Learning how to wash your gi correctly is one of the most important habits any martial artist can develop. Whether you train judo, Brazilian jiu-jitsu, or both, your gi takes a beating every session — absorbing sweat, bacteria, and mat grime. Wash it wrong and you risk shrinking it by a full size, damaging the weave, or shortening its lifespan significantly. This guide covers everything Canadian judo and BJJ athletes need to know about gi care, including a few considerations specific to training here in Canada.
Why Proper Gi Care Matters
A good gi is an investment. Whether you train in a judo gi or a BJJ gi, quality uniforms are built to last years — but only with proper maintenance. Neglecting gi hygiene leads to permanent odours caused by bacteria embedding in the cotton fibres, as well as fabric breakdown from repeated exposure to sweat acids. Beyond hygiene, improper washing is the number one cause of gi shrinkage, which can take a perfectly fitted A3 down to an A2 after just one hot wash.
The Golden Rules of Washing Your Gi in Canada
1. Wash After Every Single Session
This is non-negotiable. Leaving a sweaty gi in your bag overnight — or even for a few hours — lets bacteria multiply rapidly. The longer you wait, the harder it is to remove odours completely. Get into the habit of tossing your gi in the wash as soon as you get home from training, especially during Canadian summers when heat accelerates bacterial growth, or during winter months when wet gear stuffed in a hockey bag can develop mildew quickly.
2. Use Cold Water — Maximum 30°C
Cold water is the most important setting you can control. Most Canadian washing machines label this as "Cold" or list it around 20–30°C. Hot water causes cotton fibres to contract dramatically; a single hot wash can shrink a gi by 5–10%, which translates to jumping a full size. Set your machine to cold or delicate warm (30°C maximum) and keep it there every single time.
If you need to shrink an oversized gi intentionally — for example, a new single-weave judogi that runs large — wash it in warm water (40°C) and air dry indoors. This gives controlled, moderate shrinkage without the extreme results of a dryer cycle.
3. Turn Your Gi Inside Out
Before placing your gi in the machine, flip it inside out. This protects embroidery, patches, and the outer surface of the weave from abrasion against the drum, while directing detergent contact to the inner surface where sweat and oils accumulate most. For white gis especially, this also helps preserve colour uniformity over time.
4. Use a Gentle Cycle With Mild Detergent
A gentle or delicate cycle reduces mechanical stress on the weave. Use a mild, unscented detergent — roughly half the amount you would use for a regular load. Avoid fabric softeners entirely: they coat cotton fibres with a residue that traps bacteria and odour rather than eliminating them. Softeners also gradually break down the structural integrity of the weave, making your gi feel limp and worn before its time.
Hard water is common in many parts of Canada, particularly in Ontario, Alberta, and British Columbia. If you live in a hard water area, a small amount of white vinegar (roughly 60 mL) added to the rinse cycle acts as a natural softener and helps neutralise bacterial odours without damaging the fabric.
5. Never Use Bleach
Even on white gis, bleach is off the table. Chlorine bleach weakens cotton fibres rapidly and causes yellowing over time. If you need to brighten a white gi, use an oxygen-based whitener (such as OxiClean), which lifts stains without the fibre damage. Dissolve it in cold water and soak the gi for 30 minutes before washing as normal.
How to Dry Your Gi Without Shrinking It
The drying stage is where most gi shrinkage actually happens. Machine dryers run at 50–70°C — well above the threshold that causes cotton to contract significantly. One tumble dry cycle can shrink a gi as much as a size and a half and permanently distort the collar and lapels.
Always air dry your gi. Hang it on a sturdy hanger or a drying rack in a well-ventilated area. In Canada, this means indoors for most of the year: the cold, dry air of a Canadian winter will not dry your gi efficiently outside, and freezing temperatures can make cotton brittle. During summer months, indirect outdoor drying works well, but avoid direct sunlight for extended periods — UV rays bleach coloured gis and can weaken the outer cotton layer over time.
Dry your gi as promptly as possible after washing. Do not leave it rolled up in the machine once the cycle finishes — this creates the exact warm, damp, dark environment that mildew needs to take hold.
Dealing With Common Gi Problems
Persistent Odour
If your gi smells even after washing, bacteria have embedded deeply in the fibres. Soak the gi in a solution of cold water and white vinegar (1 part vinegar to 4 parts water) for one to two hours before washing. For severe cases, an oxygen soak overnight will usually eliminate the odour completely. Avoid masking odours with fabric sprays — they do not kill bacteria and leave a residue that attracts more.
Stains From Training
Address stains immediately — dried stains are significantly harder to remove. For blood, rinse immediately in cold water only (hot water sets blood stains permanently), then treat with hydrogen peroxide on white gis or a cold-water enzyme-based stain remover on coloured gis. For mat grime and general discolouration, a pre-soak with oxygen cleaner before your regular wash cycle works well.
Gi Shrinkage After Washing
If your gi has already shrunk, it is possible to partially restore its size. Soak it in lukewarm water with a small amount of hair conditioner for 15–20 minutes, then gently stretch it while damp and lay it flat to dry. This works best on light shrinkage; a gi that has been machine dried repeatedly is unlikely to recover fully.
Judo Gi vs BJJ Gi: Any Differences in Care?
The care principles are essentially the same, but weave types differ. Traditional judo gis are made from single or double weave cotton — heavier, thicker fabric that takes longer to dry and requires more care to avoid shrinkage. IJF-approved double weave judogi in particular should be treated with extra caution: cold water only, air dry always.
BJJ gis come in a wider range of weaves: pearl weave, gold weave, and ripstop are common. Pearl weave and ripstop contain synthetic fibres (usually polyester) that make them more resistant to shrinkage than pure cotton, but the same cold water and air dry rules still apply to protect the cotton components and preserve the gi's pre-shrunk size.
How Often Should You Replace Your Gi?
With proper care, a quality gi should last two to five years of regular training. Signs it is time for a replacement: the collar is thinning and fraying, seam stitching is pulling apart at the knees or armholes, the fabric has thinned to the point of becoming translucent, or patches are peeling. If you compete, inspect your gi before events — a torn seam mid-roll can mean disqualification.
Ready for a New Gi? Shop Canadian.
When your gi has reached the end of its life, or when you are ready to add a second gi to your rotation (highly recommended — alternating between two gis extends the life of both and ensures you always have a clean one ready), Matsuru Canada has you covered. We ship from our Canadian warehouse with no cross-border duties, and all pricing is in CAD.
Whether you train twice a week at a local club in Quebec City or five days a week at a competitive academy in Vancouver, your gi will perform better and last longer when you treat it right. Cold water, air dry, wash after every session — stick to those three rules and your gi will be ready to train as hard as you do.