Make the perfect sourdough

Jo and Chris Brennan from the award-winning Pump Street Bakery share their secret to making the most delicious sourdough loaf.

Fermentation is all the rage these days. From sourdough bread, to home brews, kimchi, sauerkraut, kefir and the fermented tea drink kombucha, using the action of microorganisms to help us make food is a millennia-old tradition that is undergoing a revival in restaurants and in home cooking.

Fermentation involves the conversion of carbohydrates to alcohol, carbon dioxide and acids using yeasts and bacteria. As a bakery, we have built our business on the action of yeast to make bread, so fermentation is very important to us as we wouldn’t have any bread without it. We specialise in sourdough; a bread made with a mixture of yeast and bacteria that, through fermentation, make our bread rise and give it flavour.

In order to make sourdough bread you need to make a sourdough starter, which you then feed regularly to keep the yeast and bacteria alive and multiplying. You then use small amounts of the starter when you make bread. Making a sourdough starter at home is very easy, and inexpensive, but does take time and attention to detail.

When creating a sourdough starter, you are making a mixture of flour and water in which you are encouraging a single pair of one yeast and one bacteria to live harmoniously. The yeast produces carbon dioxide as it eats through the flour, which makes the bread rise, and the bacteria produces acids that give the dough its distinctive sourdough tang. It’s a symbiotic relationship – these wild yeast thrive in an acidic environment, so they like the lactic and acetic acids produced by the bacteria, and the bacteria helps break down the sugars for the yeast to eat.

We recommend using pineapple juice in place of water for the first couple of days; this idea of Debra Wink’s (via is a brilliant solution to the problem of fast-multiplying, unwanted bacteria that can takeover at the beginning, overwhelming the good yeast and bacteria. The pineapple juice reduces the pH of the mixture and inhibits the unwanted bacteria, leaving time for the good ones to grow. It’s also fine to use water from the beginning, but there is a chance that the unwanted bacteria will overtake your culture.

Recipe: How to create a sourdough starter

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Pineapple juice

Organic whole wheat, whole rye or white bread flour


NB: Use any of the flour types or a mix of flours.

Day 1: In a small bowl, mix 100g flour with 100g canned pineapple juice (at room temperature) until it is a thick paste. Scrape mixture into a bowl or plastic container, cover with cling film. Leave at room temperature for 24 hours

Day 2: You probably won’t notice much change at this point. Scrape a half of the contents of the jar into a mixing bowl and add 100g of whole wheat or whole rye flour plus 100g pineapple juice (make sure juice is room temperature). Mix until all ingredients are evenly distributed. Wash and dry your container and scrape the mixture back in. Cover the container just like day one. Let sit at room temperature for 24 hours.

Day 3 : You may notice some activity at this point. The mixture may have risen some and there might be bubbles. Take 100g of the mixture (discard the rest), add 100g of flour, 100 g of water (no more pineapple juice!). Mix until evenly distributed. Cover and store as before.

Day 4: The mixture should have at least doubled in size at this point. If it seems to be sluggish and hasn’t doubled in size, then you should go back and repeat the Day 3 step. Otherwise feed the starter (take 100g starter, mix with 100g flour and 100g water, discard the rest) first thing in the morning and then again in the evening (about 12 hours apart).

Day 5: If your starter has been very active and always doubles in size (or more) between feedings, then it is ready to use. You may also choose to refrigerate your starter at this point and slow down the feedings to once a week. If you’d like to bake some bread, you can start now. (If your starter still seems a little sluggish, continue with the twice daily feedings as at Day 4.)

Maintenance: Once you have a robust starter, you won’t have to keep feeding it twice a day. You can safely store your starter in the refrigerator, where it will slow down then basically go dormant. It is recommended to take it out and feed it once a week to keep it healthy, especially if it is a newly established starter. You can also freeze small amounts and bring it back to life by defrosting and feeding twice a day until it is fully active.

Recipe: Sourdough loaf


250g of your sourdough starter

375g strong white bread flour or a mixture of bread flours

1tsp Maldon salt

Up to 175ml hand warm water


1. Mix the flour, sourdough starter and salt together then gradually add enough water to make a soft dough that’s not too sticky.

2. Rub oil onto a worksurface and tip out your dough, kneading until it feels smooth and elastic.

3. Put the dough in a bowl and cover with a carrier bag or clingfilm, leaving in a warm place to double in size – this can take a few hours longer than a bread made with commercial quick action yeast.

4. Knead the risen bread until smooth then shape and leave in a warm place again to prove.

5. Pre-heat your oven to 220C then place a tray of water in the bottom to create steam, which will give your bread a nice crispy crust. Cook the bread for 25 minutes then reduce the heat to 200C and cook for another 15 to 20 minutes. It should look golden and should sound hollow when you tap it on the base.

Q: What should my sourdough starter smell like and how can I tell it’s off?

A: Your sourdough starter should smell yeasty, but not unpleasant. It is unlikely to go off, but it might get what we call “the dreaded hooch”. If neglected, the yeast and bacteria will exhaust the available carbohydrates in the flour and will go dormant, causing a layer of brown clear liquid to form and the mixture to smell off and very acidic. However, usually it can be revived with a course of twice daily feedings until it returns to doubling in size.

New treat from Pump Street

Pump Street Bakery has just launched its incredible new bean to bar chocolate bar – Sourdough and Sea Salt.

Crafted using Venezuelan cocoa from Patanemo, the dark, smooth 66% cocoa bar has added Maldon sea salt and sourdough breadcrumbs from the Pump Street kitchen.

Lightly fruity, deep and rich and with a really pleasing crunch, this is a local product for chocolate lovers to savour.

Find the bar at Pump Street Bakery in Orford, Baker and Barista in Ipswich, Fresh Food Pantry, Snape, Green Olive Deli and Wild Strawberry Cafe in Woodbridge, Lawson’s Delicatessen in Aldeburgh. It’s also available online at