Bulk Aging

Until recently, I have not bulk-aged my wines prior to bottling. Rather, I simply followed wine kit  instructions that tell you to wait for secondary fermentation to more-or-less come to an end, add finings, rack, and bottle. The whole process from opening the kit to bottling takes only a few weeks. There is no bulk aging.

After going through the "wine kit" process (without bulk aging) several times, I observe two main problems with wines made this way:

1.  Carbonation

Fermentation produces a lot of CO₂. Where does it go? CO₂ is dissolved in the wine until it reaches saturation. After that, CO₂ bubbles out of the wine into the air. When fermentation ends, there is still a lot of dissolved CO₂ in the wine, and it takes time to move into the gas phase. One way to release CO₂ is to agitate the wine (e.g. by stirring). Another way to get rid of it is to just give it time to gradually escape through the airlock.

If you don't give it time to escape before bottling, some of the CO₂ stays dissolved in the wine. All of my non-bulk-aged wines have a level of residual carbonation that detracts from the enjoyment. It's not much, but the carbonation is noticeable on the tongue. Who wants a tiny bit of fizz in their red wine?

Over the Christmas holidays, we opened up a bottle of a raspberry wine from a local winery. To our surprise, this wine contained more CO₂ than any of my homemade wines. The wine  released bubbles right there in the wine glass, just like sparkling wine. (And, no, it wasn't meant to be a sparkling wine!) The winery had probably bottled the wine before the CO₂ could escape. Fizzy fruit wine!

2.  Sedimentation

Finings do not remove 100% of the particulates from wine. Every time I used finings without bulk aging before bottling, a small amount of sediment has always appeared in the bottle. It usually takes a few months, but it's there and it spoils the appearance.

Sediment in rhubarb wine

An obvious way to prevent this from happening is to just let the wine age in a carboy (with an airlock) for a few months. By then, virtually 100% of the sediment should have crashed out in the carboy. By the time you bottle the wine, it should not be throwing any more sediment.

I have bulk-aged my most recent wines (two versions of Dragon Blood) and will write a separate post on them. Early observations are that the bulk aging solved the carbonation problem. I'm hopeful that there won't be any sedimentation in the bottles.

"Dragon Blood"

One of the best things I have done related to wine making is to join the Home Made Wine Making Google+ Community.  Community members are always posting interesting things and there is a lot of recipe sharing that goes on.  One of the wine recipes that frequently pops up is known as "Dragon Blood" - a name that was coined by a home made winemaker known as DangerDave.  DangerDave's Dragon Blood recipe is a variation of berry wine recipes that are described, for example, in that little purple "Winemaker's Recipe Handbook".  DangerDave's innovation is to use a frozen triple berry mix, found in the frozen food section of just about every supermarket, as the fruit.  By all accounts, Dragon Blood is easy to make and it can be ready to drink in less than two weeks.  This seemed like something worth trying.

As it happened, one day I was shopping at Costco, and spotted a frozen organic fruit mix (blackberry, blueberry, cherry, pomegranate, and strawberry).  This was just the thing to use in a first attempt of a Dragon Blood variation.  This frozen fruit sat in my deep freeze for a few months and I recently decided to get on with it.

"Super Fruit Blend"

As it is with chemistry experiments, so it is with wine making: The first thing you do is spend some time planning what you will do.  In wine making, this means reading and comparing different recipes, and then coming up with your own.  On looking at DangerDave's recipe, I was little nervous about how much lemon juice (48 oz.!!) is added because that is just too much acidity for me.  My purple handbook has a number of berry wine recipes that include only small amounts of acid blend, to improve the balance.  I decided to opt for that approach rather than load it up with lemon juice.

Here's the recipe:

3 gallons distilled water
15 cups granulated sugar
1 tsp peptic enzyme
2 tsp yeast nutrient
1.5 tsp acid blend (tartaric, citric, malic acids)
3 campden tablets (crushed)
1.5 kg of "Super Fruit Blend", in a nylon mesh bag (tied-off)

The sugar, peptic enzyme, yeast nutrient, acid blend, and campden tablets were dissolved in 3 gallons of water, in the primary fermenter (white plastic bucket with lid).  The frozen fruit, in a tied-off nylon mesh bag was steeped in the mixture for the next 24 hours.  During that period, I wrung out the bag a few times to squeeze out the juices and infuse the fruit with peptic enzyme.

Fruit in nylon mesh bag.

Ready to steep.

After steeping, and prior to adding the yeast, I took a density measurement so I could estimate alcohol content later.  Specific gravity = 1.087.  I added the yeast (1 packet of sparkling wine yeast) to get the fermentation started.

Primary fermentation underway.

During the primary fermentation, there were nice, mild, fruity aromas in the room.  Every other day, I stirred the mixture to help draw out the fruit flavours.  By the sixth day, the specific gravity was 1.035.  This was low enough that I siphoned the must into a carboy for secondary fermentation.

Secondary fermentation (4 days after transfer)

So there it is.  Fermentation is still going.  My plan is to let it go right to dryness before bottling.