Empty hopper overnight: how long a full hopper lasts

How long a full hopper lasts overnight

Short answer: it depends on the grill, the set point, and the weather more than on the meat. On a Traeger Pro 575 (an 18 lb hopper, about 0.9 lb/hr at 225 F in our estimate), a full hopper runs about 19 hr 37 min at 225 F in mild weather. In winter it runs about 9 hr 20 min at 225 F and 7 hr 20 min at 275 F. In winter that is less than a full night. A 30 lb hopper like the Pit Boss Navigator 850 runs about 14 hr 7 min at 225 F and 11 hr 6 min at 275 F in winter. These are model numbers, not measurements. See the table below for more grills.

• Fill it to the top right before bed. A hopper that is "pretty full" has already given back hours. Our hours assume a full one, minus a 0.35 lb startup pad.
• Time the refill, not the alarm. If the cook is longer than the hopper run time, refill about 30 minutes before the hopper is due to run dry, which is what the start time planner does. If you would rather sleep once, top it off at the halfway point. The worked example below shows what that looks like.
• Hopper size beats set point. Going from 225 F to 275 F shortens the cook, but it also burns faster, so a full hopper runs 2 hr less in winter on the Pro 575. A bigger hopper is the only change that moves the answer much. Compare hopper sizes in the grill database.
• Bag size. An 8 lb pork butt at 225 F in winter wants about 22.5 lb, which is 2 bags of 20 lb or 1 bag of 40 lb. Open the second bag before you go to sleep, not after the fire dies. How many pounds of pellets has the bag math for other cooks.
• Winter changes everything. Our winter setting is a 2.1x burn multiplier, which cuts hopper hours roughly in half. See cold-weather burn.

Food safety is why this matters. USDA says bacteria grow most rapidly between 40 and 140 F, doubling in as little as 20 minutes, and to keep hot food at or above 140 F (USDA FSIS, Danger Zone (40 F to 140 F)). USDA also says to keep the smoker air between 225 and 300 F throughout the cook (USDA FSIS, Smoking Meat and Poultry). A dead fire is not only a ruined brisket. If you wake up to a cold grill, check the meat with a thermometer, and read the section on a dead fire at the end of this page.

Hours until the hopper is empty, by grill

Model output, not a measurement. Each cell is how long a full hopper runs from the moment the meat goes on, with the burn rate in lb/hr underneath. Burn starts from each grill's assumed rate at 225 F, then scales with set point and weather, the same way the calculator does. Click a cell to open it there. The assumed burn rates are our estimates, labeled as such in the grill database.

Read it against the length of your cook. A 12 lb packer is about 13 hr 55 min to 16 hr 30 min in the model at 275 to 225 F, and an 8 lb pork butt is about 11 hr 42 min. The brisket numbers are on the stall guide, and the pork butt example is below. Mild means about 60 to 80 F. Wind, a leaky lid, and wet pellets are not in the math, and they only shorten these hours.

Worked example: a 12 hour overnight pork butt

Take an 8 lb pork butt at 225 F on a Traeger Pro 575. The model puts the cook at 11 hr 42 min, so call it a 12 hour overnight cook. Say the meat goes on at 9:00 PM. Every number below is calculator output, labeled model, not a source. The same cook in mild weather and in winter:

In mild weather the hopper covers the cook with about 12.7 lb to spare, so a full hopper at bedtime is enough on paper. In winter it is not. The same cook wants 22.5 lb from an 18 lb hopper, and the hopper runs dry about 2 hr 22 min before the cook ends.

Refilling at the halfway point. In winter the halfway mark is 2:51 AM the next day. The hopper still has about 6.6 lb (37%), so topping it off to full adds about 11.4 lb, about 57% of a 20 lb bag. The second half burns about 11.1 lb, so you finish with about 6.9 lb left. That is one trip outside, with room for a windy night. The other option is waiting until 5:50 AM the next day, 30 minutes before the hopper would go empty. It works on paper, but there is no margin if the wind picks up. A refill at the halfway point trades an earlier alarm for a safer morning. Put your own grill and serve time into the smoking start time planner for the exact clock times.

The same pattern holds for brisket. A packer is longer than this butt, so the hopper problem starts earlier and the stall can stretch the cook further. See the brisket stall guide before you trust a clock.

Overnight brisket is a hopper problem dressed up as a meat problem. An 18 lb hopper looks huge on a Saturday afternoon. It looks small at 3 a.m. when the grill has been holding 225 F in the wind for ten hours.

Large barrels make it worse. More steel and more leaks mean more pellets for the same set point. That is why a Traeger Pro 780 and a Pro 575 can share an 18 lb hopper and not share the same overnight odds.

Use the warning, then ignore pride

The calculator flags three bad cases: the cook needs more pellets than the hopper holds, the margin at the end is thin on a cook of 8 hours or longer, and the margin is thin on a shorter cook. Thin means under 4 lb left, or under 15% of the hopper. It also shows how many hours a full hopper actually runs, so you can see how far short you land. Those rules are conservative on a calm night and optimistic in a storm.

Try a 14 lb brisket on a Pro 575 hopper in winter. The hopper runs dry hours before the brisket is done. Swap in the RT-700 (legacy / discontinued), a 40 lb hopper on a lower burn assumption, and the warning clears. Swap in the DualFire 1200 instead, a 70 lb hopper on a higher burn assumption, and it clears with far more left over. The RT-700 gets there on a lower burn, the DualFire on sheer tank size. A bigger hopper is not the answer by itself. Hopper size minus startup, divided by burn rate, is.

Practical refill habits

Fill the hopper before you go to sleep, not when it looks "pretty full."

Want the actual clock time? The smoking start time planner takes your serve time and grill and gives you the hour the hopper should run dry and when to refill it.

Leave a second bag where you will actually walk at midnight. Not on a high shelf.

If you refuse to get out of bed, you need more hopper or a shorter cook, not a nicer app. Compare listed hopper sizes in the grill database.

A full bag in the garage is not the same as a full hopper. How long a full hopper of pellets lasts is the hopper-hours version. How long a bag of pellets lasts has the bag-hours version, including what winter does to it. Pork butts hit the same overnight math: pellets for pork shoulder.

If the fire went out overnight

Check the meat with a thermometer before you decide anything. USDA says to keep hot food at or above 140 F, that bacteria grow most rapidly between 40 and 140 F, and to never leave food out of refrigeration over 2 hours (USDA FSIS, Danger Zone (40 F to 140 F)). USDA does not publish a rule written for a pellet grill that went cold mid-cook, and PelletDeck is not food-safety advice. If you cannot tell how long the meat sat below 140 F, use USDA's general rule above, and the USDA Meat and Poultry Hotline at 1-888-674-6854 can answer your case. The food-safety disclaimer has the USDA minimum internal temperatures.