Fifteen Pounds of Water, Twelve Ounces of Salt
A 15-pound turkey needs 340 grams of salt. Twelve ounces. Not twelve ounces for the bird, twelve for the water it sits in.
Fifteen pounds of water weighs 6,804 grams, and 5 percent of that is 340. The turkey only decides how much water you mix, because the bucket gets filled to roughly the bird’s own weight so it can go under.
Most brine problems start with that ratio getting swapped.
Fifteen pounds, 5 percent, 12 hours at 40°F or below. That is the whole recipe; the rest is arithmetic for other sizes, salts, and buckets.
Why the Percentage Goes Against the Water
Salt crosses from brine into meat until the two come closer to balanced, so the water is the reservoir and the reservoir sets the strength.
At one part water to one part bird, 5 percent of the water and 5 percent of the bird happen to be the same number of grams. That coincidence is why “5 percent of the meat” survives as folk wisdom, and why it breaks when somebody fills a cooler to the rim.
Salt and Time Are One Decision
Strength alone tells you nothing. A 10 percent brine for 90 minutes and a 3.5 percent brine for a day both work, and each is wrong on the other’s schedule.
| Strength | Window | Whole turkey |
|---|---|---|
| 3.5% (mild) | 12 to 24+ hours | The overnight soak |
| 5% (standard) | 4 to 12 hours | The default |
| 7% (strong) | 1 to 4 hours | A same-morning rescue |
| 10% (very strong) | 30 min to 2 hours | Not worth it on a whole bird |
The guide puts 3.5 percent at 12 to 24 hours and 5 percent at 4 to 12, while the turkey time guide allows 12 to 24. Twelve hours is where they overlap.
The Math for Any Bird on the Table
One part water to one part bird, 5 percent salt, sugar at half the weight of the salt.
| Bird | Brine at 1× weight | Salt at 5% | Sugar | Vessel |
|---|---|---|---|---|
| 10 lb | 5 qt (1¼ gal) | 227 g / 8 oz | 113 g | 12-qt stockpot |
| 12 lb | 6 qt (1½ gal) | 272 g / 9.6 oz | 136 g | 16-qt pot or 4-gal bucket |
| 15 lb | 7½ qt (1⅞ gal) | 340 g / 12 oz | 170 g | 5-gal bucket |
| 18 lb | 9 qt (2¼ gal) | 408 g / 14.4 oz | 204 g | 5-gal bucket, 2 in spare |
| 20 lb | 10 qt (2½ gal) | 454 g / 1 lb | 227 g | 5-gal bucket, near the rim |
| 22 lb | 11 qt (2¾ gal) | 499 g / 1.1 lb | 250 g | cooler, or two vessels |
That last row catches people. A 22-pound bird occupies 2.6 gallons, and 2.6 plus 2.75 exceeds a 5-gallon bucket. Move to a cooler, or split the soak between two birds, as our turkey timing post suggests.
A Cup of Salt Is Not a Cup of Salt
340 grams is the target. The volume it occupies depends on the crystal.
| Salt | Weight per tsp | 340 g is |
|---|---|---|
| Fine sea salt or table salt | 6 g | 57 tsp, about 1.2 cups |
| Morton coarse kosher | 4.8 g | 71 tsp, about 1.5 cups |
| Diamond Crystal kosher | 2.8 g | 121 tsp, about 2.5 cups |
That gap is why brining advice travels badly. “One cup per gallon” is 3.5 percent in Diamond Crystal and 7.7 percent in fine salt, at the 292 grams per cup on our conversion chart. One of those leaves a 15-pounder tasting like ham by morning.
Weigh the salt. A kitchen scale settles what no amount of recipe reading will.
A Bigger Bucket Needs More Salt
The water ratio slider is not decoration. Same 15-pound bird, same strength, four buckets.
| Water ratio | Water | Salt | Fits |
|---|---|---|---|
| 0.5× | 3¾ qt | 170 g | 8-qt pot, turn the bird at 6 hours |
| 1.0× | 7½ qt | 340 g | 5-gal bucket, comfortable |
| 1.5× | 11¼ qt | 510 g | 5-gal bucket, an inch left |
| 2.0× | 15 qt (3¾ gal) | 680 g | cooler only |
The failure is quiet. Fill a big cooler to the top, keep the 340 grams the internet gave you, and the soak runs at 2.5 percent for 20 hours. The bird comes out pale, and the recipe gets blamed.
