What is it?
There are several traditional methods for creating starters for breads. All of these starters are easy to prepare.
A starter usually consists of a simple mixture of wheat flour, water, and a leavening agent (typically yeast or a sourdough culture). After mixing it is allowed to ferment for a period of time, and then is added to bread dough as a substitute for, or in addition to more yeast. So pre-ferments are critical for best tasting bread – You can call it a starter, biga, poolish, preferment, or sponge – they all do sort of the same job and only really differ by water content.
Biga and poolish are terms for pre-ferments used in Italian and French baking, respectively, for sponges made with domestic baker’s yeast. Poolish is a fairly wet sponge (typically made with a one-part-flour-to-one-part-water ratio by weight), while biga is usually drier. Bigas can be held longer at their peak than wetter sponges, while a poolish is one known technique to increase a dough’s extensibility.
Why use it?
The primary difference between making bread with a starter and making bread with the direct or straight yeast method is that starter breads require much more time to prepare, but the flavor and texture of the bread is almost impossible to achieve with other leavening methods. Bread made with starters like poolish and biga also tends to keep better, compared to bread made from straight doughs.
Poolish & Biga tips
- If you are working with pre-fermented doughs like poolish or biga make sure not to ‘over ripe’ your pre-ferment. This is especially true when using larger percentages of preferment in your final dough (think up to 50%) because over riping will kill the gluten in your preferment (the yeast will eat them all) and you will end up with a weaker and hard to handle dough.
- The higher the percentage of pre-ferment you use the more your bread crumb will have a nice chewy texture (but it stops at around 50%). We like our bread that way, it gives you something to chew on. The sugars that are released from the flour in the pre-ferment also add a nice golden colour to your bread.
- Yes you can make make the same bread recipe using a biga or a poolish, you just need to make sure you adjust the water content.
- You can make a poolish or biga from another type of flour than the one you are using for the actual bread. For example, we use spelt, rye or whole wheat flour to add extra (and different) flavours to our bread.
Percentage of instant dry yeast in poolish
You can prepare your poolish up to 8 hours but also up to 16 hours in advance. But you have to adjust the amount of instant dry yeast you use. Logically, the more time a pre-ferment gets, the less yeast you have to use.
This is the schedule we use
Poolish up to 8 hours in advance – 0,23% – 0,33%
Poolish up to 12 hours in advance – 0,1% – 0,2%
Poolish up to 16 hours in advance – 0,03% – 0,08%
Example – How to calculate the right amount of yeast
You make a poolish consisting of 200 g flour and 200 g water. You make it 12 hours in advance (typically the night before the morning of baking) and it is summer or a nice warm room temperature for the poolish to ferment in.
You calculate the amount of instant yeast needed as follows: 200 g (amount of flour) x 0,1% (yeast amount used in summer for 12 hour poolish) = 200 / 100 x 0,1 = 0,2 g yeast (for fresh yeast multiply the amount by 3)
What does 0.1 gram of yeast look like?
To give you an idea of how tiny the amount of 0.1 gram of instant dry yeast is we have made some pictures. The third picture shows 0.1 grams of yeast in a teaspoon, the last picture shows 0.1 grams of yeast in a 1/4 teaspoon.
To give you an idea of how much instant dry yeast goes into a measuring teaspoon:
1 tsp dry yeast = 3,1 g
1/2 tsp dry yeast = 1,6 g
1/4 tsp dry yeast = 0,78 g
is something worth considering.
Also check out our recipe for pizza dough with a poolish
Find our favorite bread recipe with a sourdough culture based poolish here
By ‘over-ripening’ the pre-ferment, do you mean leaving it too long (how long is too long?). And are you saying that the yeast will eat the gluten?
Thanks!
When you have just mixed the poolish and you stir it with a spoon it will fight back because of the newly formed gluten. Within a few hours bubbles start to appear and the poolish starts to rise a little bit. After this fase (6-10 hours) the poolish will become ‘stringy’, when you pour it from your bowl you will notice long strands within the dough. These are the gluten chains which have been formed by magic and the poolish will grow in size and become airy. However the yeast and bacteria (if you use a sourdough starter) need ‘food’ to produce acid and bubbles and they kinda chew on these chains of gluten/starch to make little bite size pieces of carbohydrates to feast on. This is a good thing because this gives the poolish its complex sweet taste; big sized carbohydrates/starch of the wheat broken down into multiple type smaller carbohydrates. During the next stage the yeast makes alcohol and the poolish starts to foam and possibly collapse because of over-fermenting; the gluten weaken and can not hold the air any more. You should use the poolish before it starts to foam and collapse, this is where the poolish passes on its best qualities to your bread. If you wait even longer the poolish will because soupy, all gluten have been broken down by the yeast, you can stir it with a spoon without noticing any structure.
