This is not the first time I have made a video about milk. In the previous episode I compared four breads: one made with only water, one made with milk, one made with milk powder, and one made with plant milk. The results were interesting, and you should definitely watch that video if you want to learn more about milk in breadmaking.
This time I decided to compare milk against other milk products. This is a video requested by you. Some people were asking me about yogurt and others about buttermilk. Both ingredients commonly used in breadmaking. I decided to add another one which was sour cream.
While milk, buttermilk, and yogurt are quite normal ingredients in bread dough sour cream is a bit more unusual and I had never heard of a recipe using it (or at least using it to replace all the liquid in that recipe). The main reason why I chose it is because I am Eastern European, and our blood is pretty much made of sour cream. We eat it with everything.
Before we start baking, we must know the stats and facts.
Knowing the composition of each ingredient takes the guesswork out of creating a recipe. There are a few important components to consider when substituting water for other liquids. The most important one being the water content of that ingredient.
Milk is made up of around 90% water. Buttermilk has around the same water percentage as milk. Yogurt is around 85% – 88% water depending on the amount of fat it contains. And sour cream has the least amount of water with only 74% or less. The main reason being that it contains a larger proportion of fat.
Naturally, fat is another important variable when using milk products. Milk can be as low as 0.5% and more than 2% on the other end of the spectrum. Buttermilk is quite lean with only 0.5% fat. Yogurt can vary a lot, but the one I used this time had 4% fat. Sour cream is the fattiest and usually ranges between 15% and sometimes close to 25%. I used sour cream with a fat content of 18%.
Fat makes the dough looser and the resulting bread softer and lighter.
Finally, the sugar content. Sugar will make the bread sweet, soft, and help with the browning of the crust as the bread bakes. The milk and buttermilk used in the video both contained 5% sugar. The yogurt and sour cream both contained around 4%.
Things to consider.
Before you start calculating, there is a choice to make. Using different liquids can result in the final dough having a different acidity/alkalinity. Up to a certain point (around 3.0pH) more acidity can greatly influence the hydration capacity of gluten. The more acidic the dough the more water you can add to it.
On the other hand, the more neutral/alkaline the looser and softer the dough will be and the less water it will be able to handle. Milk has a pH of around 7. The other milk products are more acidic at around pH 4.5.
So, you can either increase the hydration of the dough to compensate or stick with the same hydration and have a stiffer dough. The advantage of having a stiffer and stronger dough is that it can take more fermentation. It can produce a taller loaf and it can be fermented for longer. The advantage of a higher hydration is that it will result in a more open crumb and better keeping quality.
I chose to aim for the same hydration in all breads to really see the difference.
How to substitute water for any particular milk product.
We know that milk & buttermilk are both 90% water. Yogurt is 88% and sour cream is 74%.
The base recipe contained 140g flour, 95g water, 1.5g yeast, 2.5g salt.
The hydration of that recipe was 68%. 140 x 0.68 = 95g water.
To calculate the amount of milk or milk product needed, we must divide the water content in the base recipe by the water content percentage of each ingredient.
Milk (95g : 90% = 105g)
Buttermilk (95g : 90% = 105g)
Yogurt (95g : 88% = 108g)
Sour cream (95g : 74% = 128g)
If you were to make a recipe using fat and sugar, then consider the amount of fat and sugar in each ingredient and adjust the rest of the recipe accordingly.
As mentioned above the lower pH tightens gluten and that was clearly evident in the video. The milk dough was much looser and wetter than the other three.
During final proofing the doughs made with milk and with sour cream were expanding more quickly than the other two. The milk dough was loose because of the higher pH and that is why it was expanding so well. The sour cream dough contained the most fat which weakened the gluten and allowed it to expand more quickly than the buttermilk and yogurt doughs.
After baking we could observe the crust colour. The milk and buttermilk breads had the darkest crust because of the slight increase in sugar content which contributed to the browning. The yogurt bread had the dullest looking crust. The sour cream bread was not very brown either, but it did have a beautiful shine to it.
Cutting the loves open and smelling them revealed a clear progression of sweet to increasingly acidic aromas. Milk being the sweetest and sour cream being the most acidic.
Texture wise the milk and sour cream breads had the softest interiors. With the buttermilk and yogurt ones being slightly tighter.
Taste wise the milk bread was slightly sweeter than a regular loaf made with water would be. Buttermilk and yogurt loaves had a slightly more intense flavour with hints of acidity but also sweetness.
The sour cream bread had the richest taste and mouthfeel. It was sweeter and softer, slightly acidic, but also rounded and mellow. A clear winner in my book.
Taste and texture are highly subjective so you should try it out for yourself and see what you like best.
Watch the video here