Twelve Hours, Whatever the Bird Weighs
Brine time tracks thickness, not weight. Salt travels from skin to the middle of the thigh, and a 12-pound and a 22-pound bird are within an inch of each other on that route. Weight nearly doubles while distance barely moves.
Three things do move it:
- A partially frozen bird. Salt will not diffuse into ice. Thaw completely first, which runs 24 hours per 4 to 5 pounds in the fridge.
- A stronger brine. 7 percent gets there in 4 hours, and 10 percent in 90 minutes, at the cost of any margin for error.
- A longer soak than 24 hours. At 36 hours the outer half inch firms and tastes cured. Past 48 hours you are making something closer to deli meat than roast turkey.
Where the Bucket Actually Goes
A 5-gallon bucket stands 14½ inches tall. Most fridge shelves leave 10 to 12 inches, so measure before you commit.
- A 12-quart square container is 10½ inches tall and takes a 15-pound bird with 1.9 gallons of brine.
- A brining bag inside the roasting pan works on the bottom shelf and holds the weight without a bucket.
- A cooler is the answer when the fridge is full. Hold 35 to 38°F with frozen bottles and a thermometer in the liquid. A 45°F garage is not a refrigerator.
- Weigh the bird down. A 15-pounder floats. A dinner plate with a quart jar on it keeps the cavity submerged.
- Glass, food-grade plastic, or stainless steel. Not aluminum, and never a trash bag, whatever the internet says.
Read the Label Before You Buy Salt
Turn the bird over in the store. If the wrapper says basted, self-basting, or contains up to 3 percent solution, it is already brined, and a 5 percent soak on top of that is genuinely unpleasant. Kosher turkeys have been salted too, so halve the brine or skip it.
Two exclusions: never wet-brine a bird headed for the fryer, since water in the cavity and 350°F oil do not mix, and skip the bucket when a salt-heavy rub is planned.
Wednesday, for a Thursday Dinner
Work backward from the oven, not forward from the salt.
- Saturday. A 20-pounder moves to the fridge. Four to five days of thawing.
- Tuesday evening. Boil 2 quarts of water with the salt and sugar until clear, add the rest cold, and chill to 40°F. Warm brine plus a cold bird is how the danger zone gets a foothold. Bird in, weighted, lid on, fridge at 38°F.
- Wednesday morning. Twelve hours. Lift it out, pat it dry, and bin the towels. Skip the rinse, since USDA advises against washing raw poultry: the splash carries bacteria across the counter.
- Wednesday, all day. Back into the fridge uncovered on a rack over a sheet pan. A day of dry air is what makes wet-brined skin crisp at all.
- Thursday. Roast at 325°F and pull it at 165°F in the thigh, which the food safety temperature guide covers in full. The stuffing wants its own pan and its own clock.
That air-dry is the part people skip, and the reason a 12-hour soak beats a 24-hour one: the longer soak leaves no time to dry.
FAQ
How much salt for a 20-pound turkey?
454 grams, one pound, or about 1.5 cups of fine salt in 2½ gallons of water. Soak 12 hours, not overnight. For the full 24, drop to 3.5 percent and use 318 grams.
Can I brine a turkey in a cooler?
Yes, and it is the better option above 20 pounds. Hold 35 to 38°F with frozen bottles and a thermometer in the liquid, and check every 6 to 8 hours. Above 40°F, the clock stops being about flavor.
How long can a turkey stay in a 5% brine?
Twelve hours is the sweet spot and 24 is the ceiling. At 36 the texture turns firm and slightly cured. If the morning gets away from you, a bird at hour 14 is fine; at hour 30, roast it and expect a firmer, saltier slice, not a ruined one.
Try Our Free Tools
The Brine Calculator sizes salt, sugar, and water for any bird and any water ratio. The Holiday Meal Planner turns your guest count into a turkey weight, thaw days, and a roast estimate before you buy anything. The Cooking Time Calculator converts that roast for a convection oven.
Sources
The 5 percent standard, the strength scale, and the 12-to-24-hour window come from the Brine Calculator. The 40°F holding limit, the 165°F finished temperature, the thaw rate, and the labeling rules for enhanced poultry come from USDA FSIS guidance. Salt and sugar weights per cup come from our conversion chart.
Five percent of the water’s weight, twelve hours, one night uncovered in the fridge. The exception is the bird that arrives pre-basted, which needs no bucket at all and will only suffer from one.