Hope this helps!
Ed
Gluten is a protein and fermentation only affects starches. So how can gluten be fermented? Could it be that the gluten is affected in a different way maybe by the by-products of fermentation like acidity etc…? I am trying to understant…
Hi Dee,
I do not know if the model of the process we describe about the bacteria or yeast chewing on the gluten is 100% scientifically correct, however the end result is the same. When a preferment over-ripens the dough/gluten structure turns into soup.
Gluten is a protein. My understanding is that the gluten is not broken down by fermentation(yeast) but by enzyme reactions. You can think of the gluten as a the skin of a balloon and over time, that balloon will have holes eaten in it by the naturally occurring enzymes. Enzymes break down proteins, that is why papaya, high in natural enzymes, is often used to marinate meats and as a natural digestive.
Thank you for your very helpful addition Reynaldo!
I read in “Cook’s Illustrated”, that the poolish is most active when it is just on the brink of collapsing, when the bowl is gently tapped. What is your experience?
Yes, that is our experience too. The challenge is to find that ‘brink’ point of course, before the collaps. One of the tell tale signs is the poolish starting to get a bit foamy before collapsing.
Thank you for sharing this useful tips. Perhaps you can add to the topic or explain how we should monitor the progress of the poolish.
I tried the one with 12 hours. I am not sure really which scale can really give me 0.1 gram so I just making a guess on how much is 0.1 gram. I tried with two pinch of yeast.
I made this at 11pm, when I woke up 6AM, I saw it triple in height. I marked it with marker.. I leave it until 11PM, however when I saw it. I actually dropped to double in height and the smell of alcohol is much stronger compare to 6AM one. In this case is the poolish still usable?
Thank you very much for putting such a wonderful website and share it with the rest of the world. Newbie like me appreciates it a lot.
Hi Irvan,
That is a good idea! And we will make a picture to show how much 0.1 g yeast is.
To answer your question: When it is overactive, all foamy and even collapsed the gluten structure will be weaker and you try to compensate by using less water in the final dough. This is only to rescue the poolish and you still really want to bake bread (don’t make a habit out of it, it will probably not be your best loaf ever anyway), it is better of course to use the poolish when it is nice and ripe and not collapsed. On the other hand, if the poolish is not yet fully active you can compensate by using a little bit more yeast in the final dough.
Thanks again for your suggestion and happy baking!
Ed
What does it mean to feed your starter? I understand you make a preferment and then use a portion of that to make your final dough for baking. Can you save that remaining portion of preferment and “feed” it to develop flavor and use again? If so, what could you feed it? Would it be carbohydrates and if so could you give me some examples to understand better? Thank you.
Hi Lori,
We know it can be confusing sometimes. This is how we understand and use it. A starter is a sourdough culture you maintain and use (and need to feed regularly to keep it strong and healthy!) to make a preferment. A preferment (poolish, biga, levain etc) you use in your final dough to add strength, taste, elasticity etc. to your bread. A preferment can be made either with yeast or a little bit of your sourdough starter. The preferment together with the other ingredients will make up your final dough.
Happy baking,
Ed & Marieke
I understand how using too little yeast will affect the development of poolish, dough, etc, but what happens if I use too much yeast? If, for example, I should have used 0.1 g of yeast in a poolish but I used 0.2 g by mistake, would the poolish reach (and pass) its prime twice as fast? That would make sense, but it’s harder for me to imagine the effect of too much yeast in the final dough.
If I should have used 2 g in the dough and I used 4 g instead, what would happen? If I timed everything as if I had used 2 g of yeast, what would be the effect of twice as much yeast on the finished bread? Would I just have wasted the extra yeast, or would the bread be adversely affected in some way? You can probably tell I’m new at this.
Hi Jim,
Your questions are not that easily answered. General amounts of yeast used in bread baking are around 1 – 2 % of the flour, by weight. Too much yeast can cause the dough to go flat by releasing gas before the flour is ready to expand. So it is not just a question of doubled the yeast so it will be ready in half the time (there are no general tables or schedules for that as far as I know), but of course times will be shortened when using more yeast (see above schedule). But there are also factors like water temp, final dough temp, room temp, humidity, etc. to consider and they are almost never the same. But most important, using (way) too much yeast can cause your bread to taste bitter due to way to much amino acids present. Plus the quicker the development, the fewer by-products the yeast produces and the less taste the bread has. And it will also have a different consistency. So yes, these are indeed adverse effects. So it would be best never to use too much yeast and if you do by accident, it is best to start over or maybe try to compensate by adding more flour and water (although this will alter your recipe altogether and the result will probably not be that good).
