Does using different flour make a difference?

Flour is something we use everyday in cooking. There are so many types of flour available in supermarkets, too. When cooking, I always want to produce the best food I can, but you can only go as far as your ingredients will take you. So, in cooking, which flour is best for which food? Is it worth paying more for more expensive flours? How much do you “lose” for using the wrong type of flour? I don’t have a lot of experience with flours, so I decided to find out.

The main consideration in flour is gluten. Gluten is a complicated mix of wheat proteins that don’t dissolve in water. When wetted, though, the proteins can change their shape, forming and breaking bonds with each other. The gluten network changes its shape under pressure, reverts back to the original shape once the pressure is removed. This means when yeast produces carbon dioxide, the walls of the dough don’t break, important for bread-making. Similarly, this elasticity relaxes with time, keeping the dough taut. This network of dough and air gives the bread its texture: lightest, high-rising, chewy bread from high-gluten flour, as opposed to denser, crumbier bread from lower-gluten flour. So for some applications, you want lots of gluten, for others, you don’t:

Not all baked goods benefit from a strong, elastic gluten. It’s desirable in yeasted breads, bagels, and in puff pastry; but it gives an undesirable toughness to other forms of pastry, to raised cakes, griddle cakes, and cookies. For tender preparations, bakers intentionally limit the development of gluten (McGee on Food and Cooking, p523).

For bread, where we want the gluten network to develop, will be affected significantly by different types of flour:

“Bread flours” are milled from high-protein wheats, require a long kneading period to develop their strong gluten, and produce well-raised loaves with a distinctive, slightly eggy flavour and chewy texture. Lower-protein “all-purpose” flours give breads with a lower maximum volume, more neutral flavour, and less chewy texture, while flours from soft durum wheat with weak gluten proteins make denser loaves with a tender, cake-like crumb (McGee on Food and Cooking, p535).

Cakes on the other hand, don’t want the gluten network to develop, so we would expect softer flours to actually perform better:

A cake’s structure is created mainly by flour starch and by egg protein. The tender, melt-in-the-mouth texture comes from gas bubbles, which subdivide the batter into fragile sheets, and from the sugar and fat, which interfere with gluten formation and egg protein coagulation, and interrupt the network of gelated starch (McGee on Food and Cooking, p554).

So to test out which how different flours fared for different baking purposes, and how this theory turned out in practice, I got 5 varieties of flour, and then made some bread, and some cake. I usually make bread for everyday consumption, so price does factor in choice of flour considerably, but every now and then I would like to be able to make something a bit more exciting. Cakes I make much less often. Typically cakes are made to be eaten by others- birthday cakes, tea and cake, for example. So when I do make a cake, I want it to be good, so I’ll probably pay for better ingredients if I can. But just understanding how different types of flour worked, and what the end results were, was interesting in itself. The five varieties of flour tested were: Mcdougall’s Self Raising Supreme Sponge Flour (£1.78/kg), Tesco Everyday Value Self Raising Flour (£0.35/kg), Tesco Plain Flour (£0.60/kg), Tesco Strong White Bread Flour (£0.40/kg), and Allinson Strong White Bread Flour (£0.67/kg).

For reference, according to McGee on Food and Cooking, I would expect the bread flours to have protein contents of 12-13%, the all-purpose flours protein contents of 7-10%, and the cake flour 7-8% protein content. This is just part of the story though, there will be a lot of differences in milling methods and how the flours are processed, which contributes to the final product.

When making the case, I tried as much as possible to be scientific, although since I did not want to be overrun with cupcakes, I only made small quantities, and so relative measurement errors will have been higher. The recipe was as simple as I could think of: flour, butter, sugar, and eggs, so that any effects of different flours would be more easily seen. The cupcakes came out as follows:

Cupcake 1: Supreme Sponge Flour
Definitely the lightest and fluffiest in texture. Also, interestingly, this one came out the most bright, a very appealing yellow. The butter flavour had integrated really well into the flour, and there wasn’t a fatty taste leftover.

Cupcake 2: Everyday Value Flour
Crunchy, and with an uneven distribution of texture- the butter and egg seemed to have sunk to the bottom and not integrated properly with the flour. Poor development of flavours.

Cupcake 3: Plain Flour
Quite reasonable, the best of the rest. A little crispy, meally, and dry. I got more floury flavours coming through, so thought this one was the bread flour.

Cupcake 4: Bread Flour
Good crispiness on top, a little meally, but an uneventful cupcake. Very similar to the plain flour, hard to tell apart.

After we made the cupcakes, my resident cupcake enthusiast and I swapped the order around and tried to guess which was which. The only one we both got correct was the supreme sponge flour cupcake- significantly better than the others, it wasn’t really close. I thought the everyday value flour was easy too, having a significantly poorer quality texture. Neither of us could tell the plain flour and bread flour cupcakes apart, though. Conclusion: it’s probably worth paying the extra for supreme sponge flour, and don’t use cheap flour.

