Bar Inventory Control Basics
There are many methods to assess the inventory in bars and liquor inventory in restaurants. Each supplier of such Bar Inventory claims his being the best and most sophisticated. What are the facts?
Bar Owners and Operators are basically interested in two points:
1.) Is enough stock available and what are the turnovers of certain brands??
2.) Is the quantity of poured liquor matching the revenue in the cash register?
To the lesser extend bar management is also concerned about:
a) Over or under pouring of liquor
b) Dilution of liquor by staff
c) Removal of not empty bottles
d) Free drinks given to Bar Tender friends
A Bar Management system has to at least address these 2 points plus many other features for inventory management based on the measurements. Inventory control and Revenue control is basically based on the measurement of the quantity of either poured drinks or calculated by weighting the remaining liquor in the bottle.
The more correct and least time consuming the measurement result is reported on a notepad, a software generated list or consumption report or as sophisticated as a real time measurement of all liquor activities in the bar.
There are 2 basic methods of measurement:
1.) Assessing the "pouring" by a movement sensor on the bottle
2.) Weighing the bottle using a scale or several scales in case of a real time system
In the table below we compare 3 systems which are widely used in the market. I am not listing the scale only solutions as these are only applicable to bars with about 20 bottles and require only a sharp pencil and a notepad. Some scales offered here are often modified kitchen scales from China worth $15 selling at high prices at various bar control websites.
Comparison of 3 Bar Control Measurement Methods
| Movement Sensor |
Scale System | Real-time Scale | |
| Recognizes the pouring action real time |
Yes, but not the quantity | No, only at time of measurement | Yes, including the quantity |
| Bottle equipped with | RFID or other transmitter equipped Pourer | Work with the bottle barcode | RFID chip on bottle |
| Determines bottle Tare Weight | No | Yes | Yes |
| Knows when bottle is empty | No | Yes | Yes |
| Affected by interference from Cell Phones and similar | Possible, also RFID signal collision possibility with loss of data. | No | No |
| Determines the actual quantity sold | No | Yes | Yes |
| Can calculate revenue based on liquor volume | No | Yes | Yes |
| Detects dilution immediately | No | Possible | Yes |
| Determines specific gravity of liquor | No | Yes | Yes |
| Determines Tare weight of bottle | No | Yes | Yes |
| Total Bar Personnel tracking | No | No | Yes |
| Connects to any existing POS System | Possible | Possible | Yes |
| Suitable for... | Approximate Revenue assessment. | Inventory Management of bars with less than 150 bottles and for inventory loss consultants to collect data. | Total inventory management and control |
| Used by... | Single Unit Operations | Single and Multiple Unit Operations. | Single operations with several bars on premise, Multiple Unit Operations, Chains and Hotel Chains. |
| Main Problem... | Every bottle must have a pourer - some customers dislike pourers. | Not real time | Extensive Installation |
| Pourer / No Pourer | Must use pourer | Individually programmable for pourer or no pourer | Individually programmable for pourer or no pourer |
| Stock Room Management | No | Yes | Yes |
| Main Advantage... | Easy set-up | Low Cost - sophisticated software | Absolute real time and accurate control - professional software |
| Accuracy per measurement | Unknown (see below in Conclusion) | 0.01 oz | 0.01 oz |
| Cost of system for a bar with 150 bottles | $25,000 | $1,500 | $45,000 |
| Priced based on quotes by: | Capton | Bar-Manager.com | Bar-Manager.com |
Conclusion: Scale based systems give reliable and accurate data. Bottle movement systems pretend a 1/10 oz accuracy – but not stated is per drink or per bottle? In one movement a whole bottle can be emptied and it registers only as 1 drink. Drinks can be diluted anytime by removing the pourer and add another liquid. Drinks can be dispensed without detection by simply removing the pourer. Bar Personnel keen to cheat will surely find a way. Scale based system eliminate many of these problems. The real time scale system is so sophisticated that it basically detect any cheat attempt and wrong quantities within seconds and records every transaction in the database including the ID of the person using the system at that time.
If a system is purchased for loss-prevention only scale based systems can produce the required evidence and just by the mere presence of the system produce less cash loss – these system pay for themselves in a very short time by simply having more cash in the register, therefore the slightly higher price of the real time system is really worth it.