Every beer label carries a small percentage figure that most people glance at without really thinking about - "5.2%", "4%", "6.5% ABV". We get asked what it actually means more often than almost anything else on our tours, usually somewhere around the second or third taproom, once someone's noticed the beers are getting a bit stronger as we go. ABV is one of the simplest ideas in brewing once it's explained properly, but it's also one of the most useful numbers you can actually use - both for understanding a beer before you order it, and for pacing yourself sensibly across an afternoon of tasting. Here's what it means, how it's measured, and how we build it into the order we pour beers on our own guided tours.
What ABV actually stands for
ABV stands for Alcohol by Volume - the percentage of the total liquid in your glass that is pure alcohol. A beer labelled 5% ABV is exactly that: 5% of the liquid, by volume, is alcohol, with the rest made up of water, unfermented sugars, proteins and the flavour compounds that give a beer its character. It's a legal requirement on every beer sold in the UK, printed on the can, bottle or pump clip, and it's the same measurement used across wine and spirits too, which is why you can compare a 5% pint directly against a 13% glass of wine on genuinely equal terms.
It's worth being clear that ABV measures strength, not quality or flavour intensity. A characterful 3.8% session pale ale can be more hop-forward and interesting than a bland 7% double IPA brewed purely to hit a number - ABV tells you how much alcohol is in the glass, nothing more.
How brewers actually measure it
The maths behind ABV comes down to fermentation. Before fermentation starts, a brewer measures the specific gravity of the liquid - essentially how much dissolved sugar it contains, since sugar makes liquid denser than water. Once yeast has eaten through that sugar and converted it into alcohol and carbon dioxide, the brewer measures the gravity again. The bigger the drop between the two readings, the more sugar was converted, and the higher the final ABV. Our guide to how beer is actually made covers the mashing and fermentation steps behind that gravity drop in more detail if you want the fuller brewing picture rather than just the sums.
This is also why bigger, maltier beers - barleywines, imperial stouts, strong Belgian-style ales - tend to run stronger than crisp lagers or session pales: they're brewed with far more fermentable sugar to begin with, giving the yeast more to convert. A brewer can also leave some sugar unfermented deliberately, which is one reason two beers with similar amounts of malt can still land at noticeably different ABVs.
Typical ABV ranges by style
ABV varies enormously by style, and knowing the rough bands helps you read a tap list at a glance rather than being surprised halfway down a pint. As a general guide: session beers and light lagers usually sit between 3% and 4.2%, our guide to what makes a beer a "session" beer covers that lower end properly. Standard lagers, pale ales and wheat beers typically run 4% to 5.5%. Hoppier pale ales and most IPAs land between 5.5% and 7.5%, with hazy and double IPAs often pushing toward the top of that range or beyond it. Porters and stouts vary widely, from a modest 4% dry stout up to imperial versions well into double figures. Barleywines, doppelbocks and other "strong ale" styles regularly reach 8-12% or more - if you want the genuine extremes, our piece on the strongest beers in the world covers how far brewers have actually pushed ABV, including some notable UK entries.
None of these bands are fixed rules - a brewer can build a 6% session-style pale ale or a 3.5% "small" IPA if they choose - but they're a reliable starting point for guessing roughly what you're about to drink before the first sip.
Using ABV to pace yourself properly
This is the practical bit, and it's exactly what we think about when we plan the order of beers on our own tours. ABV converts directly into UK alcohol units - a standard formula is ABV × volume in millilitres ÷ 1,000 - so a 568ml pint at 5% ABV works out at roughly 2.8 units, while the same pint at 7% comes to around 4 units. Our guide to units in a pint of beer walks through that maths properly with a full table by style and strength, and it's worth reading alongside this one if you're trying to pace a whole afternoon rather than a single pint.
The simplest habit, whether you're at a taproom bar or hosting your own tasting, is to order roughly low-to-high: start with something in the 4% region, and let the ABV climb gradually rather than opening with the strongest beer on the board. It's the same logic used for flavour pacing - light before dark, low bitterness before high - but applied to strength instead, and it genuinely helps you stay sharp enough to actually notice what's different about the stronger beers later on, rather than blurring through them. Checking the ABV on the board before you order, and roughly tallying units as you go, is a small habit that makes a real difference across a long session. The NHS and Drinkaware guidelines of no more than 14 units a week, spread across several days, are worth keeping in the back of your mind on any beer-heavy day out.
How we build ABV into our own tours
We think about this properly rather than leaving it to chance. Our Bermondsey Beer Tasting Tour (£49pp, 2-3.5 hours, beer included) moves through four independent taprooms starting at Southwark Brewing Co (46 Druid St), and the beers poured at each stop are chosen with a sensible ABV curve in mind rather than getting progressively stronger by accident. If you'd rather pair the tasting with proper food, our Cheese, Meat & Beer Tour (£65pp, Saturdays, 12pm-2:30pm) does the same thing alongside cured meat and cheese at each stop, which also helps slow the rate alcohol hits your system. Further east, our Hackney Wick Craft Beer Experience (£41.25pp, selected Saturdays) runs the same principle through the canalside taproom cluster. All three work for private groups from six people up to 60 or more via private and group tours, and we've been running them since 2014 - long enough to know that a sensibly paced afternoon beats a fast one every time.
Our honest take
ABV is a genuinely simple number once you know what it's measuring - the proportion of pure alcohol in the glass - and it's worth actually reading rather than skimming past on a tap list. Use it to guess roughly what you're about to drink, to convert into units if you're keeping track across a session, and to order sensibly from low to high across an afternoon rather than starting strong and hoping for the best. If you'd rather someone else had already thought about the order for you, that's exactly what we build into our guided tours. A gift voucher for any of them, bought directly on our gift vouchers page, is delivered by email instantly and never expires - a solid present for anyone who'd enjoy tasting properly rather than just drinking quickly.