Grape juice wine experiment - Making wine in one bottle fast!

Here's the method:

Open juice bottle, add ingredients, cover the top with a paper towel or toilet paper and an elastic band. Put the bottle in a warm, dark place and leave it to ferment. After 4-5 days remove the paper and add an airlock or what is shown below.

I aim for 18 - 22 Celsius. Keeping it warm will ensure the yeast doesn't go dormant and will ferment faster.

The original gravity reading is around 1.042, this means depending on how well this ferments the final alcohol level will range from 5.5% to 8%. This may seem low but as I do more experiments I will build upon the best methods and increase this.

You may want to pour out some juice to avoid foam reaching the paper but for this experiment I'm leaving it full. The bottles come with around an inch of airspace, increasing this to two inches should lessen the chances of the paper getting wet. So far I changed out the paper a few times from bubbles splashing up but after a few days this wasn't an issue. I also swirled the bottles slightly to get rid of any foam build up in the first few days.

Red Star Premier Cuvee yeast (blue package) is excellent in that it ferments fast and creates little to no foam. It also flocculates (drops particles to the bottom) especially fast compared to other yeasts.

I have found that in the first few days a small cake of foam develops on the top of the juice as the yeast multiplies, I swirl the bottle a bit and this foam then dissipates back into the liquid. When the yeast starts to eat through the sugar the juice then just bubbles without much or any foam. I only added around 1/10 of a packet of yeast per bottle (around 1/8 tsp or less).

In my previous tests after dealing with stuck fermentations that still had residual sugar I came to the conclusion that the yeast needs oxygen in the first stages of brewing so I leave the top open with a paper towel covering it so there is some transfer of oxygen into the juice. Traditionally a bucket or larger type of container would be used for this first stage of fermentation which would have 1/3 of the container open to air even if a lid was on. This leads to a healthier fermentation and better chance of faster and complete fermentation.

For this experiment I used four bottles, I will list the ingredients below and the surprising results as they were a bit different that I expected.

Below is an estimation of the fermentation speed with a percentage in the first three days. After that the first three bottles started to catch up slightly but they had slightly larger bubbles and much less of them.

Juice + yeast (10% fermentation speed)
Juice + yeast + 1/8 tsp DAP (20% fermentation speed)
Juice + yeast + 1/8 tsp DAP + 1/16 tsp yeast nutrient (35% fermentation speed)
Juice + yeast + 1/8 tsp DAP + 1/16 tsp yeast nutrient + 1/8 tsp bentonite (100% fermentation speed)

These results surprised me in that I expected the Diammonium Phosphate and the B vitamin yeast nutrient to speed the fermentation mostly. The bentonite clay is added to clarify the wine faster by absorbing particles to its negative charge and dropping them to the bottom. For whatever reason the combination of ingredients with the bentonite drastically sped up the fermentation speed.

As it turned out I didn't have the exact size bung for this bottle so I just loosely put the cap on and covered it with a plastic bag and elastic band.

The picture below is day 6. Another unexpected result is that the one bottle with the bentonite is still cloudy. The other three have yeast and sediment collecting at the bottom of the bottles already.

After the airlock is added just leave the bottles for a few weeks until all bubbling has stopped. In my previous tests fermentation completed in as little as 12 days.

When bubbling has completely stopped refrigerate for a day or two, this is called cold crashing and helps drop out any remaining particles from suspension to the bottom of the bottle although the wine might be clear at this point already.

Then gently pour or siphon the wine into a sanitized clean bottle to avoid oxidizing the finished wine and leave the remaining yeast and sediment behind in the original bottle. Then it's basically ready! Just continue to refrigerate since no preservatives have been added. Cheers!

More information, test results and recipes will be added to my blog as I get enough resource credits to post. More pictures, hydrometer readings and final alcohol levels along with brewing times for each bottle will be added soon.

Please leave your thoughts and comments below!