Beer is made from just four ingredients: water, malt, hops and yeast. That's it - just four simple ingredients that brewers have been combining for centuries to create everything from a crisp lager to a dark stout.
Water makes up around 90% of what's in your glass. Malt is what gives beer its colour, body and natural sweetness. Hops bring the bitterness and aroma that balance things out. And yeast is the quiet workhorse turning sugar into alcohol. Four ingredients, endless possibilities, that's the beauty of beer.
The Four Core Ingredients in Beer
Every beer you've ever had, from a £2 supermarket lager to a £6 taproom IPA, starts with the same four basic ingredients. It's what brewers do with them that makes the difference.
1. Water - The Ingredient Nobody Talks About
It's easy to forget that water counts as an ingredient of beer at all. It's just... there, right? But water makes up around 90% of the beer in your glass, which technically makes it the most important ingredient of the lot.
Not all water is the same. The minerals dissolved in it (calcium, magnesium, sulphate, and chloride) change how a beer tastes and feels in the mouth. Too much of certain minerals and a beer can taste harsh or minerally. Too little and it can taste flat and lifeless.
You can actually see this play out in beer history. Burton-on-Trent became famous for pale ales because its water happens to be rich in sulphate, which makes hop bitterness taste sharper and cleaner. London's softer, more alkaline water suited darker styles like porters and stouts. Meanwhile, in Pilsen, the water was about as soft as it gets, which is part of why pale, delicate lagers were born there.
For homebrewers, the good news is that most UK tap water is a perfectly reasonable starting point, and a few simple water treatments can nudge it towards whatever style you're brewing. If you want to start dialling in your water properly, take a look at our water treatment range, everything you need to adjust your brewing water for the style you're making.
2. Malt For Colour, Body and Sweetness
Malt is barley that's been allowed to start sprouting / germinating, then dried before it gets the chance to actually grow. That sprouting process unlocks enzymes inside the grain, enzymes that later turn the barley's starches into sugars yeast strains can feed on. Maltsters control this by steeping the grain in water, letting it germinate for a few days, then drying it down in a kiln to lock in the changes.
Most beers start with a base malt, things like pale malt or pilsner malt, which supply the bulk of the fermentable sugar and a fairly light colour. Speciality malts are used in smaller amounts to add character. Crystal malt brings a caramel sweetness and sometimes a reddish hue. Chocolate and roasted malts go darker still, pushing towards coffee, toffee, even a faint burnt toast note. The darker the roast, the darker and more intense the beer.
Shop our malt range, milled fresh to order so you're brewing with malt at its best.
3. Hops for Bitterness, Aroma and Everything in Between
Hops are the cone-shaped flowers of the Humulus lupulus plant, a climbing perennial native to Europe, West Asia and North America. Inside those cones are acids and oils that give beer its bitterness and its aroma.
Add hops early in the boil, and you draw out bitterness, since the acids in the hops need heat and time to isomerise and dissolve. Add them late, or after the boil entirely, through whirlpooling or dry hopping, and you capture more of their aroma and flavour instead, without much bitterness coming through. That's why a hop-forward IPA tastes so different from a balanced bitter, even when similar hop varieties are involved.
Different varieties bring completely different character too. Some, like the classic English hop Challenger, lean bitter and earthy. Others, like the American variety Citra, are prized for bright, citrusy aromatics. Picking the right hop and adding it at the right moment is where a lot of the creative fun in brewing happens.
Shop our hop range, cold-stored and nitrogen-flushed to keep every hop as fresh as the day it was picked.
4. Yeast - The Ingredient That Makes Beer, Beer
Yeast is the beer ingredient that turns sweet, sugary wort into actual beer. It belongs to the genus Saccharomyces cerevisiae, and during fermentation, it consumes the sugars from malt and converts them into alcohol and carbon dioxide.
The big split in the brewing process comes down to ale yeast versus lager yeast. Ale yeasts ferment at warmer temperatures, traditionally rising to the top of the fermenter, while lager yeasts work at cooler temperatures and settle at the bottom. That difference alone explains why ales tend to taste fruitier and more complex, while lagers come out cleaner and crisper.
Ale yeasts are traditionally used to make top-fermented beers, rising to the surface as they work. Lager yeasts make bottom-fermented beers, settling down at the base of the fermenter instead. It's part of why ales have historically been easier to brew at home; you don't need much more than a bucket and a warm corner of the kitchen, whereas bottom-fermented beers take longer and traditionally need consistent cold temperatures to do their thing properly. Most homebrewers start with a top-fermented beer for exactly this reason. In recent years new afforable pressure fermenters have opened up the concept of making quality lagers at warmer temperatures at home.
The specific strain matters too (we sell over 50 different strains). Different types of yeast produce different flavour compounds as they ferment: fruity esters, spicy notes, sometimes a faint butteriness, and the strain you choose shapes the finished beer almost as much as the malt and hops do. Stressed or unhealthy yeast can throw off unwanted flavours, so looking after it properly (this mostly means controlling fermenting temperature) is one of the quiet skills of good beer brewing.
Shop our yeast range and find the right strain for whatever you're brewing next.
Beyond the Four - Adjuncts and Speciality Ingredients
What Are Adjuncts in Beer?
Adjuncts are extras that brewers add alongside malted grain. None of these replaces the core four ingredients; they just give brewers more to play with.
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Oats give beers like stouts and NEIPAs (New England IPAs) that silky, smooth body.
