Guest Taps: How Many Handles and How Long They Stay

Count guest taps by subtraction: total handles, minus house lines, minus any line that never rotates. Then trim until every guest keg sells through in its run, has a cold spot waiting and has a pitch every bartender can give. On a 16 tap wall with 10 house handles and a fixed cider line, that leaves 5 at most; start with 4. Below: the worksheet, the run types that set how long each guest stays, and how to mark guest lines.

What counts as a guest tap?

A guest tap is a handle reserved for other breweries' beers on a rotation you set. At a taproom or brewpub, that means beer you didn't brew. A handle that takes a new beer of your own at every kick is a house rotator, which is a separate choice and doesn't count toward guest handles. Neither does a core handle, where the same beer goes back on when the keg kicks.

At a beer bar, where every beer comes from somewhere else, core handles carry the beers that always come back and guest handles are the ones meant to change.

To see where you stand, walk the wall and say one word at each handle: core or guest. If you stall on 3 or 4 handles, or your bar manager and your closer would sort them differently, you're pouring guest beers without a guest tap program. A program is 3 decisions, written down: how many handles rotate, how long each guest beer stays, and how the list tells guests which lines are passing through.

How many guest taps should a bar run?

A bar should run the guest taps left after subtracting the handles that can't move, trimmed by 3 checks. No number fits every bar, so the count starts from your own wall.

In this made-up example, a 16 tap beer bar keeps taps 1, 2, 3, 4, 5, 7, 9, 10, 11 and 14 as house handles and pours a cherry cider on tap 15 that never rotates. That's 16 minus 10 minus 1, so 5 possible guest handles: taps 6, 8, 12, 13 and 16.

Treat the 5 as a ceiling. Run each candidate handle through the checks below, then start 1 handle under what they allow. Tap 16 stays a house handle until every guest handle has hit its window for a few weeks running.

Will each guest keg sell through in its window?

A guest keg sells through when it empties inside the run you set for it, and you can test that before you order. You need 3 inputs: the keg size, your usual pour, and how many pours a day that handle sold for its last few guests.

days on the handle = (fluid ounces in the keg ÷ ounces per pour) ÷ pours a day

The Brewers Association's Draught Beer Quality Manual (page 6) lists a half barrel at 15.5 gallons, or 1,984 fluid ounces. A quarter barrel holds 7.75 gallons (992 fluid ounces) and a sixth barrel 5.16 gallons (660 fluid ounces). Counted in 16 oz pours:

Real counts run a little lower after foam and waste. For a handle that mostly pours 10 oz, divide by 10.

Work it backward from the run you want. A handle that pours 6 a day and should change about every 2 weeks needs a keg of about 84 pours or fewer (14 days times 6). A quarter or sixth barrel fits; a half barrel sits there for 3 weeks.

Check your slowest guest handle too. A half barrel on a handle that pours 2 a day lasts 62 days. The same manual (page 50) says beer in kegs on tap for longer than 45 days may have changed in flavor from what the brewer intended. If a handle's guest kegs keep running past their window, you have 1 guest handle too many, or that handle needs smaller kegs.

Is there cold room space for the next guest?

There's enough cold room space when the next keg for every guest handle is cold and waiting before the current one kicks, next to your core backups. Count the spots. If you have room for 3 waiting guest kegs and you run 5 guest handles, 2 of them go dry at the kick or get whatever keg is closest.

Waiting means cold, too. The Brewers Association manual says every keg must be at or below 38°F when it's served. Its chill table (page 51) gives a keg that arrives at 44°F 18 hours to get there, and one at 50°F needs 25 hours. A guest keg that comes in on the day its handle kicks isn't ready for that night.

Set a low mark on each guest handle the way keg levels on the board describes, and use it as the signal to get the next guest into the cooler.

Can every bartender sell it?

A bartender can sell a guest beer when they can give a one-sentence pitch for it on any shift without checking a note. Count how many new pitches your guest handles create:

new guest beers a week = guest handles × 7 ÷ average days each guest stays

5 guest handles averaging 10 days each bring 3.5 new beers a week. If your pre-shift can cover 2, run fewer guest handles or longer runs until the two numbers meet.

Which lines should stay out of the guest rotation?

Cider, flavored beers and anything else that can leave its taste in a line should stay on fixed handles, counted with the lines that never rotate. The Brewers Association's Draught Beer Quality Manual (page 64) says beer lines may need replacing after pouring root beer, flavored beers, wines or ciders. Those drinks can contaminate a line for good, and possibly the lines next to it in the same bundle. Once that happens, the manual says, the line can't be used for beer again.

So rotate non-beer guests on a fixed line of their own, like the cider on tap 15 in the example, and keep them off the beer guest handles.

How long should a guest beer stay on?

A guest beer stays on for whatever run type its handle carries, and every guest handle needs one written down. Three run types work:

In the example, taps 12 and 13 get limited kegs, so each runs one keg.

Whichever run type a handle has, 3 rules go with it:

1. Write the end or review date when the keg is tapped, not when it kicks. A run with no written end turns into a core beer nobody chose.
2. Decide ahead what happens to a slow keg. Either it stays until it kicks and that handle's next guest goes on a smaller keg or a faster style, or it comes off, goes back in the cold room and the next guest goes on. Leave that call to the middle of service and a slow keg ends up sitting on a handle for a month.
3. Have a promotion rule. If a guest beer wins its review twice in a row, decide whether it's core now. If it is, move it to a core handle and give the guest handle back to the rotation.

