By definition, beer is made of grain: it’s the source of all the sugar for fermentation. As a result, beer has been called liquid bread. And think of the variety of bread that exists. From the lightest bao bun to the darkest pumpernickel, all of that character is contained within beer. The most common grain used is barley, but the way the grain is kilned is what contributes the difference in flavour and colour.

Picture a toaster. On the lowest setting (let’s call it one), you’re going to get the lightest browning possible. It’s going to let the flavour of the grain shine through. However, if you turn the dial up to five, you’re also changing the end result. You’re going to get something a little darker with nutty flavour and a toasty, golden brown crunch. And if you crank the dial as far as it goes, you’re going to get burnt edges and set off the smoke detector.

Kilning malt and toasting bread create a lot of the same flavours, and the colour of your beer is a good predictor of the “weight” of the beverage in front of you. Colour and flavour are a result of the grist used, and typically the darker malts with more assertive flavours make up a minority of that mixture. The caramelization and Maillard browning that take place during malting take place in cooking as well.

Consider that pub classic fish and chips. Well, everything going on there in terms of cooking is deep-fried Maillard reaction, from the breading on the fish to the crispness of the chips. Is it any wonder that Pale Ale and Vienna Lager are standard choices because they match the weight of perfectly fried golden brown goodness? It’s a complementary pairing.

Acidity

By definition, all beer is acidic. In fact, the scale by which we measure acidity was invented by the Carlsberg Laboratory, the biochemical wing of Denmark’s most famous brewery. At the beginning of the brewing process, as soon as malt is added to the mash tun, we’re at 5.5 pH. The finished product is lower than that. A bog standard pint of lager (the kind your dad drank) sits a little lower than 5 pH, but a stout with a lot of dark malt may be closer to 4 pH. The newer varieties of North American mixed fermentation beers use lactobacillus to lower their pH into the range of grapefruit and lemon juice, around 3.

It’s a wide palette from which to paint, and one that affords a lot of opportunity to play. A standard pairing for oysters has always been a Dry Irish Stout like Guinness because of the subtle tangy acidity that exists beneath the cover of roast barley. Or consider a modern mixed-fermentation beer, like Bellwoods’ Jelly King or Sawdust City’s Coriolis Effect Berliner Weisse. Their acidity provides contrast to the deeply saline liquor of the oysters and also provides that spritzy squeeze of citrus, saving you the necessity of preparing garnishes. (Horseradish is, as always, a personal choice.)

Carbonation

You’d be hard pressed to find a beer that isn’t at least marginally carbonated; it’s one of the natural outcomes of the fermentation process along with alcohol. Of course, there are outliers but, even with English-style Ales on cask service, the proper amount of carbonation is an important feature.

The amount of carbonation is highly variable between different styles of beer. The scale runs from still, at about one volume of Co2, to approximately four volumes in bottle-reconditioned German and Belgian styles. While this falls slightly short of the typical 6.5 volumes in sparkling wines, it does present a spectrum of carbonation across the entire range of beer styles.

Intense carbonation certainly has the ability to cut through fat and refresh the palate between bites, but more subtlety may be called for in lighter dishes. Any canapé with a thick, fatty, unctuous texture can be refreshed by a high-carbonation beer. Try a chicken liver terrine or just about any chèvre appetizer alongside that classic Belgian Golden Ale, Duvel, but be careful when pouring it. Carbonation means the potential for a fluffy, rocky head.

If you’re going to think about pairing beer with food, it helps to know a little bit about hops. For our purposes, we’re going to think about them as ingredients in cooking. The female flower of the hop plant looks a little like an artichoke, and there’s a similarity: all of the useful material is at the bottom of each leaf. What we’re looking for from hops is the resin hidden at the base of each leaf. That resin contains essential oils and the potential for bitterness.

When brewers are looking for bitterness, they add hops early in the process of brewing, at the beginning of the boil. It takes 60 minutes for hops to isomerize, or give up that bitterness. It’s a little like adding dried herbs at the beginning of making a stew: they’re creating a base layer of flavour. If you’re looking at a bottle or can, you might see the label “IBU.” International Bitterness Units are a measure of how bitter something is, and 100 is the top end of the scale for human perception.

Over the last decade, brewers have shied away from bitterness, choosing instead to accentuate the essential oils in hops. And now they’re looking for aromatic properties, which is like finishing a dish with fresh herbs for an enhanced sensory experience. The myrcene and humulene that make up the essential oils in hop cones tend to break down into recognizable scents that have chemical commonality with herbs, spices, and citrus and tropical fruits. In pairing, this is typically a secondary consideration, but these aromatic compounds can also fill out a flavour profile if deployed properly.

Let’s revisit the fish and chips from earlier. How are you going to dress that? We know that there’s going to be a commonality with Pale Ale from the malt and cooking process. If it’s an English Pale Ale, the beer is going to be moderately bitter and probably use English hops, which means the aromas will be herbal and floral, with a hint of hedgerow and citrus. Let’s borrow some mayonnaise from the Belgians across the channel and load it up with thyme and tarragon.

You’ve matched the fried elements of the dish with malt depth, the beer is probably just acidic and bitter enough to cut some of the fat, and bubbly enough to lift it off the palate.  Above that, you’ve got interplay between the herbs and hops, creating a fuller flavour profile beyond basic considerations.

You want something lighter? Ditch the chips and throw that fish in a griddled tortilla with some red onion, slaw, guacamole and a little jalapeno. The modern American Pale Ale has a lighter malt character and an entirely different set of aromas. Citrus, stone fruit and tropical characters are there waiting to play. The carbonation is still going to lift the guac and fried fish from the palate, but the bitterness will make the red onion seem sweeter, and the hops will make the pyrazine in the pepper seem peachy.

Esters and Phenols

Some of the by-products of fermentation are aromatic esters and phenols. Esters are fruity and, depending on the yeast you’re using, you can get banana, red apple, pear or even pineapple. Phenols are spicy, and occur mostly in Belgian and German ales. You might get clove, allspice, vanilla or bubblegum aromas. In a yeast-driven beer like a Hefeweizen or an Abbey-style Ale, they’re going to be right up front.

Let’s see if we can put all of this together with something really complex: Chicken Korma. There’s a lot going on: the protein is light, but the sauce is anything but. There’s coconut milk and a plethora of spices, including garam masala, curry powder, coriander, cinnamon, cardamom and cumin. So, you need something that can stand up to the intensity of the dish.

I would go with Belgium’s De Ranke XX Bitter. It has everything you need in a pairing functionally and flavourfully. The bright carbonation will lift that coconut milk and refresh between bites, while the Belgian yeast character will complement and flesh out the variety of spices in the curry even as the bitterness cuts the sweetness on the palate. Both the beer and the dish will make the other more complete, providing a purpose for each element and a better experience for the diner.