Racking Wine: When, Why, and How to Transfer Wine

What Is Racking?

Racking is the process of transferring wine from one vessel to another, leaving behind the sediment (called lees) that has settled to the bottom. It is one of the most fundamental techniques in winemaking and one that every home winemaker will perform multiple times during the production of a single batch of wine.

The term comes from the French word soutirage, and it has been practiced since the earliest days of winemaking. Before modern filtration and fining agents existed, racking was the primary method for clarifying wine and separating it from the byproducts of fermentation.

At its simplest, racking involves nothing more than carefully moving clear wine off the top of a sediment layer. But doing it well, at the right times and with proper technique, has a significant impact on the clarity, stability, and flavor of your finished wine.

Why Racking Is Essential

Sediment in wine comes from several sources: dead yeast cells, grape solids, precipitated tannins, and protein-tannin complexes. While short-term contact with fine lees can benefit certain wine styles (see sur lie aging and batonnage), prolonged contact with gross lees introduces serious risks:

• Off-flavors: Decomposing yeast cells can produce hydrogen sulfide (H2S), which smells like rotten eggs, and mercaptans, which smell like burnt rubber or garlic
• Microbial spoilage: Sediment provides a nutrient-rich environment where unwanted bacteria like Brettanomyces and Acetobacter can thrive
• Haze: Proteins and other compounds in the lees can keep wine permanently cloudy if not removed
• Bitterness: Prolonged contact with spent grape solids can extract harsh, bitter compounds into the wine

Racking removes these risks by physically separating the clean wine from the problematic sediment.

Equipment You Will Need

Siphoning Equipment

The auto-siphon is the single most important piece of racking equipment for home winemakers. This device uses a pump mechanism to start the siphon flow without the need to suck on the tubing (which introduces bacteria) or create complicated gravity setups.

• Auto-siphon: A 3/8-inch diameter auto-siphon is standard for 5-6 gallon batches. Choose a model with a sediment tip (a curved end piece that keeps the intake above the lees layer). Cost: $12-18
• Siphon tubing: Clear, food-grade vinyl tubing that connects to the auto-siphon. Buy at least 6 feet to allow comfortable working distance between vessels. Cost: $3-5
• Tubing clamp: A simple pinch clamp that lets you stop and start flow without removing the siphon. Essential for controlling the transfer. Cost: $2-3
• Racking cane: An alternative to the auto-siphon, this rigid tube with a curved tip is inserted into the wine. Requires a separate method to start the siphon. Cost: $5-8

Receiving Vessels

You need a clean, sanitized vessel to receive the racked wine:

• Glass carboy: The most common choice. Have at least two carboys so you always have a clean one ready to receive wine
• Food-grade plastic bucket: Acceptable for short-term holding during racking, but transfer to glass or stainless steel promptly
• Stainless steel variable-capacity tank: Ideal because the floating lid eliminates headspace concerns

Sanitation Supplies

• No-rinse sanitizer (Star San or equivalent)
• Spray bottle filled with sanitizer solution
• Clean towels

When to Rack Your Wine

First Racking: Off the Gross Lees

The first racking is the most important. Perform it 5-7 days after primary fermentation begins, or when the vigorous bubbling in the airlock has slowed to about one bubble every 30 seconds. At this point, the hydrometer should read approximately 1.010-1.020 specific gravity.

The gross lees at the bottom of the primary fermenter consist of heavy yeast sediment, grape solids, and other debris from the crush. This material decomposes quickly and is the most likely source of off-flavors. Getting the wine off the gross lees promptly is critical.

For red wines that have been fermenting on the skins, the first racking coincides with pressing: separating the wine from the grape skins and seeds, then transferring the pressed wine to a secondary vessel.

Second Racking: After Fermentation Completes

The second racking occurs 2-4 weeks after the first, once fermentation is fully complete. Check with a hydrometer: the specific gravity should be stable at 0.995 or below on two consecutive readings taken 48 hours apart.

By this point, a new layer of fine lees has settled. This racking moves the wine to a clean vessel for the beginning of the aging and clarification phase.

Third Racking: During Aging

A third racking is performed 6-8 weeks after the second, or whenever a visible sediment layer of 1/4 inch or more accumulates at the bottom of the vessel. This racking further clarifies the wine and removes any additional precipitated material.

Additional Rackings

Continue racking every 6-8 weeks as needed during aging, whenever significant sediment accumulates. Most wines require 3-4 total rackings over 3-6 months before they are clear enough for bottling. Some wines, particularly heavy reds and fruit wines, may require 5-6 rackings.

When to Rack for Malolactic Fermentation

If you are inoculating for malolactic fermentation (MLF), rack the wine off the gross lees first, then add the MLF culture to the clean wine in the secondary vessel. Do not rack again until MLF is complete, as racking during MLF can disrupt the bacterial culture.

Step-by-Step Racking Procedure

Step 1: Prepare Your Work Area

Set up your racking station with the source vessel elevated above the receiving vessel. A table or countertop for the source vessel and the floor for the receiving vessel works well. You need at least 18-24 inches of height difference for reliable siphon flow.

Ensure the source vessel has been undisturbed for at least 24 hours before racking so the sediment is fully settled.

Step 2: Sanitize Everything

Sanitize all equipment that will contact the wine:

1. Prepare a fresh batch of Star San per package directions
2. Run sanitizer solution through the auto-siphon and tubing by pumping sanitizer through the entire assembly
3. Sanitize the receiving vessel by swirling sanitizer inside and draining
4. Spray the outside of the source vessel opening with sanitizer
5. Sanitize the airlock, bung, and any other fittings you will use on the receiving vessel

Step 3: Position the Siphon

Carefully remove the airlock from the source vessel. Insert the auto-siphon slowly into the wine, positioning the intake tip about 1 inch above the sediment layer. Angle the tip slightly upward if using a sediment tip.

