Barrel Aging Process

updated 09/12/2023

A question was recently posted on WineMakingTalk, asking about the process folks use for their barrels. I wrote a reply, which formed the basis for this post. Following is my general process:

1. Crush & ferment in October.
2. Post-fermentation, let the wine settle in glass carboys/demijohns for 2 to 3 weeks.
3. In November, rack into neutral barrels.
4. Prior to each monthly topup, gently stir the wine for the first 9 months, e.g., bâtonnage.
5. Three months prior to bottling, stop stirring to let the fine lees settle.
6. Bottle the following November when the new wine is ready for barrel.

Please note this is a work-in-process, and it’s likely I’ll alter things with more experience.

Following are notes that expand upon each of the above steps.

1. Crush & ferment in October

I’m on the east coast USA so I get a single shipment of grapes from the west coast (California), which means all batches are made simultaneously.

2. Post-fermentation, let the wine settle in glass carboys/demijohns for 2 to 3 weeks

Gross lees supposedly precipitates within 24 to 72 hours of the end of fermentation. After pressing I allow a few weeks in glass during which the gross lees (fruit solids) precipitates as does most of the fine lees (yeast hulls). At bottling time (12 months later), I have less than 1″ (2.5cm) sludge in the bottom curve of 54 liter (14.25 US gallon) barrels.

3. In November, rack into neutral barrels

For a batch, I rack all containers into a single 32 gallon (121 liter) Rubbermaid Brute to homogenize the wine. This ensures the wine is uniform, so when I topup the barrel during the year, the wine going in is the same as what’s already in barrel. If the wine is not homogeneous, topping the barrel can change the flavor, which may make it more difficult to judge how the wine is progressing.

Note that I make 16 to 20 US gallon (60 to 76 liter) batches, so homogenizing in a Brute works for me.

At this time I gently stir the wine to encourage CO2 to escape, a process the racking starts. Then I fill a barrel, and any remaining wine goes into smaller containers. Note that at this scale, a 19 liter carboy is a smaller container, although typically I use 4 liter jugs.

4. Prior to each monthly topup, gently stir the wine for the first 6 months, e.g., bâtonnage

Note: I have some sediment in the bottle of recent bottlings, so 3 months of non-stirring is not enough. I currently stop stirring the barrel 6 months before bottling.

Barrels evaporate through the wood, so I add ~ 750 ml wine per barrel each month. Over a 12 month period, for my barrels the angel’s share (a term borrowed from the Bourbon industry) is about 10% of the volume.

Wine has no convection currents and I have neutral barrels (all oak character is used up), so I add oak cubes. The oak flavoring does not spread much within the wine, so stirring at topup for at least 3 months provides me with a more accurate assessment during the monthly tasting.

Anyone not tasting their barrels at topup is missing a golden opportunity in self-education. It’s useful to experience how the wine changes.

5. Six months prior to bottling, stop stirring to let the fine lees settle

I currently allow 6 months for the wine to settle, so the last stir is in May for a November bottling. So far haven’t had sediment in the bottle. If I do, I’ll consider it a lesson learned and stop stirring the wine sooner.

If I made 2 barrels of the same wine, I’d consider racking one in February/March to see if removal of the sediment makes any difference in the final wine.

6. Bottle the following November when the new wine is ready for barrel

At this time I bottle 13 months after crush, as it fits the cycle of the barrel so I don’t need a holding solution. Barrels must be kept full else they dry out and leak, and/or grow mold. One choice is to fill the barrel with a holding solution (water + K-meta + acid), whereas I simply choose to keep the barrels full.

At bottling time, I rack the wine from the barrel into a Brute, and add any remaining topup wine. I add K-meta and glycerin, then bottle.

I never bottle from the barrel to avoid sucking up any sediment, which ruins the appearance in the bottle. I rack all but 2 to 4 bottle’s worth of wine. After bottling the main portion, I carefully rack the remaining wine and bottle it separately. This is usually clear, but I use it first and never give away these bottles, in case sediment was sucked up.

The loose sludge in the barrel gets poured into a 1.5 liter bottle and refrigerated for a week. I’ve been netting 1 additional bottle from that, which is used immediately.

It’s likely I’ll tweak my process with time and experience, but don’t expect the overall flow to change much.