– Ready to use in 7 to 9 days –
Gather together…
* Pyrex 0.5 litre (toughened) glass bowl (I have two of these bowls, one to use and one at the ready) - Amazon sells these 0.5 litre Pyrex lidded bowls. I REALLY would suggest buying two bowls. You'll need the plastic lid(s) when you are storing your hibernating starter in the fridge.
* a clean, dry, cotton cloth to cover the Pyrex bowl with, secured with an elastic band.
* Wholemeal brown flour / Rye flour (I use Allinsons Very Strong Wholemeal Bread Flour, as that's what I can get via online supermarket shopping).
* Pineapple juice from a large tin of pineapple chunks / rings, labelled as being 'in juice' not syrup, (supermarket own brand is fine).
*A metal spoon (for stirring).
*Set of measuring cups / electronic scales - I have given the amounts to add in both volume (cups) and mass/weight (grams) as different people have different equipment available. When 1/6 of a cup volume is mentioned, It means that I just fill a 1/3 cup halfway.
* A clean damp cloth.
* Sign to stick on oven door (so no one accidentally frazzles the warm yeast).
Get making…
1. On Day#1, ensure your 0.5 litre Pyrex (toughened glass) bowl is clean. I used to use a Mason jar or a household glass jar but three times these cracked! (1 cracked Mason jar and two cracked regular jam jars - eek, my starter "Mary" had a narrow escape each time.) You do have to scrub the container pretty hard to get the dried on starter to clean off... I also no longer use a Tupperware container for my starter, since reading that plastic can react with the yeast by-products .
2. Put 2 tbsp (24g) of wholemeal brown flour into the bowl. Wholemeal flour (especially rye flour apparently) contains more protein than white flour, so it helps to power your sourdough starter for longer.
3. Put 2 tbsp (30g or 30ml) of the tinned pineapple juice into the bowl. Pineapple juice is acidic which encourages a low-pH in the bowl right from the start, this helps to establish the right type of micro-organism much more quickly than using water. If you did just use water, the bacteria that initially grow do eventually cause a drop in pH, which kills them off and allows the yeast that we want to grow to thrive, but it would take a few days longer to happen. Most people become disheartened and give up before that point, fearing they have 'killed' the yeast (when actually they just haven't given them chance to establish as the dominant species yet).
4. Stir well to combine the flour and pineapple juice, but try not to splash too much up the side of the bowl. Any splashes need wiping off with a clean, damp cloth (not the usual kitchen cloth, a fresh cloth!) as splashes up the side encourage aerobic (oxygen loving) bacteria to grow, which compete with the yeast you are trying to cultivate.
5. Place a clean, dry cotton cloth on the top of the jar and secure it with an elastic band, this is to keep insects, air-borne germs and dirt out, but it allows gases to be able to pass in and out of the fermenting mixture.
6. Place your cloth-covered bowl in the oven (yes, in the oven!) but with ONLY the oven light turned on. If it is a COLD DAY then pre-warm your EMPTY oven for 1 minute at 180 C ish - set a timer for 60 seconds or it will get too warm, before turning the heat OFF and just leaving the oven light ON. The slight heat from the oven bulb keeps the jar at just the right temperature, day and night. Put a note on the outside of the oven so that no one unwittingly turns on the oven to pre-heat it, as this would frazzle your yeast into oblivion - arrgh! When the oven is in use (as an oven and not just as a yeast incubator), put your bowl somewhere warm but not too warm, not in direct sun and not in a draft - the yeast is quite particular.
7. On Day#2 (at the same time as you fed it yesterday) add 2 tbsp more of the wholemeal flour and 2 tbsp more of pineapple juice to the bowl and stir. Again, wipe away any splashes and cover the bowl with the cloth again. Keep the bowl warm using the oven light bulb method. If it is a COLD DAY then pre-warm your EMPTY oven for 1 minute at 180 C ish - set a timer for 60 seconds or it will get too warm, before turning the heat OFF and just leaving the oven light ON.
8. On Day#3 (at the same time as you fed it yesterday) add 2 tbsp more of the wholemeal flour and 2 tbsp more of pineapple juice to the bowl and stir. Again, wipe away any splashes and cover the bowl with the cloth again. Keep the bowl warm using the oven light bulb method. If it is a COLD DAY then pre-warm your EMPTY oven for 1 minute at 180 C ish - set a timer for 60 seconds or it will get too warm, before turning the heat OFF and just leaving the oven light ON.
