Leave a bottle alone and it’ll get better on its own. Every wine the 
Fermentation Barrel makes is stamped with the day it was brewed, and from then on the effect can grow stronger and last longer as the world clock runs on. That 1:30 buff might reach 12:30 if you’re patient enough.
Nothing has to be done to make that happen. A bottle ages in a 
Chest, in your inventory or on a rack at exactly the same rate, as it’s only the passing days that get counted. 
Wine Racks are there for showing bottles off, and they do nothing at all to mature them.
3 of the wines are left out of it entirely. 
Chorus Wine, 
Creepers Crush and 
Mellohi Wine are applied instantly, so there’s no duration to stretch and no level to climb. The other 23 will all scale.
Getting Started
Aging isn’t something you obtain, it just starts on its own. Every bottle the Fermentation Barrel produces is stamped with the day it was brewed, and from that moment it’s aging whether you do anything or not.
Anything you didn’t brew yourself gets stamped as well. A bottle traded from the Wandering Winemaker, or pulled out of a chest, is dated the first time it ticks in your inventory, so it starts its life when you pick it up.
How the Age Is Counted
The age is the current world day minus the day the bottle was brewed. That world day is the total game time divided by 24,000, so the clock only advances while the world is loaded. A server that runs overnight will age your cellar far faster than a single-player world you only open at weekends.
A year is 24 in-game days by default, which works out at about 8 hours of play if a day takes 20 minutes. Anything without a stamp will be given one the first time it ticks in your inventory, so a bottle traded off the Wandering Winemaker starts its life when you pick it up, rather than whenever he made it.
The numbers behind all of this are copied onto the bottle when it’s stamped, and they aren’t read fresh each time. So a config change will only affect bottles brewed after you make it, and your existing stock keeps the calendar it was born with. That’s worth knowing before you edit anything mid-world.
Mechanics
Level and Duration
There’s 2 things that improve, and they run on separate clocks. The duration starts at 1:30 and gains 10 seconds every year, until it caps out at 12:30 after 66 years. The effect level climbs by 1 every 6 years and stops at V, which you’ll reach at 30 years.
Fresh
6 Years
18 Years
30 Years
You’ll get more out of the level than the duration on most wines. A fresh bottle is applied at base strength with no numeral on the tooltip at all, whereas one at V is sitting 5 steps above that. The duration can keep creeping up long after the level has stopped, so a very old bottle is mostly buying you time rather than power.
Reading the Tooltip
Hover a bottle and there’s 3 lines that’ll matter to you. The first gives the effect, its level as a Roman numeral and the duration in brackets, the second gives the age in years, and the third counts down the in-game days to your next step.
The Countdown Never Stops
That countdown never switches itself off. It keeps cycling every 144 days even after the level has capped at V, so a maxed bottle will still show days remaining, and then nothing happens when they run out. Check the level rather than the countdown when you want to know whether a bottle is finished.
Storage
Which Rack Takes What
None of the storage blocks change how fast a bottle ages. All they decide is how many you’re able to display at once. A plain 
Wine Rack holds 1 bottle of any size, whereas the 
Small and 
Big Wine Bottle Storage hold 4 and 9, but they’ll only take small ones.
| Block | Holds | Accepts |
|---|---|---|
| Wine Rack | 1 bottle | Any wine, small or large |
| Small Wine Bottle Storage | 4 bottles | Small bottles only (9 wines) |
| Big Wine Bottle Storage | 9 bottles | Small bottles only (9 wines) |
That small-bottle restriction might catch you out. 9 of the 26 wines are counted as small bottles, so 17 of them can only go on a plain Wine Rack, and 
Stal Wine is the awkward one. The tooltip on Stal Wine calls it a small bottle, and yet the storage blocks will refuse it, because the mod files list it in the large group instead.
You’ll find racks in 10 woods, from Acacia and Bamboo through to Dark Cherry and Spruce, and they all hold bottles in the same way. Pick whichever one matches the winery, as the choice is purely cosmetic.
Tips
Start a cellar in your first week. Age is counted from the brewed day, so the bottles you put away early are the only ones that’ll ever reach level V, and there’s no way to catch up later on.
Don’t build racks for the aging, build them because you want them. A chest matures a bottle at exactly the same rate, so racks are worth it for the look, and for keeping your vintages apart from everyday stock.
Watch the level rather than the countdown. The days-remaining line keeps cycling after the level has capped at V, so a bottle can look like it’s still improving when it’s actually finished.
Frequently Asked Questions
You don’t have to do anything at all. Every bottle is stamped with the day it was brewed and its age is worked out from the world clock, so it matures while it sits there.
A year is 24 in-game days by default. The effect level rises by 1 every 6 years up to V at 30 years, and the duration grows from 1:30 toward a 12:30 cap.
A chest is fine, and so is your own inventory. The age is the current world day minus the day the bottle was brewed, and nothing checks where it’s being kept.
Wine Racks and the Wine Bottle Storage blocks are there for showing bottles off. They age a bottle at exactly the same rate that a chest does.
Hold the bottle and right click the rack. A plain Wine Rack takes 1 bottle of any size, whereas the Small and Big Wine Bottle Storage hold 4 and 9.
Right click an occupied rack with an empty hand to take a bottle back out again. Racks come in 10 woods and all of them behave identically.
The 4 and 9 slot storages will only accept small bottles, and 17 of the 26 wines come in large ones. Those can only go on a plain Wine Rack, which holds a single bottle of either size.
Stal Wine is the one that catches people out. The tooltip on Stal Wine calls it a small bottle, and yet the storages refuse it, because the mod files list it in the large bottle group.
