off the bottle's neck.
If this re-done batch gives me good carb in-bottle, then I'll be pretty excited and will probably enter it in some competitions, because the taste is so good. We will know by late July maybe. If this works, I have about 12 more cases I can do the same to. THAT is the crazy part--opening a bottled cider and doing all this to it. It's more about learning, and maybe pride, than anything. It is not common at all to do this once you've closed a bottle. But, dogged.