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Wheat is what makes a hefeweizen hazy and gives it that soft, bready character. Its also often added to hazy hop forward beers to increase mouth feel and create haze.
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Rye adds a peppery edge to a rye pale.
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Corn (Maize) and Rice lighten the body of a beer and give a crisp sweetness - ideal for lighter lagers
Speciality and Flavour Additions
Plenty of craft beers go further still, fruit, spices, coffee, chocolate, even honey. Done well, these additions complement the beer rather than overpower it; think coriander and orange peel in a witbier, or coffee in an imperial stout. Done badly, they can feel like a gimmick rather than a flavour that actually belongs.
Finings and Clarifying Agents
Finings like isinglass and gelatine help clear cloudy beer by pulling leftover yeast and proteins out of suspension. Isinglass and gelatin come from animal sources, so they're not vegan/veggie-friendly. Irish moss, a seaweed derivative, is.
How Each Ingredient Affects Beer Style
Why a Stout Tastes Nothing Like a Lager
Same four ingredients, wildly different results. Roasted malt versus pale malt changes everything from colour to whether you taste coffee or biscuit. Ale yeast versus lager yeast decides whether a beer comes out fruity and warm or clean and crisp. Fermentation temperatures further affect how the yeast works - cooler lager temps giving clean tasting results whereas ales are fermented warmer to give fruity or spicy flavours. Heavy hopping versus light hopping is the difference between an IPA's punch and a lager's gentle bitterness. Style is really just a set of ingredient and brewing process decisions.
How Commercial Breweries Source Their Ingredients
Big breweries buy malt, hops and yeast at scale, prioritising consistency and cost across millions of pints. Craft breweries tend to go the other way, working with smaller maltsters and hop growers, often choosing quality and character over price. That difference in sourcing is a big part of why craft beer tastes the way it does.
The Reinheitsgebot - When Beer Could Only Have Four Ingredients
In 1516, Duke Wilhelm IV of Bavaria (Germany) decreed that beer could only be brewed from water, barley and hops (yeast came later, once anyone understood what it actually did). The Reinheitsgebot is one of the oldest food regulations still recognised today, and it's still shaping how a lot of traditional German beer gets made.
Can I Use the Same Ingredients to Brew Beer at Home?
Yes - and It's Simpler Than You Think
Same four ingredients, same basic principles, just on a much smaller scale. If you can follow a recipe in the kitchen, you can brew beer at home.
Where to Buy Ingredients for Home Brewing in the UK
Freshness is everything. Malt should be milled close to when you brew with it, not sitting around for months. Hops need to be stored cold and oxygen free to hold onto their aroma; anything stale loses the qualities that make it worth using in the first place. Good ingredients are the single biggest factor separating a great homebrew from a mediocre one, often more than the recipe itself.
Browse our full ingredients range, or if you're just starting out on your all grain journey, our all grain kits for beginners come with everything measured out and ready to go.
What Ingredients Do I Need to Brew My First Beer?
A lot of new brewers psych themselves out before they've even started, picturing something far more complicated than it actually is. Your first brew needs the same four ingredients as every beer ever made, just in smaller quantities:
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Malt (or malt extract if you want to keep things simple)
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Hops, usually just one or two varieties to start
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Yeast: just a single packet is all you need
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Water, the stuff from your tap is fine to start with.
A really simple first beer is one of our SMASH kits. Single Malt And Single Hop and a packet of yeast.
And that's really it, water, malt, hops and yeast, with a bit of history and a lot of room to experiment. Hopefully, you've got a better sense of what ingredients are in beer, and maybe even fancy having a go at brewing at home yourself. If you've got questions, whether it's choosing your starting equipment or what just where to start, drop us a message. Jonny and the team are always happy to chat; no question is too daft!
What are the Ingredients in Beer and Other FAQs
What are the main ingredients in beer?
Water, malt, hops and yeast. That's it, just four ingredients for pretty much every beer style out there.
Are beer ingredients natural?
Yes. Water, malted barley, hops and yeast are all natural ingredients. Some beers use adjuncts like corn or rice too, which are also natural, just less traditional.
What is malt made from?
Barley that's been soaked, allowed to sprout (germinate), then dried. That process is called malting and it unlocks the enzymes and starches that hlep make the sugars yeast needs to make alcohol.
What do hops do in beer?
They add bitterness, aroma and flavour. Added early in the brew they bring bitterness, added late or after the boil they bring flavour and aroma instead.
Can you brew beer without hops?
Yes but its not called beer - its called a gruit. Historically brewers used other bitter herbs, but it wouldn't taste like the beer most people know today. Hops are pretty much essential to modern ber brewing.
What's the difference between ingredients in craft beer vs mass-produced beer?
Mostly freshness and quality. Craft brewers tend to use specialist malts and hops in smaller batches, while mass-produced beer often relies on cheaper commodity ingredients at scale. Some commercial beers don't actually use any actual hops - they use hop oils (concentrated oil made from hops to add bitterness).
Where can I buy home brewing ingredients in the UK?
Right here at BrewKegTap. We stock fresh malt (milled to order), hops (nitrogen flushed, foil packed, sotred cold) and yeast (stored cold), browse our ingredients range to get started.
Is beer vegan / vegetarian?
Not always. Some beers use animal-derived finings like isinglass or gelatin to clear them. Always worth checking the label if you're brewing or buying vegan.