Putting a new line on the bar: the four setup mistakes that wreck the next stocktake

Every new line on the bar is four facts: what it comes in, what you serve it in, what it cost and what you charge. Get one of those wrong in the till or the stock system and the next stocktake shows a loss, or hides one, that has nothing to do with anybody behind the bar. Most first-stocktake shocks after a range change are setup, not shrinkage.

Range changes happen all the time. A guest ale, a lager swap, a new craft keg, a cider for summer, a gin someone's rep talked you into. Each one gets set up in a hurry, usually on a busy day, usually by copying the line it replaced. That's where it goes wrong.

Mistake one: the wrong container size

This is the expensive one. Kegs come in more sizes than people think, and a craft keg in particular is often not the same size as the lager it sits next to. The pints per container, using 568ml to the pint:

Container	Pints, before any waste
50 litre keg	88
11 gallon keg	88
30 litre keg	52.8
20 litre keg	35.2
Firkin (9 gallons)	72
Polypin	36

Now set a 30 litre keg up in the system as a 50, because you copied the lager it replaced. Every time a keg goes, the system expects 88 pints rung and you can only ever ring 52 or so. That's 35 pints of loss per keg that never existed, about £157 at the £5.34 average pint once VAT is out. Get it the other way round, a 50 set up as a 30, and the system hands you 35 free pints a keg that quietly cover a real loss somewhere else. The second one is worse, because nobody goes looking.

Check the container size off the delivery note or the keg itself, never off the line it replaced.

Mistake two: the price in the wrong VAT basis

Some systems want the selling price including VAT, some want it without, and the field rarely says so loudly enough. StockTap's sell price field, for what it's worth, is ex-VAT, because that's what GP should be worked out on.

Type the shelf price into an ex-VAT field and the maths flatters you. Same pint, £5.34 on the board, £1.56 cost: worked out properly on £4.45 ex-VAT it's 64.9% GP. Typed in at £5.34 as if that were the ex-VAT price, the report says 70.8%. Nearly six points of GP that don't exist, on one line, and it makes that line look like your best seller for margin. I've written up the VAT basis and why GP reports disagree separately if you want the long version.

Mistake three: no button, or the old button

If the new product isn't on the till yet, the drink still gets served, and it gets rung on whatever is nearest. Usually the line it replaced, or something at a similar price. That's not anyone being careless. The till gave them no other option and the customer was stood there.

It leaves a signature you can spot. One line comes out down by roughly the same number of serves that another comes out up. If your new lager is 30 pints short and the old one, which you no longer stock, somehow sold 30 pints, that's your answer. It's the same pattern as wrong till buttons generally, it just shows up all at once after a range change. Put the button on before the first keg goes on, and delete or hide the old one the same day.

Same goes for serves. If you're adding a two-thirds measure, it needs its own button and its own serve size in the stock system. Draught beer and cider can legally be sold in a third, a half, two-thirds or multiples of a half, so a schooner is fine, but ring it as a half and every one is a sixth of a pint unaccounted for. The measures guide has the rest of the rules.

Mistake four: the cost price off the wrong bit of paper

The cost you set up a new line with is often the one on the price list or the rep's email. The cost you pay is the one on the invoice, which might include an introductory deal on the first order that disappears on the second. Set up the line at the deal price and your GP on it slides from the second delivery onwards without anyone touching a pump.

Use the invoice, check it again on the second delivery, and if the price moves, the price-rise guide has the sum for how much the shelf price needs to move to hold your GP.

The pull-through: write it down once

When a new product goes onto an existing line, you pull through until it runs clean. That beer is real stock leaving the keg with no sale against it. How much depends entirely on your run. As a guide to scale, a standard 3/8 inch bore line holds about 71ml a metre, which is just the geometry, so a 15 metre run is close to two pints sitting in the pipe before you've poured anything.

Don't guess it. Pull it into a jug once, measure it, and write the number in your wastage log every time you change that line. It's the same logic as line cleaning: once it's measured and written down, it stops being part of the mystery.

The first fortnight on a new line

The cheapest fix is to count the new line on its own for the first two weeks. Not the whole bar, just that line, every couple of days, against what was rung. It takes two minutes and it catches all four mistakes before they get averaged into a full stocktake where they are much harder to find.

What the count shows	Most likely cause
Short by roughly the same amount every keg	Container size set up wrong
Short, and an old or similar line is over by the same	Missing or wrong till button
Pints add up but GP looks too good	Price entered in the wrong VAT basis
Pints add up but GP slips from the second delivery	Cost price taken from a deal, not the invoice
A small gap only on the first keg	Pull-through not logged

If the gap survives all of those, it's a normal variance question and you treat it like any other, starting with what acceptable looks like.

Setting up a new line in StockTap

Same four facts. Container size, serve size, the cost per container from the invoice and the sell price ex-VAT. Put the new line in before it goes on, count it on the day it does, and use the daily spot check for that one line through its first fortnight. What StockTap can't do is check your till, so the button is still your job.

Common questions

How many pints are in a 30 litre keg?

About 52.8 pints before any waste, against 88 in a 50 litre or 11 gallon keg. Real sellable pints are always a bit lower once line cleaning and fobbing are taken out.

Why is my stocktake down after changing a beer?

Usually setup rather than loss. Check four things in order: the container size in the system, whether the new product had its own till button from day one, whether the price was entered in the right VAT basis, and whether the cost price came from the invoice.

Can I sell beer in a two-thirds pint glass?

Yes. Draught beer and cider can be sold in a third, a half or two-thirds of a pint, or multiples of a half pint. Give the two-thirds measure its own till button and serve size, or every one rung as a half leaves a sixth of a pint unaccounted for.

Should I log the beer pulled through when changing a line?

Yes. Measure it once into a jug for each line and record it every time you change product on that line. It's real stock out of the keg with no sale against it, and unlogged it looks like loss.