For the bread, I was more interested in the differences between different types of bread flour, but also how plain flour fared. It was particularly difficult to be scientific here, as I could not knead all the bread at once, so some batches had 15-20 minutes more rising time than others. As with the cupcakes, the bread recipe was as simple as can be, flour, water, salt, yeast. The rolls came out as follows:

Roll 1: Supreme Sponge Flour
A very white roll. Hardly rose at all. Bad aftertaste from the baking powder, but otherwise pleasant taste. Smooth texture, but very dense.

Roll 2: Everyday Value Flour
Less dense, and crusty. Tasted poor, with the bad aftertaste from the baking powder. A little meally. Didn’t rise a lot.

Roll 3: Plain Flour
Very crusty, dry, and dense. Neutral flavour. Didn’t rise a lot

Roll 4: Tesco Bread Flour
Good texture, nice leathery crust, risen considerably more. Nice bready taste.

Roll 5: Hovis Bread Flour
Very similar to the Tesco bread flour, no discernible differences.

Overall the results were pretty clear: you need a flour with high gluten content to make a good bread. The plain and everyday flours rose poorly, and, worse of the lot, the supreme sponge flour barely rose at all. Using different flour makes a big difference, so definitely buy some bread flour here. Within the bread flours, I didn’t notice any difference in the finished product, so the difference in price is what will drive my purchase here. Perhaps the Tesco bread flour is unexpectedly good. Conclusion: buy bread flour, it seems that the difference in gluten is more important than flour quality, as the theory suggests.

A fun afternoon’s baking, but I am pleased with the results. Of course, there are a lot of other things going on with flour than gluten, but it’s a start to understanding flours. It’s worth having confidence in the ingredients you use, and understanding properly what processes like kneading will do to the finished product. If you understand these, you’ll help get the cooking right, and food will taste better, which is really what it is about.

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Cookie Dough and Vacuum Cleaners

A lot of molecular gastronomy techniques are hard to implement at home, simply through lack of equipment. The perfect steak is meant to be cooked in a sous vide at 50-65°C, before finishing off with a blowtorch, for example. Xanthan gum and nitrous oxide are blasted through sponge cake mixture to give it the perfect texture. But when I saw a recipe for vacuum sealed cookie dough from The Kitchen as Laboratory, I thought the equipment needed could be improvised at home in a way that it couldn’t be for other techniques.

You might have seen in cookie recipes instruction to leave the dough in the fridge for a while, or even overnight. The idea is that the moisture in the cookie moves around the dough evenly, meaning that you get a moist, evenly baked cookie. The heat spreads around the cookie evenly, giving a nice even texture as well. Cookies which don’t have an even distribution of moisture can go crispy around the edges, and end up crumbly, rather than nicely chewy and soft.

To speed up this process of getting the moisture around the cookie dough, a technique called hydration is used. By subjecting the cookie dough to a low pressure environment, the moisture spreads through the cookie by capillary forces, to create an even distribution of moisture in the dough. This is done by putting the dough in a bag, the bag inside a vacuum chamber, creating a vacuum inside both the chamber and the bag, and then slowly letting the air back into the chamber, which gives the desired drop in pressure.

Cookie dough nested in a vacuum bag

Now, I don’t have a vacuum chamber, but what I did have was some vacuum bags (similar to these ones) which we use to store out-of-season clothes and duvets. By sealing the bags, putting a vacuum cleaner in the entrance, turning it on and then pulling the vacuum cleaner out right when all the air has come out, you can take all of the air out of the bag and keep it sealed up. Hopefully, given the principles were the same, I’d see the same kind of difference in results.

So, scientist as I am, I made a batch of dough and divided it in two, one to serve as the control. The control I would just bake with no resting time, and the other batch would be hydrated. I put the other batch into two sandwich bags, which were put into a vacuum bag and sealed with a vacuum cleaner. Then the air was gradually let back in, to create the all important low pressure environment. The cookies were then baked for the same amount of time, allowed to cool, and plated up.

Hydrated dough (bottom left) vs. Regular dough (top right)

Fortunately, the results were pretty clear. The control batch were crispy around the edges, and were much more crumbly and mealy than I would have liked. The hydrated ones were smooth, moist- consistently so around the edges. They also cooked a lot more evenly- spreading their shape out better. And just to make sure I’m wasn’t being biased with the results, the cookies were tasted by my local cookie enthusiast. She was pretty impressed with how the hydrated ones turned out, but perhaps more impressed that I had finally started to use the vacuum cleaner.

So why not hydrate the dough every time? Given that the extra step in hydrating the dough really wasn’t difficult, taking 5 minutes at most it is hardly extra effort, but had great results. However, I think the main success for me, though, is a molecular gastronomy technique that works well in the domestic kitchen. Cookie anyone?

Top and underside of the two cookies. The regular dough cookie is on the left, the hydrated one on the right.