How To Audit Your Bar’s Glassware

Your glassware is one of the most important inventory control tools you have. They are not just for presentation. They are portion control tools that can play a big role in making or breaking your business.

Yet, it is one of the last places operators look when considering their best paths to profit. Each operator would do themselves well if they audited their glassware occasionally, with random tests and occasional brainstorming sessions about better options in the market.

In this article, I will review a few key components of glassware all operators should know, and then make a few recommendations for optimal glassware selection.


1. All bar operators should know the differences between Imperial and Metric Ounces

America, Liberia, and Myanmar are on the imperial system, while everyone else uses the metric system. For the sake of this discussion, I will label imperial as “American” and metric as “Canadian” (since that’s where I live).

  • American ounces are 30 ml.
  • Canadian ounces are 28.4 ml.

The 1.6 ml difference is an approximate 5% variance up or down, depending on what side of the border you are on.

It doesn’t sound like much, but consider the following:

  • A 750 ml bottle with 30 ml American ounces will give you 25 servings.
  • A 750 ml bottle with 28.4 ml Canadian ounces will give you 26.4 servings.
  • That 1.4 ml serving difference, if you sell each ounce for $6.00, is valued at $8.40 per bottle.

If you sell four bottles of vodka per week, that is $33.60 per week and $1,747.20 over the course of a year. So, if you are operating a bar in Canada or another country using the metric system, it pays big to make sure you are using the correct 28.4 ml shot glasses.

2. Some Notes on Shot Glasses

You may have never actually sat down to look at your shot glassware before. But now that you know some glasses vary slightly depending on their manufacturing origin, it may be smart to examine your glassware and make sure they’re all correct for your region.

America is a manufacturing giant for the bar industry, and their glassware is everywhere. I have found American glassware in several Canadian bars and restaurants, and operators that unknowingly have them in-house lose thousands of dollars each year without any knowledge anything is going wrong. This is because the losses that occur from incorrect glassware are slow and insidious. They do not break you immediately, but they just keep you poorer than you should be over a long period of time. To ensure this doesn’t happen, it’s a good idea to test your glassware every now and then.

How to test shot glassware is simple:

  1. First, put glass on a scale.
  2. Tare the scale.
  3. Set units to grams.
  4. Fill the shot glass to the top with some booze and observe the weight

If the weight is 28 grams, then it is Canadian / Metric. If it is 30 grams, it is American. If it is more than 30 grams, then the shot glass is poorly designed and not optimal for commercial use.

bar glassware inventory control
(Photo: Bogdanhoda, iStock / Getty Images Plus)

3. Some Notes on Draught Beer Glassware

Draught beer is big business now, and some beverage operations have as high as 40% of their overall beverage sales from draught beer. So, it very much matters what glassware you select and place behind your bar.

Beer glassware is commonly available in 12, 16, and 20-ounce glasses. And just like shot glasses vary, so do beer glasses. American pints are commonly 16 ounces, and Canadian are commonly 20 ounces. (Although I must state that it is normal now in Canada to see bars serving 16-ounce portions and calling them “pints.”)

Let’s assume you have proper 16-ounce glasses behind the bar, and your menu advertises 16-ounce pours. What you need to know about beer glassware is:

  • The pour line is where the liquid content equals the stated capacity.
  • If the pour line is at the very top, or brim of the glass, then theoretically, you can never overpour.
  • However, if it is below the top of the glass, then it is very likely you will overpour on every serving.

This can become a big problem with branded glassware that has a pour line well below the brim. Manufacturers will tell you that the branded glassware “enhances the customer experience,” but in reality, all those glasses will do is cost you money. This is especially true of “chalice-like” glasses that require an inch or more of head to be poured “properly.” The proper amount of head is a subjective measurement that will differ with each bartender. This will always result in lots of overpouring.

The ideal setup is when you buy glassware with its capacity set at the brim of the glass and ensure your advertising matches up with the capacity of the glass. This way, if you advertise a 16-ounce pint, and the glass holds 16 ounces to the brim, you can rest assured you will never overpour beyond your theoretical because it’s impossible to pour more than 16 ounces in each glass. In fact, in this scenario, you would actually save anywhere from 1-1.5 oz per pint because when the head on each pour settles, the liquid will be below the brim.

As you can see now from examples in shot and beer glassware, the value of using glassware as a portion control tool can never be overstated and is a common principle that applies to every area of your operation.

4. Some Notes on Wine Carafes

Wine poured by the glass is a very common area of shortages for every bar, and the main challenges usually stem from the use of carafes as portion control tools.

Typical pour sizes for wine include: 5 ounces, 6 ounces, and 9 ounces. Occasionally, there will be half bottle pours that exceed those, but they are not as common.

It is common with wine carafes to have the pour line below the brim of the carafe itself. Because of this, using this tool and method requires subjective judgment from each bartender. And just like the chalice style beer glasses mentioned above, any time the pour line is below the brim of the container, this will result in variances.

Instead, if you have a cylinder that holds 6 ounces at the brim, it is impossible to overpour. And while wine carafes may be part of the presentation of wine in a higher-end experience, it may be a wise move for operators to consider using a cylinder to pour the wine into the carafe at the service well instead of using the carafe itself as the portion control tool. This way, the guest receives their wine presented in the glass carafe, and the operator ensures that they will never consistently overpour during the course of their operation. In fact, using the cylinder in this fashion would result in a slight retention of 0.1-0.5 oz per pour because no one would actually pour the cylinder all the way to the brim, as it would spill over.

These concepts about bar glassware can be applied to every area in your business where portion control is done with tools (like your kitchen). When carefully scrutinized and tested, this can be an unlikely place you can create more profits without any extra effort.

Kevin Tam is a Sculpture Hospitality franchisee with more than a decade of experience working directly with bar, restaurant, and nightclub owners on all points of the spectrum. From family-owned single bar operations to large companies with locations on an international scale, Kevin works with them all and understands the unique challenges each kind of company faces. He’s also the author of a book titled Night Club Marketing Systems – How to Get Customers for Your Bar, a regular writer/contributor for Bar & Restaurant.


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