A milkshake stout is a dark beer that borrows the idea of a milkshake IPA, which means it is built on oats and lactose and then loaded with something sweet and strongly flavoured, and the trend arrived in British Columbia and across Canada by way of an American craft wave of hazy IPAs rather than from any old milk stout tradition. Whether it works is a fair question, because the technique behind the name is real, since lactose and milk solids genuinely change the body and the foam of a beer, but the dessert toppings are decoration rather than brewing. The honest split is this. The base of oats and lactose is a legitimate technique that produces a genuinely different beer, and the vanilla, fruit and brownie additions are a marketing decision that can either suit the beer or bury it.
The Name Is Recent, The Milk Is Not
It is worth separating two things that share a word. English milk stout is an old style, going back centuries, and it was made with lactose added to a dark ale, traditionally as a cheap source of body and sweetness. That is a genuinely historical style with a real brewing logic to it, and the breweries that revived it in the modern era were reviving something with roots, not inventing something new. The milkshake stout is a different animal entirely, because it takes the American hazy IPA craze, which spread through craft beer in the 2010s, and applies its oat and lactose and dessert logic to a dark beer instead of a pale one. Our post on hazy IPAs covers where that craze came from, and the milkshake stout is a spinoff of it rather than a branch of milk stout.
So when you see a milkshake stout on a shelf, the useful question is not whether milk stouts are traditional, because the dessert versions are not. The question is whether the brewer is doing something with the oats, the lactose and the base beer, or simply pouring syrup and powder into a stout and calling it a milkshake.
What Lactose And Oats Actually Do To A Dark Beer
Lactose is the sugar in milk, and it is the single ingredient that makes a milkshake beer a milkshake beer. Brewer's yeast cannot ferment lactose, so unlike cane sugar or malt sugar, it does not feed the yeast and does not make the finished beer stronger. It simply stays in the beer, and because it is a sugar, it makes the beer sweeter and rounder. That is the whole trick. A brewer who wants a sweet dark beer can add lactose after fermentation, when the yeast is done, and the result is a stable sweetness that does not fade. The same principle is why lactose is the base of the dessert style rather than any roasted malt trick, because roasted malt gives roast and bitterness, not sugar.
The oats do a different job. Oats contain a high proportion of beta-glucan, a long-chain soluble fibre that increases the viscosity of the liquid, so an oat-heavy beer feels thicker and more coating on the tongue than a beer built only on barley. Oats also add a creamy, almost dairy-adjacent quality to the aroma and the foam, and they help a head that is soft and pillowy rather than thin and brittle. Milk proteins, if a brewer adds milk or whey rather than just lactose, do a similar thing, because proteins and sugars both stabilize foam. So a milkshake stout is, in technical terms, a dark beer made creamy and sweet by dairy components, and everything else is flavouring on top.
The Dessert Toppings, And What They Cost You
This is where the gimmick and the technique part company. Vanilla, fruit purée, cocoa powder, brownie dough, marshmallow and the rest are additions that change the aroma but do not improve the beer underneath. Vanilla is the most forgiving, because it sits alongside chocolate and roast and reads as dessert rather than as an additive. Fruit purées can work when the fruit matches the roast, so a raspberry stout is a real combination rather than a novelty. But when a beer smells of artificial strawberry and tastes of sweetener more than of malt, the additions have buried the base, and that is the honest criticism of the trend. The drinkers who enjoy these beers are not being fooled, they genuinely want a beer that tastes like a dessert, and there is nothing wrong with that as a want. The problem is only when a brewery charges premium money for a stout and hands you syrup instead of a well made dark beer.
There is one more thing about the additions worth knowing. Because lactose is already sweet, a beer that is both heavily dosed with lactose and heavily flavoured can be cloying, and cloying is the failure mode of the whole style. A beer that is merely sweet is a dessert beer, but a beer that is sweet and thin, with no roast or bitterness to give the sweetness somewhere to sit, is just sweet. A well made milkshake stout keeps a dark, roasted, slightly bitter backbone under the sweetness, and that backbone is what stops it from tasting like a milkshake syrup poured into a glass.
Where It Sits Against A Plain Stout
| What changes | A plain stout | A milkshake stout |
|---|---|---|
| Body | Medium to heavy, driven by roasted malt | Heavier and creamier, driven by oats and dairy |
| Sweetness | Low, with roast and bitterness in front | Noticeably sweet, with lactose as the source |
| Foam | Firm, sometimes rocky for a nitro pour | Soft, pillowy and stable, helped by protein and sugar |
| Aroma | Roast, coffee, chocolate, dark fruit | Roast plus vanilla, fruit, cocoa or dessert |
| Alcohol | Often higher, since sugar is used for strength | Usually not higher, because lactose is unfermentable |
| Best after | Roast and barrel character | Freshness, since the dairy and fruit fade quickly |
The alcohol line in that table is the one people get wrong. Because lactose cannot be fermented, adding it does not make a milkshake stout stronger, and a brewer who wanted to make it stronger would add cane sugar or malt sugar alongside it. So a milkshake stout can be a session strength, an imperial strength, or anything in between, and the sweetness on your tongue tells you nothing at all about the alcohol in it. This is worth flagging because a sweet, low-alcohol-tasting dessert beer can catch people out on a night when they are not counting drinks, and nothing in the sweetness of a milkshake stout warns you that it is stronger than it tastes. Read the percentage, as you would for any beer.
Dietary Facts Worth Getting Right
A milkshake stout contains dairy, so it is not a vegan beer, and a brewer who markets it as a dessert should be clear about the milk. It is also, unless a brewery specifically states otherwise, a barley beer, and barley contains gluten, so it is not suitable for a person with coeliac disease. Adding lactose does not make a beer gluten free. The vegan and gluten free approaches are covered in our post on brewing for special diets, and the short version is that both require a brewery to say so on the label, because you cannot tell from the style or the name.
How To Buy One Worth Drinking
- Read the alcohol by volume, since the sweetness gives no clue and these beers range from session strength to genuinely strong.
- Check the ingredient list if one is printed, and look for actual lactose or milk rather than only flavouring, since that is what tells you the technique is there.
- Pour it into a glass that is not ice cold, because a very cold milkshake stout tastes of nothing but cold and sugar.
- Look for a roasted backbone in the aroma under the dessert notes, since that is the difference between a dessert beer and a syrup.
- Buy it fresh. Dairy and fruit flavours fade quickly, and unlike a barrel aged stout, a milkshake stout does not improve with time in the bottle.
So Does It Work
The technique underneath it works, and it works well. Oats and lactose are a clean, well understood way to make a dark beer creamier, sweeter and better foamed than a stout brewed only on roasted barley, and a brewer who does that and leaves the roast as the backbone has made a genuinely interesting beer. The dessert framing is where the disagreement sits, because it invites people to judge the beer as a milkshake rather than as a beer, and a milkshake is judged on sugar. If you are a beer drinker and want roast and depth, drink a good plain stout. If you want a dark beer that is soft, sweet and dessert-like, the milkshake stout is a fine way to get there, and you should not feel any need to apologize for it. What is not fine is paying for a thick, syrupy, one dimensional beer with a chocolate bar graphic on the label, which is the version of this trend that gave the style its bad name.
