The ultimate, moist chicken for your next Sunday roast

If you want an epic Sunday roast, then look no further than this juicy buttermilk roast chicken.

  • SERVES: 4
  • PREP TIME: 5 mins
  • COOK TIME:  60 mins
  • DIFFICULTY: easy

What is In buttermilk?

You may be thinking, what is buttermilk?

Or why would I want to make my own buttermilk?

Or even, how would I use buttermilk?

I was late to the buttermilk party.

I only ever came across it if I was in the US for work.

And ordered buttermilk pancakes (delicious, btw).

But then I discovered Samin Nosrat.

And her Buttermilk Roast Chicken.

What a game-changer to the Sunday roast.

But buttermilk isn’t always the easiest to find.

So, I found out how to make it at home.

And it turns out, it’s easy.

But first…

What is buttermilk?

Ok, first of all, it doesn’t contain butter.

The traditional buttermilk was the liquid leftover after whole milk has been churned into butter.

Nowadays, it’s a cultured, fermented dairy product.

It contains bacteria that make it sour and thicker than regular milk.

Juicy buttermilk roast chicken

What does buttermilk do to chicken?

A buttermilk brine tenderises the chicken while keeping it moist.

The acid in buttermilk penetrates deep into your chicken.

And this is what makes your roast super tasty and juicy.

It’s best to marinate your chicken in buttermilk overnight if poss.

Or at least 1 – 2 hours.

When you’re ready to cook your chicken, remove it from the bag, and scrape off the excess buttermilk (no need to be overly fussing).

And pop it in the oven.

The only thing I’d add, is you need to occasionally move the bird around in the oven to prevent the buttermilk from catching.

It will go dark quite quickly compared to a normal roast chicken.

Buttermilk roast chicken

Store-bought vs homemade buttermilk

Store-bought buttermilk is thicker, tangier, and more acidic.

Homemade buttermilk is thinner and slightly sweet tasting.

So, it could give a different taste to your baked goods if you use homemade as it is less acidic than bought.

Buttermilk substitute

Acidified milk

Add one tablespoon of lemon juice or white vinegar to a liquid measuring cup, and add enough milk until it measures 1 cup.

Stir, and let sit for five minutes before using.

Watered-down yoghurt

Whisk a bit of milk or water into plain, unsweetened yoghurt until you get a buttermilk-like consistency.

The proportion will depend on the thickness of your yoghurt, but generally, it’ll be around 1/4 liquid with 3/4 cup yoghurt. (Only have Greek yoghurt? You’ll need a little extra water to thin it out.)


Substitute equal parts kefir for buttermilk in any recipe—just make sure it’s unsweetened, unflavored kefir. 

Watered-Down Sour Cream

Whisk together equal parts sour cream and water

Reference: Epicurious

How to make your own buttermilk substitute

I found this little recipe from BBC Good Food

And all you need is whole milk and white vinegar, or lemon juice.


  • 250ml whole or semi-skimmed milk
  • 1 tbsp lemon juice or vinegar


  • Mix the milk and lemon juice in a jug. 
  • Leave at room temperature for 5-10 mins until the milk has thickened slightly.
  • It won’t thicken as much as traditional buttermilk, but it’s a great substitute when making scones, soda bread or pancakes.
  • Don’t worry if the mixture looks curdled or has small white lumps in it, it will be fine once cooked. 

Other uses for buttermilk

It’s used mainly for baking.

But you’ll see it used in things like:

  • Biscuits
  • Cornbread
  • Pancakes and waffles
  • Poundcake
  • Marinade for fried chicken
  • Smoothies and milkshakes
  • Mashed potatoes or grits
  • Instead of coconut milk or cream in curries and soups
  • Chocolate cake
  • Muffins
  • Creamy salad dressing

And as I mentioned, use it to marinate a whole chicken.

And you’ll be appointed Head of Sunday Roast every week.

You can freeze it

Buttermilk freezes well.

Best way to freeze it is in measurements you might often use e.g. freeze it in 1 cup measures.

Looking for other roast chicken ideas?

Check out another favourite, Jonathon Waxman’s roasted chicken with salsa verde

Recipe: Salt, Fat, Acid and Heat

Buttermilk roast chicken

Course Main Course
Keyword buttermilk roast chicken, roast chicken, sunday lunch, sunday roast
Prep Time 10 minutes
Cook Time 50 minutes
Overnight marinading 1 day
Total Time 1 day 1 hour
Servings 4 people
Cost £


  • 1.5 kg high welfare chicken
  • 2 cups buttermilk
  • sea salt


Overnight marinade

  • Remove the wingtips (or be prepared to put tin foil around them when roasting as they can burn quite quickly)
  • Season the chicken generously with sea salt and let sit for 30 mins
  • In a bowl, add the 2 cups of buttermilk and 2 tbsps of sea salt and mix together.
    Place the chicken into a large sealable plastic bag and pour in the buttermilk. Seal the bag, then squish the buttermilk around so it covers the whole chicken.
    Put on a plate and pop into the fridge for 24 hrs.

Roasting day

  • Take the chicken out of the fridge an hour before cooking so it comes to room temperature.
    Preheat the oven to 220C/425F.
  • Take the chicken out of the bag and scrape off the buttermilk but don't get obsessive about it. Tie its legs together.
  • Place in a roasting tray and put into the centre of the oven. It's best to have the legs pointing into one corner of the oven as this is usually the hottest area so you won't dry out your breast first.
  • After approx 20 mins, the chicken will start to brown so reduce the heat to 200C/400F and cook for another 10 mins, then move the roasting tray so the legs face the other corner of the oven.
  • Cook for another 30 mins or so, until the chicken is brown all over and the juices run clear (or use a meat thermometer to reach 74 C).
    Once cooked, remove and rest for 10 mins on a platter before serving.


Recipe: Samir Norsat