9. On Day#2 and Day#3 you may see a few bubbles, this won't be the active yeast yet, it will be other bacteria thriving - they will be out-competed shortly by the yeast which favour the acidic conditions created by the juice. So the bowl won't smell of yeast yet, this is normal and shouldn't worry you.
10. On Day#4 you need to start feeding the yeast generously - at this stage it becomes important that you are giving it the right amount of food. However much sourdough starter you have left in the bowl, that's the amount you need to feed, in terms of both flour and water. This is why you need to 'discard' quite a lot of sourdough starter before every feed, or else you have to add ever-more flour each time and that is a waste. At this point you need to bin the 'discard' you remove, as it isn't yet mature. Once your starter is established, any 'discard' can be saved and put to good use - more about that later.
11. So, on Day#4 (at the same time as you fed it yesterday), measure out 1/6 of a cup (40g) of the fledgling sourdough starter (which you will keep) and bin the rest. You don't need a special 1/6 size of cup, just HALF FILL your 1/3 cup measure. N.B. Put the unwanted (immature) discard straight into the outside bin, or else your kitchen bin will start to smell.
12. Clean out the pyrex bowl really well with hot water (or if you have two jars to use in rotation, then put the dirty one to soak and begin to use the fresh bowl). If you are using a bowl straight after cleaning it, then please do allow the bowl to cool slightly (you don't want to kill the yeast with a too-hot surface).
13. Tip the 1/6 cup (40g) of fledgling sourdough starter into the clean bowl and then add 1/6 cup (40g) of lukewarm water (NOT pineapple juice any longer), stir to loosen and then add, 1/6 cup (20g) of the wholemeal flour. Stir well, wipe down any splashes, re-cover with the cotton cloth (maybe switch the original cloth for a fresh cloth at this stage) and replace the pyrex bowl back into the oven with just the light on. If it is a COLD DAY then pre-warm your EMPTY oven for 1 minute at 180 C ish - set a timer for 60 seconds or it will get too warm, before turning the heat OFF and just leaving the oven light ON.
14. On Day#5 do the same as you did on Day#4. At the same time as you fed it yesterday, remove and keep 1/6 cup (40g) of sourdough starter (discard the rest), wash the bowl well / swap the dirty bowl for a clean bowl. To the 1/6 cup (40g) of starter, add the lukewarm water (1/6 cup or 40g) and stir, then add the same volume of flour (1/6 cup or 20g) and stir well. Wipe down the pyrex sides, cover with the cloth and keep warm in the oven-with-just-the-light-on. If it is a COLD DAY then pre-warm your EMPTY oven for 1 minute at 180 C ish - set a timer for 60 seconds or it will get too warm, before turning the heat OFF and just leaving the oven light ON.
15. If your yeast cells are super-hungry (resulting in you accidentally under-feeding them), they will certainly let you know. Hungry yeast show it by producing a liquidy residue called 'hooch' which sits on top of (or sometimes sneakily as a mid layer within) the mixture in the bowl. This doesn't mean that you have killed your yeast - fear not! It means that the yeast cells are very much alive but very hungry. Read on to find out what to do if you find a hooch layer.
16. On Day#6 continue to feed your yeast once a day, just as you did on Day#5, unless you see the liquidy hooch layer. If you do find a layer of hooch on top of / within your starter, simply tip it away (I usually just stir hooch into an established batch of starter, but when forming a fledgling starter I tip it away), give the starter a good stir and from then on FEED TWICE A DAY, at intervals of 12 hours. So if you usually discard-then-feed your fledgling sourdough starter at 8pm, now also discard-then-feed it at 8am too.
17. On Day#7 you should have a happy sourdough starter, which you are probably discarding-then-feeding twice a day. You should see bubbles forming in the starter after each feed, showing the yeast are active. The sourdough starter will now have a pleasant beer-y, yeasty smell. To see how much rise your yeast will provide, check on it an hour or two after feeding, to see how far up the side the bubbles have got.
