Brewery Inventory Management: How to Count Beer by Volume, Not by Keg

Most taprooms know what they sold last night in dollars. Far fewer can say how many ounces of a particular beer left the cooler, or how much of it is still in there. That gap is what brewery inventory management closes, and it is mostly a counting problem rather than a technology problem — though the counting gets much easier when the brewery POS does it on every pour instead of once a week on a clipboard.

Depletion is the amount of product removed from stock by sales. A depletion report tells you how much beer left the cooler over a period, measured in the unit you sell by — ounces — rather than in kegs or units. Counting by the container is what makes a half-empty keg look full on a report.

What Is Brewery Inventory Management?

Brewery inventory management is the practice of tracking beer and supplies from the loading dock to the glass. For a taproom it means counting kegs by remaining volume, not by unit, so a half-gone keg reads as half a keg. Done in the POS, every pour depletes stock automatically instead of weekly by hand.

It is a separate job from working out what you are losing to foam, line cleaning and over-pours. If that is the question, start with how to cut draft beer loss instead — this post is about knowing what you have.

How Do You Keep Track of Keg Inventory?

Count kegs by remaining volume, not by container. Set each beer's unit to ounces in the POS so every pour depletes stock automatically, record full kegs as they come out of the cooler, and reconcile against a physical count once a week. The POS tracks what sold; the count catches what did not.

The reconciliation is the part operators skip, and it is the part that works. One independent production brewery that also runs a taproom described the routine plainly: "And then what I do is I do physical inventory of beer once a week and I make those adjustments in Ollie." The POS is not replacing that count. It is making the number you compare it against a real one.

The failure mode is a cooler nobody has told the system about. As the owner of a single-location taproom put it: "let's say we have three back there… one of them runs out, they go swap it. Is that reflected in the back end?" If the answer is no, the count and the system drift apart until the next manual reset.

The routine that works is short and fixed:

1. Count at the same point in the week, before service, so the numbers are comparable week to week.
2. Record full kegs as full, and weigh or gauge partials so a half-gone keg is logged in remaining ounces.
3. Note anything swapped mid-service that nobody entered — this is where the drift starts.
4. Pull the POS depletion report for the same period, in ounces.
5. Compare the two per product, not just in total. A total can net two errors into zero.
6. Reset the POS stock level to the physical count, and record the variance rather than absorbing it.

How Do You Calculate Liquor Inventory?

Opening inventory plus purchases minus closing inventory equals usage. Count in the unit you sell in — ounces for draft and spirits, not bottles or kegs — so usage can be compared against what the POS says you sold. The gap between the two is your variance, and it is the number worth watching.

That comparison only works if both sides use the same unit, which is where most taprooms lose an afternoon. A brewpub operator described the conversion they were doing by hand: "converting it to pints to ounces and then ounces divided by gallons." It is arithmetic a system should do once and never ask about again. Here is the table it is doing:

1. Half barrel (full size) — 15.5 US gallons · 58.7 litres · 1,984 fl oz · 124 × 16 oz pints · 198 × 10 oz pours
2. Quarter barrel (pony) — 7.75 gallons · 29.3 litres · 992 fl oz · 62 pints · 99 × 10 oz pours
3. Sixth barrel (sixtel) — 5.16 gallons · 19.5 litres · 660 fl oz · 41 pints · 66 × 10 oz pours
4. 50 litre (import) — 13.2 gallons · 50 litres · 1,690 fl oz · 105 pints · 169 × 10 oz pours
5. Cornelius (5 gallon) — 5 gallons · 18.9 litres · 640 fl oz · 40 pints · 64 × 10 oz pours

At 128 fluid ounces to the US gallon, pour counts rounded down. Set the unit once, in ounces, and flights, half-pours and 10 oz snifters all deplete correctly without anyone converting anything.

Worked through, on one beer over a week:

1. Opening count — two half barrels, 3,968 oz
2. Purchases — one half barrel delivered, 1,984 oz
3. Closing count — one full half barrel plus a full sixtel, 2,644 oz
4. Usage — 3,968 + 1,984 − 2,644 = 3,308 oz
5. POS says sold — 195 pints at 16 oz, 3,120 oz
6. Variance — 188 oz, or 5.7% of usage: just under twelve pints

Whether 5.7% is good or bad is a different question, and one this post deliberately leaves to draft beer loss. What matters here is that the number exists at all, per product, every week. A variance you can see is a variance you can chase.

How Much Inventory Should a Bar Carry?

Enough to cover the gap between deliveries plus a buffer for your busiest week — usually one to two weeks of stock for draft, longer for spirits that do not spoil. Set a par level per product rather than a total, because the risk is running out of one popular beer, not running out overall.

Par levels are also what turn a stock count into an action. When the count on a product hits zero the POS can do one of three things: nothing, disable the product so it disappears from the menu, or 86 it so it is marked temporarily out of stock and returns automatically the next morning. For a rotating tap list, 86 is almost always the right setting.

Does Product Sitting on the Shelf Affect Bar Inventory?

Yes, in two ways. It ties up cash that is not earning anything, and for draft it has a clock on it — a tapped keg loses quality within weeks, and an untapped one has a shelf life measured in months. Slow movers should be counted, costed, and either promoted or delisted.

Seeing that requires a volume report rather than a sales report, which is not always the same screen. An operator at an independent production brewery with a taproom asked for exactly this: "So how do I pull a report for August that shows the volume, not just the dollar sales but the volume of beer we sold?" Dollars tell you what earned; ounces tell you what moved. A slow beer at a high price can look healthy in one report and dead in the other.

Does a POS Replace Brewery Inventory Software?

No, and it should not try. Production, batches, cellar management and TTB reporting belong in brewery software. The POS owns the taproom side — what poured, in what unit, at what price, and what is left in the cooler right now. The useful arrangement is the two systems reconciling against each other, not one pretending to be both.

The manager dashboard is where the taproom half lives: stock levels by product, depletion by volume, and sales by zone so a patio or an event bar can be read separately from the main room.

Brewery Inventory Management FAQ

What is bar inventory?

Bar inventory is everything behind the bar that gets sold or used — kegs, bottles, cans, spirits, mixers and garnishes — counted in the unit it is sold in. For draft that means ounces rather than kegs, because a keg is rarely full or empty at the moment you count it.

How do you keep track of alcohol inventory?

Count on a fixed schedule, always in the selling unit, always with the same person if you can. Let the POS deplete stock automatically on every sale, then reconcile that against a physical count weekly. The difference between the two is variance, and a consistent variance is more useful than a perfect count.

How many pints are in a half-barrel keg?

124 sixteen-ounce pints. A half barrel holds 15.5 US gallons, which is 1,984 fluid ounces. At a 10 oz pour you get 198, and in practice you will get fewer than either once foam and line loss are counted.

How often should a taproom count kegs?

Weekly is the common rhythm and a reasonable default. Count more often if variance is high or unexplained, less often only once variance has been stable for months. Counting at the same point in the week matters more than counting frequently.

Does a POS replace Ekos, Beer30 or Ollie?

No. Those manage production, batches and compliance reporting. A POS manages what happens in the taproom. The two should exchange data so the taproom's depletion shows up against the brewery's batch records, which is what makes a weekly count quick rather than a reconstruction.