Critical technique: Lower the siphon into the wine slowly and smoothly. Jabbing it in quickly will disturb the sediment and defeat the purpose of racking.

Step 4: Start the Siphon

With the tubing end in the receiving vessel, give the auto-siphon one or two smooth pumps to start the flow. Wine should begin flowing through the tubing into the receiving vessel. Once flow is established, do not pump again because the siphon will sustain itself by gravity.

If using a racking cane instead of an auto-siphon, you can start the siphon by filling the tubing with sanitizer, clamping the end, attaching it to the racking cane, submerging the cane, and then releasing the clamp over the receiving vessel. The sanitizer flowing out creates the suction to start the wine flowing.

Step 5: Monitor the Transfer

Watch the wine flowing through the clear tubing. It should be relatively clear, with no visible chunks of sediment being pulled through. As the wine level drops in the source vessel, you may need to tilt the vessel gently to pool the remaining clear wine near the siphon intake.

The critical decision point: As you near the bottom of the source vessel, you will see the wine near the intake becoming cloudy as the siphon begins pulling from near the lees layer. Stop the transfer before significant sediment enters the tubing. It is better to lose a small amount of clear wine than to transfer sediment into the receiving vessel.

Expect to leave behind 1/2 to 1 cup of wine with the sediment in a 5-6 gallon batch. This small loss is normal and acceptable.

Step 6: Seal the Receiving Vessel

Once the transfer is complete:

1. Remove the siphon tubing from the receiving vessel
2. Check the fill level. The wine should be within 1-2 inches of the bottom of the vessel neck to minimize headspace
3. If there is excessive headspace, top up with a similar wine, or use glass marbles to displace the air
4. Fit a sanitized airlock and bung immediately
5. Add sulfite if needed (typically 1/4 teaspoon of potassium metabisulfite per 6 gallons at each racking)

Step 7: Clean Up

Dispose of the lees from the source vessel. Rinse and clean all equipment immediately. Dried lees are extremely difficult to remove from glass carboys. A carboy brush and hot water make cleaning much easier when done promptly.

Common Racking Mistakes

Disturbing the Sediment

The single most common mistake is being too aggressive when inserting or moving the siphon, stirring up the very sediment you are trying to leave behind. Always move the siphon slowly and deliberately. If the sediment gets disturbed, stop and wait 24 hours for it to resettle before trying again.

Not Sanitizing Properly

Every racking is an opportunity for contamination. Shortcutting the sanitation process is a gamble that eventually results in spoiled wine. Take the five minutes required to sanitize everything properly. Every single time.

Racking Too Infrequently

Leaving wine on heavy sediment for too long is the primary cause of hydrogen sulfide problems in home wine. If you smell rotten eggs, rack immediately and consider adding a small dose of sulfite.

Racking Too Frequently

Conversely, excessive racking introduces oxygen at each transfer, which can lead to premature oxidation. Each racking should have a clear purpose: removing sediment, adding sulfite, or preparing for the next winemaking step. Do not rack just because a certain amount of time has passed if there is no significant sediment to remove.

Excessive Splashing

Splashing wine during transfer introduces large amounts of oxygen. Keep the tubing end submerged in the wine in the receiving vessel at all times during the transfer. The wine should flow in smoothly beneath the surface, not cascade from above.

Tips for Better Racking

• Use gravity, not force: A slow, steady siphon flow transfers wine more gently than a fast flow. Elevation difference controls flow speed
• Rack in a cool environment: Cooler temperatures mean less dissolved oxygen uptake during the transfer
• Pre-purge with CO2: If you have access to food-grade CO2, purge the receiving vessel with CO2 before racking to displace oxygen. This is the single best step you can take to minimize oxidation during racking
• Keep records: Note the date, the amount of sediment left behind, and any observations about wine clarity and aroma at each racking. This log helps you track your wine's development and identify problems early
• Top up after racking: Always ensure minimal headspace in the receiving vessel. Oxygen is the enemy of aging wine

Frequently Asked Questions

How many times should I rack my wine?

Most wines benefit from 3-4 rackings over the course of 3-6 months between the end of fermentation and bottling. Rack whenever a visible sediment layer of 1/4 inch or more accumulates. Some wines, particularly those with heavy sediment loads like fruit wines, may require additional rackings.

Can I rack too often?

Yes. Each racking introduces a small amount of oxygen. Excessive racking, particularly without adding sulfite, can lead to premature oxidation, which manifests as browning, loss of fresh fruit character, and a flat, stale taste. Rack only when there is meaningful sediment to remove.

What is the difference between gross lees and fine lees?

Gross lees are the heavy sediment that settles within the first 48-72 hours after fermentation. They consist of large particles: yeast clumps, grape solids, and other debris. They decompose quickly and should be removed promptly. Fine lees are the much smaller particles that settle over the following weeks and months. Fine lees decompose slowly and can actually benefit the wine through autolysis (see batonnage and sur lie aging).

Do I need to add sulfite every time I rack?

It is good practice to add a small dose of potassium metabisulfite at each racking to maintain adequate free SO2 levels. Racking introduces oxygen, which consumes sulfite, so replenishing after each transfer helps protect the wine. A standard addition is 1/4 teaspoon per 5-6 gallons, which adds approximately 25-30 ppm of SO2.

What if I accidentally transferred some sediment?

Do not panic. A small amount of sediment transferred during racking will simply settle to the bottom of the new vessel and can be removed at the next racking. If you accidentally transferred a large amount, allow the sediment to settle for 24-48 hours and rack again promptly to minimize the time the wine spends on the disturbed lees.