Ultimate Guide to Porter and Stout: Discovering the Differences & Brewing the Perfect Porter Recipe

The short answer: the line is blurry. Stout began in 18th-century London as a stronger (“stout”) porter. Today stouts usually get a sharper, coffee-like roast from roasted barley, while porters lean on chocolate and brown malts for a softer chocolate and caramel character. Stouts also tend to be a little fuller, but plenty of porters and stouts overlap.

	Porter	Stout
Origin	London, early 1700s	London, as a stronger porter; Dublin made it famous
Typical roast	Chocolate and brown malt	Roasted barley
Flavour	Chocolate, caramel, softer roast	Coffee, sharper roast; drier (Irish) or sweeter (milk)
Colour	Brown to black	Black
Common styles	English, American, Baltic porter	Irish, sweet (milk), oatmeal, imperial stout

A short history

Porter was the everyday beer of 1700s London, named for the street and river porters who drank it. Brewers made stronger versions and sold them as “stout porter”, and over time the name shortened to stout. Guinness in Dublin switched to porter in the late 1700s, and its stronger stout porter grew into the dry Irish stout most people picture today. Porter faded in Britain in the 20th century and came back with the craft beer revival.

Styles side by side

Style	Original gravity	ABV	What sets it apart
English porter	1.040–1.052	4.0–5.4%	Chocolate, caramel and toffee; gentle roast
American porter	1.050–1.070	4.8–6.5%	Stronger roast, more hops
Baltic porter	1.060–1.090	6.5–9.5%	Strong, smooth, usually lager-fermented
Irish stout	1.036–1.044	4.0–4.5%	Dry, roasted barley, often on nitro
Sweet (milk) stout	1.044–1.060	4.0–6.0%	Lactose adds body and sweetness
Oatmeal stout	1.045–1.065	4.2–5.9%	Oats give a silky body
Imperial stout	1.075–1.115	8.0–12.0%	Big, rich, dark fruit and roast

How the grain bill makes the difference

• Roasted barley is unmalted and roasted very dark. It gives the sharp, dry, coffee-like bite of an Irish stout.
• Chocolate and brown malts give a rounder cocoa and toast flavour, the backbone of most porters.
• Black (patent) malt adds colour and a burnt edge; use it sparingly.
• Dehusked roasted malts give colour and roast with less bitterness, handy for smooth porters and schwarzbier.
• Crystal malt, oats and lactose add body and sweetness, the difference between a dry and a sweet or oatmeal stout.

Most porters and stouts use only about 5–10% dark grain. More than that, and the roast turns acrid.

Christmas porter recipe

A simple, strong porter for the holidays, about 6 gal (23 L) into the fermenter.

Ingredient	Amount	Share
Pilsner malt	14 lb (6.35 kg)	91%
Black patent malt	12 oz (340 g)	5%
Crystal 60L	9 oz (255 g)	4%
Magnum hops, 60 min	0.85 oz (24 g)
Yeast	1 pack SafAle S-04

Mash at 156°F (69°C) for 60 minutes, then mash out at 168°F (76°C) for 10 minutes. Target about 6.2% ABV. The high mash temperature keeps plenty of body to carry the roast.

Want more? Our tested recipes scale from 5 to 30 gallons: English porter, robust porter, Baltic porter, Irish stout and oatmeal stout.

Frequently asked questions

Is Guinness a porter or a stout?

A stout: a dry Irish stout. Guinness also brewed porter for most of its history.

Which is stronger, porter or stout?

Historically stout, since it was the stronger porter. Today it depends on the style: an Irish stout is often weaker than an American or Baltic porter.

Why is my stout harsh or acrid?

Usually too much black malt or roasted barley, or a mash pH that’s too low from all the dark grain. Keep dark grain under about 10% and check your water: see our guide to mash pH.

Is a Baltic porter a lager?

Usually. Most are fermented cool with lager yeast, which gives a smooth, clean finish.

Related guides

The history of stout, how roasted malts change flavour, choosing brewing malts and all our recipes.