Keep one run card per guest handle, filed with your on deck list:

GUEST RUN CARD
Handle:            ____
Beer on now:       ____
Run type:          one keg / set run of ___ kegs or ___ weeks / open, review on ___
Tapped:            ____
Review or end by:  ____
If slow at review: ____
Next guest:        ____

Here's a filled card from the made-up example, with placeholder names:

Handle:            8
Beer on now:       Brewery A, Beer name, Gose, 4.5%
Run type:          set run of 2 kegs
Tapped:            Monday, week 1
Review or end by:  Sunday, week 3
If slow at review: stays until it kicks; next guest on 8 goes on a smaller keg
Next guest:        Brewery B, Beer name, Saison, 6.2%

The next guest line feeds your on deck tap list. Which style each guest handle carries is a separate decision. Tap rotation planning covers the grid that keeps the whole wall balanced as guests come and go.

How should guest taps be marked on the list?

Guest taps should be marked so a guest can tell whose beer it is and whether it'll still be there next week. The way you mark them depends on the room.

Taproom or brewpub: bring the brewery back

In a taproom, every guest line carries its brewery, and guests get their own section below your beers. If your own lines drop the brewery because every beer is yours, a guest line without one reads as your beer. The section name does the marking. Here's a made-up 12 tap taproom pouring 2 guests:

GUEST TAPS
11 | Brewery A | Beer name | Pilsner | 5.0% | 16 oz $7 / 10 oz $5
12 | Brewery B | Beer name | Porter  | 6.0% | 16 oz $7 / 10 oz $5

Beer bar: tag guests inside their style section

At a beer bar, leave each guest line in its style section and put a tag at the end of the line. Many beer bar guests shop by style, so a separate guest block makes the IPA drinker read 2 sections. Tie the tag to the run type, since that's what a regular wants to know: GUEST for a set or open run, ONE KEG for one and done.

HOPPY
5  | Brewery C | Beer name | Hazy IPA       | 6.5%  | 16 oz $8 / 10 oz $6
6  | Brewery D | Beer name | West Coast IPA | 6.8%  | 16 oz $8 / 10 oz $6 | GUEST
7  | Brewery E | Beer name | Double IPA     | 9.2%  | 10 oz only $8

BIG AND STRONG
12 | Brewery F | Beer name | Barleywine     | 10.5% | 8 oz only $9 | ONE KEG
13 | Brewery G | Beer name | Imperial Stout | 11.0% | 8 oz only $8 | ONE KEG

In either room, the tag follows the same rules:

• Use a word, in the same spot, spelled the same way on every guest line. Skip stars, and don't rely on color alone.
• Explain it once at the top of the board, in one line: "GUEST: rotating handle. ONE KEG: gone when it kicks."
• Take the tag off the day a guest is promoted to core. A GUEST tag on a beer that has poured for 3 months teaches regulars to ignore the tag.

Everything else on a guest line follows the same field order and wording as the rest of the board, which how to write a tap list guests can read fast lays out.

What has to change when a guest handle switches beers?

The keg on the line, the marker on the handle and the line on the board all change together when a guest handle switches beers.

The Brewers Association manual's pre-service checklist (page 50) has staff pour 1 to 3 fluid ounces at each faucet and confirm the tap marker matches the beer in the line. Run that check at every guest change, and change the board line on the same trip. When the old keg kicks in the middle of a shift instead, what to do when a keg kicks mid-shift has the routine.

What does a guest tap program look like on one sheet?

A guest tap program fits on one sheet that names the guest handles, the default run, the slow keg rule, the promotion rule, the tag and what triggers a recount. Here's the made-up example's sheet:

GUEST TAP PROGRAM (made-up example)
Guest handles:       6, 8, 12, 13 (4 of 16); 16 joins after a few
                     weeks with every guest handle on time
Fixed non-beer line: 15 (cider), never rotates
Default run:         set run of 2 kegs; limited kegs run one keg
Slow keg rule:       stays until it kicks; next guest goes on a smaller keg
Promotion rule:      wins review twice in a row, decide on core
Tag on the list:     GUEST or ONE KEG, end of line, explained at the top
Fallback:            house keg on the handle until the late guest arrives
Revisit the count:   a guest handle misses its window twice running,
                     or cold room space changes

How does TapDisplay show guest taps?

A TapDisplay board shows every line with the beer's name, brewery, style, ABV and a price per pour, so a guest line always says who made it. Each line carries 2 pours by default and up to 4. Guests can get their own section or sit in their style sections.

When a new guest goes on, start typing its name and pick a match from TapDisplay's catalog. The catalog fills in the brewery, style and ABV you haven't entered yet. Staff accounts can make the change from a phone, a tablet or a computer. Each connected screen checks for changes every 30 seconds, so the new line shows within about 30 seconds.

When a guest keg kicks before the next one is ready, the line stays on the TapDisplay board, struck through. On keg menus, such as a brewery or bar, it reads KICKED. The word comes from the business type, so you can't type your own. The activity log shows who changed which handle, and undo reverses a change made on the wrong tap.

The bottom line

Count guest taps by subtraction, then trim until each guest keg empties inside its run, has a cold spot waiting and has a pitch every bartender can give. On the 16 tap example that's 5 at most, started at 4. Write each handle's run type and end date when the keg is tapped. Mark guest lines the same way every time, with the brewery on the line and one tag explained once at the top of the board.