Keg Levels on the Board: Set Your Low Mark

To show keg levels on a beer menu before a beer kicks, set a low mark for each tap in pours left: busiest-hour pours times warning minutes, divided by 60. Then decide line by line whether guests see it.

The sections below cover why 1 mark for the whole wall misfires, a worksheet with a worked example, when a low note belongs on the guest board, how to word it, and how TapDisplay tracks levels.

What is a low keg mark for?

A low keg mark is a trigger for work that has to happen before the keg kicks. When a keg crosses its mark, someone stages the backup, writes the next beer's line, or tells the floor. The mark sets how early that warning arrives.

Without a mark, "low" means whatever each bartender thinks it means. One says there's plenty left, another says it's nearly gone, and nobody has a number to check against.

Reading the keg itself is a separate job. Game night keg prep walks through weighing what's left in each keg the day before a big night. Once you can read a level, the mark tells you what to do with it.

Why doesn't a single low mark work for the whole wall?

A single mark for every tap, such as "low at a quarter," fails because kegs come in different sizes and lines need different amounts of warning. A quarter of a big keg and a quarter of a small one are very different amounts of beer.

Federal rules define a barrel of beer as 31 US gallons, as the text of 27 CFR 25.11 on Cornell's Legal Information Institute shows. The Brewers Association's Draught Beer Quality Manual lists the common keg sizes: a half barrel holds 15.5 gallons (1,984 fluid ounces), a quarter barrel 7.75 gallons (992 fluid ounces), and a sixth barrel 5.16 gallons (660 fluid ounces).

Here is what "a quarter left" means in each, counted in 16 oz pours before foam and waste:

The same "quarter" mark gives you about 3 times as many pours of warning on a half barrel as on a sixth barrel. If both go low at the same point, the big keg warns too early and the small one too late.

The beer behind the line matters too. A fast lager with a cold keg of the same beer waiting needs a short warning. A one-off barleywine with nothing behind it needs a longer one, because more has to happen before it runs out. So set the mark per tap, and count it in pours.

How do you set the low mark for each tap?

Set each tap's mark from 4 answers, then run 1 formula. Answer these for every line:

1. What's behind it? The same beer, cold and ready. A different beer on deck. Or nothing.
2. What has to happen before it kicks? Write down the actual jobs, like "stage the backup" or "write the next line." "Be ready" isn't a job.
3. How many minutes do those jobs take on a busy night?
4. How often does someone check levels? If levels get checked at pre-shift and then only when someone remembers, your check gap is the whole shift.

Add the minutes from questions 3 and 4 to get the warning time. Then:

Low mark (pours left) = busiest-hour pours x warning minutes / 60, rounded up

Busiest-hour pours is your own count. Have the bartender on that well tally the line through the busiest hour of a busy night. Count a 10 oz pour the same as a 16 oz pour; doing that only moves the warning earlier.

Check that a "cold" backup really is cold. The Brewers Association manual says every keg must be at or below 38°F when served, and its chill table gives a keg at 44°F, which can still feel cold to the hand, 18 hours to reach 38°F. If the backup came in on today's delivery, plan that line as if nothing is behind it.

What does a filled-in worksheet look like?

Here is the worksheet filled in for 3 lines of a 12 tap taproom. The beers are generic, and the minutes, pour counts and prices are made up, so use your own.

Taps 1 and 6 land on the same number for different reasons. Tap 6 sells slower, but it has more to do before the kick.

Tap 12 pours 8 oz, so convert before you write the mark down. 6 pours x 8 oz = 48 oz, which is 3 pints of 16 oz. Write each mark in the unit your staff actually read.

If you track levels as a share of the keg, divide the ounces left by the keg's full size. Tap 1's 20 pours are 320 oz, which is 16% of a 1,984 oz half barrel. Tap 12's 48 oz is 7% of a 660 oz sixth barrel. On a 0 to 100 scale, tap 1 goes low at 16 and tap 12 at 7.

A blank row to copy onto your tap sheet:

Tap | Beer and keg | Behind it | Jobs | Ready | Check gap | Warning | Busy-hour pours | Low mark
____|______________|___________|______|_______|___________|_________|_________________|_________

Write the marks on the tap sheet at the board station, next to each line. When a keg crosses its mark, mark it, every time. Redo the sheet when a line changes beers or your busy nights change.

Should guests see that a keg is low?

Guests should see a low note only on lines where they lose something by waiting, which usually means nothing of that beer sits behind the line. Set it line by line as a house rule.

A low note can nudge a guest to order now. It can also promise a loss that never comes, and a "last pours" note on a line that kicked an hour ago is worse than no note. If kicked lines don't get fixed fast on your busy nights, keep low notes off the guest board until they do. What to do when a keg kicks mid-shift covers that fix.

Watch the count, too. If 3 lines carry notes at once, none of them stand out.

When a different beer is on deck, an on deck section can carry the message instead. Listing the next beer there tells guests what's coming to that tap.

How should a low keg read on the board?

A low note should be short, true and worded the same way every time. Put it at the end of the line, after the price, so the beer name doesn't move.

12 | Barleywine | 10.5% | 8 oz $9 | Last keg
12 | Barleywine | 10.5% | 8 oz $9 | Last few pours

"Last keg" can go up the day you tap it, since it's true from the first pour. "Last few pours" goes up when the keg crosses its mark and comes off when it kicks.

Keep these off the guest board:

• "Low." At the end of a line it can read as low ABV or low calorie.
• "Almost kicked." That's bar talk, and plenty of guests don't know what kicked means.
• A pour count, like "12 left." Your reading is an estimate, and if the board says 12 and the keg kicks at 7, the board was wrong.
• "Hurry" or "Don't miss out." It reads like an ad.

Pick 1 phrase for each stage and use only those. Once every low line says the same thing, regulars learn to read it. For the order and wording of the rest of the line, see how to write a tap list guests can read fast.

Where does the low mark go if guests don't see it?

A mark guests never see still has to sit where staff will see it: on the tap sheet at the board station, in the pre-shift huddle, and on the handoff. Say it at pre-shift ("tap 6 is low, the hazy is cold"), and carry it on the shift handoff card so the next crew doesn't find out at the kick.

Tape on the handle works too, as long as it's a different signal from the one you use for kicked. A bartender who sees tape should know at a glance whether the line is low or already gone.

How does TapDisplay track keg levels?

TapDisplay keeps a keg level on each item, a number from 0 to 100 that staff type into the item editor by hand. Nothing reads the keg or updates the level automatically. Owners, managers and staff can all edit keg levels, along with the rest of the menu, from a phone, a tablet or a computer behind the bar.

Each connected screen checks for changes every 30 seconds, so an edit shows within about 30 seconds. When a keg is typed down to 0 or the beer is marked kicked, it stays on the TapDisplay board, struck through. On keg menus, such as a brewery, bar, sports bar or cidery, the label reads KICKED. On other menus, such as coffee or wine, it reads SOLD OUT. The word comes from the business type, so you can't type your own.

The level on each item is whatever someone typed at the last check, so the check gap from your worksheet still applies. Keep the low marks on the tap sheet, convert them to the 0 to 100 scale with the keg size math above, and update the level each time someone reads the keg. The activity log shows who changed what, and undo reverses a change if someone types a level on the wrong tap.

The bottom line

Set the low mark per tap, in pours left, from the jobs that have to happen before the kick and how often anyone checks: busiest-hour pours times warning minutes, divided by 60. A single mark like "low at a quarter" means about 31 pints on a half barrel and about 10 on a sixth barrel. Show guests a low note only on lines with nothing behind them, and word it the same way every time.