Hi!
I’m happy to see all these great questions and answers on your website! I’m having an issue with a Biga recipe that calls for 2 1/4 c. flour (o, ap or bread) 2/3 c water, tepid and 1 tsp. yeast. I cut these in half for a recipe I’m going to use in the future but I’m pulling my hair out as to why it’s not looking like a biga should. Per the authors recipe and the pic provided, it looks dry; nothing like a wet starter. Apparently there are many versions of this but I’m very sceptical of this recipe. I firmly believe that if I used 100% it would still look like my halved recipe. If there is any advice you could share, I’d greatly appreciate it. Thank You!
Hello Rose,
I think your recipe and book could be very well correct because a biga (as opposed to a more liquid poolish) should look dry, much more like a piece of dough (also see the second big picture above of what a biga looks like). Are you sure you did not confuse the two maybe?
Greetings,
Marieke
Hi,
Is it acceptable to let a poolish ferment in the fridge to lengthen the fermentation time. I asked mainly because it adds flexibility in making the poolish and using it, but I understand it can also help with flavour. If so, is there a general rule for converting time in the fridge for time at room temp, eg……….for a 4c fridge and 20c room temp?I’m guessing it wouldn’t be 5 times the time, ie a linear relationship! (The same goes for other spounges and doughs)
any advice would be greatly appreciated.
Great website
Regards
Tony
Hi Tony,
It is not straightforward or linear and we do not know or have read about any formula. You can see a chart here: http://www.weekendbakery.com/posts/a-few-tips-on-dough-temperature/ from which you can deduct that growth will more or less stop below 6 degrees C (that is what fridges are invented for, stop/slowing down of bacterial growth). My theory is that the yeast will be active during the cooling down period and more or less stops below 6C. So, a big piece of dough will take longer to get down to that temperature than a smaller quantity, something to also take into account. Also the activity is not linear to temperature as you can see in the graph in the post about dough temperature. What we usually do with the recipes is give it a trial run / educated guess based on experience and if necessary adjust the next time.
Hope this helps a bit.
Ed
Hi Ed,
That’s really usefull thanks. I made the poolish yesterday morning and put it in the fridge after an hour and took it out before bed. It looks fine this morning and I shall be using it shortly so we shall see!
So I guess as with most things baking it’s trial and error and learning to know when a poolish/dough looks ready! The chart is a really usefull guide and help to understanding the process so thanks for that. I’m a home baker so it helps to be able to be flexible with timings to fit it around daily life!
Thanks
Tony
ps I said I didn’t think the process would be linear.
Hi Tony,
Yes, I see that now, sorry for that hick up! And we totally understand where you’re coming from wanting to have the flexibility!
Glad you find the info and chart useful.
Have a wonderful Xmas time and an inspirational and successful New Year!
Ed & Marieke
Hi Weekend Bakers and Tony who posted a comment on 20 December 2012
I thought it might be useful to give you my own schedule for using a poolish to make wholemeal, seeded bread.
I make up a 50% poolish 24hrs before I want to start making the bread. I usually use 200g strong white (Carrs or Doves Farm), 200g stoneground rye from Bacheldre Mills, 1/4tsp dried instant yeast (as this is the smallest amount I seem to be able to measure accurately) and 400g water straight from the tap. I leave this at room temperature for a couple of hours then put it in the fridge for anything up to 24hrs but at least 12hrs. The following day I take it out and leave it at room temperature a couple of hours before I want to start making the bread. Then use it with 400g stoneground wholemeal, from Bacheldre Mills, 1 tsp instant dried yeast, 200g mixed seeds, 2 tablespoons black treacle, maybe 30g very soft butter, and between 160-180g tepid water. This gives a 70% hydration dough. I use the folding for 1 minute every 20 minutes for 3 folds method, then allow it to double in size. I then do minimal shaping into loaves and prove gain until about double. This produces a really light and tasty wholemeal loaf. The use of the fridge for the poolish gives the flexibility I need but you need to remember to bring the poolish to room temp before you use it or it takes forever for the final dough to rise. The actual amount of handling is very little but the time does the work. Delicious!
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