Baking - Breads, Ingredient Insights

Water Temperature for Yeast

My post this week comes from a friend who asked:

How warm does the water have to be for the yeast to proof right? (Is, in fact, the temperature of the water related to the proofing of the yeast?) I was always taught to do lukewarm water (it’s possible my water is generally more than lukewarm—does that kill the yeast?) and then add some kind of sugar/honey for the yeast to eat, and then it will all work out right. But it never seems to bubble up quite like I want it to. How to change this?

This question made me automatically think back to the classes I took, and a formula we had to use whenever we made yeast breads. To get very technical for a moment, the recipes we used in our ‘professional’ book listed a temperature for the dough, usually anywhere from 78°F to 86°F. This is the temperature at which the dough should be for the best fermentation/proofing results (yeast has its best growth from 70°F-90°F). To figure out the right temperature for the water we had to multiply the desired dough temperature by three, then subtract the room temperature, the flour temperature and the machine friction temperature.

IMG_4168For example, a recipe for brioche in my book says that the dough temperature should be 84°F. Multiply that by three to get 252. The room temperature was 64°F, the flour was 58°F, and we always used an average temperature of 20°F for the machine friction. Take 252 and subtract 64, 58 and 20, and we get 110, so the temperature of the water should be 110°F. I can remember holding my thermometer under the water until it reached the right temperature, filling the measuring cup, and taking the temperature of the water again in the cup just to be sure. We also used fresh yeast for our recipes, so it didn’t need the initial proofing. However, the book instructs that if you are using active dry yeast, it should be “rehydrated in four times its weight of warm water (about 110°F).”* If the water is too warm it can definitely slow down the yeast’s growth, and warmer still will kill the yeast (140°F).

If you don’t have a digital thermometer, don’t worry. It would give you a more exact temperature, but it’s certainly not mandatory in order to get good bread. You can measure the temperature of the water like you would for a baby’s bottle. If the water feels hot on the inside of your arm, it’s probably too hot for the yeast; if it feels lukewarm on the inside of your arm, it’s probably okay; and if it feels cool on your arm, it’s probably too cold.

There are several other factors that can affect how your dough proofs.

  • Adding sugar or honey will definitely help speed up yeast’s growth. Yeast consumes the sugar and turns it into carbon dioxide and alcohol – the gas contributes to the leavening, and the alcohol is evaporated while baking. Extra sugar is not absolutely necessary, in fact many of the recipes I have don’t even call for sugar when you’re initially softening the yeast. As you make the dough the yeast feeds on sugars in the flour, but added sugar (as long as it’s in the recipe) can speed things along. If you have too much, it may make it go too fast, which can cause it to over-ferment and not come out very well.
  • Dough proofs best from 78°F to 86°F, so if you have the dough in a cool room it may not rise as well; conversely, if it is too warm it can slow growth, or kill the yeast (so don’t proof it on the vent of the oven as it preheats like I used to). I’ve heard several people say they use the top of their fridge, as it is generally warm to being with, and it is higher up in the room (warm air rises).
  • The length of time needed can vary. It is important to follow the recipe’s guidelines, but if your proofing temperature is higher than normal it will likely take less time than what the recipe calls for. It’s best to just pay close attention to the dough and watch for when it has actually doubled in bulk.

The most important thing is to keep trying. If it didn’t work well, adjust something for the next time and see if it makes a difference: add a little more (or less) sugar; try letting the dough rest in different places; try different temperatures of water; try different types of yeast if you have them available (active dry, instant, or fresh). Just make sure you keep track of what you did so you remember what works well. Happy Baking!

*Gisslen, Wayne (2005). Professional Baking (4th edition). Hoboken, New Jersey: John Wiley & Sons, Inc. p. 51.

Baking - Breads, Ingredient Insights

Waffles: Yeast vs. Baking Powder

With my waffle maker came a small collection of waffle recipes, and I was surprised to see that they all used yeast for leavening. Growing up we just used a box of pancake mix, which contains baking powder (somehow they always tasted different from pancakes, even from the same box!), so I thought that waffles were always a quick-bread.

I also noticed in the small recipe booklet that most of the recipes called for separated eggs, where you had to beat the whites to stiff peaks and fold them in to the rest of the batter at the end. This sounded like a lot of work, so the first few times I used my waffle iron, I followed a recipe that you let sit overnight. The yeast would work its magic overnight (kind of like the no-knead bread), and then it was ready to cook when I got up in the morning. That recipe makes nice, crispy on the outside, chewy on the inside waffles, that I must say were more like what I’d get in a restaurant than the pancake mix ones we made at home.

I made some waffles on the weekend, but followed a recipe from my favourite bread cookbook, which used baking powder, and also called for separated eggs. I was curious to see what the difference would be. These waffles came out much more dense, and reminded me more of a soft muffin. They were still good, but a very different texture from the lighter yeast ones with which I’m now familiar.

I was also more inclined to try a recipe with separated eggs because I could just toss the egg whites into my mixer and let them whip up while I got all the other ingredients together. It was a breeze! So now I will also have to try one of the yeast recipes that uses separated eggs and see how that goes. What a sacrifice, to have to eat more waffles!

Baking - Breads, Ingredient Insights

Warm Rising? Cold Rising? Understanding Yeast

yeast (2)When I was first learning about bread, one of the key points was that the dough needed to rise in a warm place. I never questioned this. And when I took my baking classes, this point was reinforced with a little more precision; the dough should rise in a place where the temperature is between 20C and 32C (or slightly above room temperature).

But my post from two weeks ago defied this ‘rule;’ the dough rose in the fridge, which is nowhere close to room temperature. And yet, I ended up with a couple loaves of lovely bread. How could this be?

I did some digging and discovered that letting dough rise at slightly above room temperature is the optimal temperature for dough growth, but not the only temperature for growth. Yeast becomes active when it is warmed, and with most of the yeast we use at home, moistened (commercial bakeries usually use fresh yeast, which is more like a putty texture than a dry granulated one), hence most recipes call for mixing active dry yeast with warm water for about five minutes. This wakes up the yeast, getting it ready to do its job.

Once the yeast is activated, it can be productive anywhere from 4C (normal fridge temperature) to 40C. The difference is in how long it takes for the dough to double in bulk. The lower the temperature, the longer the yeast will take to work. Hence, the bread recipe from two weeks ago needed to rise for at least two hours in the fridge, as opposed to the 45-60 minute rise time of a recipe done at room temperature. And once you get higher than room temperature (40C) the process also slows, because it is considerably warmer than what yeast likes.

So what are the benefits to cool-rise bread? It can be more convenient, if you don’t have the time to devote to the whole bread-making process at once; you can put it in the fridge and come back to it the next day to bake. It also creates more interesting flavours and textures the longer it sits – which explains the artisan-type bread from last week’s post. But don’t leave it too long! Like many things, if it is left too long to its own devices not-so-friendly bacteria can take over and leave you with an unappetizing mess! Be sure to follow a recipe until you get a feel for the timing.

You can read more about yeast and the fermentation process at Baking911 by clicking here.