Homemade Guinness Mustard - Irish Beer Mustard Recipe

Modified: Feb 16, 2026 · Published: Mar 12, 2017 by Analida · • Word count:1429 words. • About 8 minutes to read this article. • This post may contain affiliate links ·

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Guinness isn't just for sipping - it makes an incredible condiment too. This homemade Guinness mustard recipe combines whole mustard seeds with rich stout beer to create a bold, tangy beer mustard that's perfect for brats, burgers, sandwiches, and Irish favorites. Easy to make and packed with deep, malty flavor, this whole grain mustard is far better than anything from the store.

a can of guinness and a bowl of mustard with a spoon scooping mustard

Jump to:

Why This Guinness Mustard Is The Best
The Science Behind Homemade Mustard
Mustard: One of Europe's Oldest Native Spices
Where Do I Get Bulk Mustard Seeds?
Top Tips for Great Guinness Mustard
What to serve with Guinness mustard?
Interesting Facts About Guinness and Mustard
Frequently Asked Questions
📖 Recipe

Why This Guinness Mustard Is The Best

This homemade whole grain mustard combines the deep roasted character of Guinness stout with tangy mustard seeds to create a uniquely bold condiment you won't find in stores. While gourmet mustards are available everywhere, making your own at home lets you control the flavor, heat, and sweetness - and it's easier than you think.

I never in a million years thought I would be making my own whole grain mustard, let alone this Guinness recipe, because most well-stocked grocery stores offer a large selection of gourmet mustards. I also thought that the process required special equipment. A few months ago, while reading a food magazine, inspiration struck.

a bowl of mustard and a spoon with a tray of sausages in the back

The Science Behind Homemade Mustard

Making homemade mustard feels a little like a kitchen science experiment - and in many ways, it is.

Mustard seeds contain natural compounds and an enzyme called myrosinase. When the seeds are crushed and mixed with liquid, a chemical reaction occurs, creating mustard's signature heat and sharp flavor. The temperature of that liquid directly affects how strong your mustard becomes.

Cold liquid (like chilled Guinness or vinegar) slows the reaction but preserves the enzyme, producing a shaper, spicier, more pungent mustard.
Warmer or hot liquid partially deactivates the enzyme, resulting in a milder, smoother, more mellow flavor.

So if you love bold, sinus-clearing heat, start cold. Prefer a gentler, deli-style mustard? Use lukewarm liquid instead.

a fork with guinness mustard with a bowl of mustard, sausages, and guinness in the back

Mustard: One of Europe's Oldest Native Spices

Mustard is one of the few spices native to Europe, and it has flavored food for thousands of years. Ancient Greeks and Egyptians used mustard seeds to season their dishes, while the Romans fully embraced its bold heat. In fact, their Latin name for mustard - mustum ardens, meaning "burning must" - perfectly captures its sharp bite. The Romans were also early innovators, mixing crushed seeds with fresh grape juice (verjus) to create a paste that closely resembled the mustard we know today.

From there, mustard spread across Spain and Gaul, becoming so popular in medieval France that spice merchants classified it as épices d'enfer - "spices from Hell" - a nod to its fiery kick. Although often associated with European cooking, mustard has also been cultivated in China for over 2,500 years.

Now that you know how to make Guinness mustard, you can start experimenting with other liquids too - maybe champagne or cider next? Just remember to let your homemade mustard rest for two or three days before serving so the flavors mellow and develop.

Where Do I Get Bulk Mustard Seeds?

If you want to make a big batch of this mustard you can buy bulk brown mustard seeds and bulk yellow mustard seeds on Amazon. (Affiliate links.) You can also click to adjust the servings in the recipe below. I have seen mustard seeds sold in five pound bags online. This will make a lot of mustard!

Top Tips for Great Guinness Mustard

Making homemade Guinness mustard is easy, but a few small tricks make a big difference in flavor and texture.