18. Although you could use the sourdough starter now (if it is bubbling well after feeding), I would continue to look after it in the usual way on Day#8 and Day#9 (keeping it warm and discarding-then-feeding twice a day, or even three times a day if your yeast shows signs of hunger by producing hooch) to really get the yeast active and happy. Now you can begin to SAVE THE DISCARD to use in 'sourdough discard' recipes, e.g. in delicious Sourdough-Discard Brownies. Put the discard into a securely-lidded container in the fridge and keep adding more discard to it (for up to two weeks) until you have enough to use in a 'sourdough discard' recipe - the brownie recipe mentioned above requires 200g of discard. Each time I bake using the discard, I get rid of any leftover discard and wash out the securely-lidded container and start collecting afresh.
19. Two hours before you intend to use some of the starter for baking, give it an extra feed, but this time feed it a little differently... Look at how much starter you need for the recipe. As an example; if you need 150g of starter to bake with, then discard less of the starter than usual, ensuring you have a 1/3 cup (80g) of starter left in the bowl. To that add a 1/3 cup (80g) of lukewarm water - stir well at this point to loosen the mixture - plus a 1/3 cup (40g) of wholemeal flour. Stir well and wipe down, cover loosely and put it to keep warm in the oven with just the light on. If it is a COLD DAY then pre-warm your EMPTY oven for 1 minute at 180 C ish - set a timer for 60 seconds or it will get too warm, before turning the heat OFF and just leaving the oven light ON. This means that you have almost 200g of starter (80g + 80g + 40g = 200g) in the bowl, and when (in a couple of hours time) you remove 150g to bake with, you'll still have some left (200g - 150g = 50g) in the bowl to continue looking after for future bakes.
20. If you are not intending to bake with your starter for 3+ days, then PUT THE PLASTIC LID ON TIGHTLY and put it in the back of the FRIDGE, after giving 1/6 cup (40g) of the starter a DRIER feed of 1/6 cup (20g) of flour plus just 1 tbsp (15g) of COLD water - we want the yeast in the starter to hibernate and we don't want to dilute the food source (flour) with too much water. Check your in-the-fridge starter every few days - if a hooch layer has accumulated on top then stir it into your starter and discard-and-feed with the DRIER feed quantities as above (with cold water) and return it to the back of the fridge.
21. When you want to use a fridge-stored sourdough for baking, FIRST THING IN THE MORNING THE DAY BEFORE BAKING DAY, remove the starter from the fridge, rehydrate it a bit by stirring in an extra 1/6 cup of warm water and then discard all but 1/6 of a cup and give it a normal feed (1/6 cup i.e. 40g of starter needs 1/6 of a cup i.e. 40g of warm water - stir well at this point to loosen - plus 1/6 of a cup i.e 20g of flour). Cover it with a clean cotton cloth, secured by an elastic band (so the re-activating yeast can 'breathe'). Discard-and-feed it like this whenever it looks hungry during the day (check every 3 hours for the presence of liquid 'hooch' which shows it is hungry - stir the hooch in and do a normal 'discard and feed'). Keep it in the oven (with just the oven light on) for warmth, to get the yeast back to an active state. If it is a COLD DAY then pre-warm your EMPTY oven for 1 minute at 180 C ish - set a timer for 60 seconds or it will get too warm, before turning the heat OFF and just leaving the oven light ON. Then two hours before you intend to use some of the starter for baking, give it an extra feed but this time feed it a little differently... Look at how much starter you need for the recipe. As an example, if you need 150g to bake with, then discard less of the starter than usual, ensuring you have a 1/2 cup (120g) of starter left in the bowl. To that add a 1/2 cup (120g) of lukewarm water - stir well at this point to loosen- plus a 1/2 cup (60g) of wholemeal flour. Stir well and wipe down, cover loosely and put it to keep warm in the oven with just the light on. This means that you have 1.5 cups of starter in the bowl, so when (in a couple of hours' time) you remove 150g to bake with, you'll still have some left in the bowl to continue looking after.
22. The starter which is to be returned to the fridge, can be partially discarded - leaving you with 1/6 of a cup (40g) and this can then have a DRIER feed of 1/6 cup (20g) of flour plus just 1 tbsp (15g) of COLD water and be covered securely with the plastic lid and put in the back of the fridge if you won't be baking for the next three days plus. If you are planning on baking within the next three days, just keep the starter at room temperature in your kitchen (covered with a cotton cloth, secured with an elastic band) and feed it twice daily using the usual discard and feed amounts.
23. Happy sourdough experimenting!