Start cold for bold flavor: Use cold Guinness and vinegar if you want a sharper, spicier mustard. Cold liquid preserves the natural heat from the mustard seeds.
Soak longer for better texture: Let the seeds soak at least 24-36 hours. This softens them fully and helps create that creamy, spreadable consistency.
Blend to your style: Pulse briefly for a coarse, whole-grain mustard or blend longer for a smoother, deli-style spread.
Taste and adjust sweetness: After blending, add a touch more honey or brown sugar if you prefer a sweeter balance to the stout's bitterness.
Let it mellow: Fresh mustard can taste harsh at first. Rest it in the fridge for 2-3 days to allow the flavors to round out and deepen.
Store properly: Keep your Guinness mustard in airtight glass jars in the refrigerator. Thanks to the vinegar and beer, it will stay fresh for months.

What to serve with Guinness mustard?

This Guinness mustard pairs beautifully with hearty Irish comfort foods. Serve it alongside Dublin Coddle, where its tangy kick balances the rich sausages and potatoes, or spread it thick on warm slices of Irish brown bread for a simple, flavorful snack. It's also right at home next to a bowl of Guinness stew, where the malty stout flavors in both the stew and the mustard complement each other perfectly. Whether you're building a St. Patrick's Day spread or just craving cozy pub-style dishes, this homemade beer mustard brings everything together.

Interesting Facts About Guinness and Mustard

Guinness was first brewed in 1759: Arthur Guinness signed a 9,000-year lease at St. James's Gate Brewery in Dublin. The roasted barley used in Guinness gives it the deep coffee-like flavor that makes it ideal for bold condiments like mustard.
Whole grain mustard is the traditional European style: Unlike smooth yellow mustard, whole grain mustard preserves the texture of the seeds. This gives it a more complex flavor and makes it especially popular in France, Germany, and Ireland.
Dark beers work especially well for mustard: Stouts and porters contain roasted barley, which adds deep, slightly bitter, chocolate-like notes. This balances the acidity of vinegar and enhances the overall flavor.
Mustard is naturally preservative: Because of its acidity and natural antimicrobial compounds, homemade mustard can last for months in the refrigerator without spoiling.
Guinness mustard is a traditional pub condiment: Beer mustards are commonly served in Irish and British pubs alongside sausages, pork pies, and cheese boards.
You can customize mustard endlessly: Different liquids create different flavors. Try using hard cider, whiskey, champagne, or even apple juice to create unique variations.

Frequently Asked Questions

What does Guinness mustard taste like?

Guinness mustard has a bold, tangy flavor with deep malty notes from the stout. It's slightly sweet, mildly bitter, and more complex than classic yellow mustard - perfect for sausages, burgers, and sandwiches.

Why is my homemade mustard so spicy?

Fresh mustard can taste extra sharp at first, even bitter. Crushing the seeds releases natural compounds that create heat. Let your Guinness mustard rest in the fridge for 2-3 days to mellow and smooth out the flavor.

Does liquid temperature really affect mustard strength?

Yes. Cold liquid produces a stronger, spicier mustard, while warm or hot liquid creates a milder, smoother flavor because heat reduces the enzyme reaction that creates mustard's kick.

How long does homemade Guinness mustard last?

Stored in an airtight jar in the refrigerator, homemade mustard can last 2-3 months or longer. The vinegar and beer help naturally preserve it.

Can I use a different beer instead of Guinness?

Absolutely. Try another stout, porter, or even a brown ale. Each beer adds a slightly different flavor profile, so it's fun to experiment.

What foods pair best with Guinness mustard?

It's delicious with brats, corned beef, roast beef sandwiches, burgers, pretzels, charcuterie boards, and Irish pub-style dishes like soda bread or stew.

Does Guinness mustard contain alcohol?

Yes - because this recipe isn't cooked, some alcohol from the Guinness will remain in the finished mustard. The amount may lessen slightly as it sits (a little can evaporate over time), but it won't fully disappear. If you need an alcohol-free option, use non-alcoholic stout or replace the beer with extra vinegar/water (the flavor will be different, but still tasty).

📖 Recipe