Hi everyone, Julie from Savvy Eats here!  For those of you who are unfamiliar with my blog, I am a Food Science & Engineering student at the University of Wisconsin-Madison, graduating in May. I’m an unusual engineering student in that I don’t want to do super-technical work when I graduate. What I really want to do is write about food. More specifically, I’d like to write about the science behind food.  To that end, I am starting a new series this week on my blog answering all your food science questions!

For my guest post today, then, I thought I’d explain why yogurt is a good source of calcium, but cottage cheese is not.  Hey, I live in Wisconsin, aka Dairyland, so it is entirely appropriate for my first post!

First of all, whole milk is essentially a bunch of fat molecules trapped in a water-based fluid.  The only reason that the fat and water don’t separate is that the proteins in milk keep it from doing so.

There are two types of proteins in milk.  Most of the proteins are casein, which are not soluble in water, but about 20% are whey proteins, which can dissolve in water.

That is the important part to keep in mind.

Whey = Soluble in water.  The green-ish liquid in the picture below, from food-info.net.

Casein = Not a fan of water.  Not water-soluble and therefore steers clear of it as much as possible.  Oh, and all the calcium is naturally found in the casein, not the whey!

Cottage Cheese

To make cottage cheese, the casein must be separated from the whey.   When this happens, the calcium leeches out of the casein and into the whey proteins.  Since all of the casein and only a little of the whey is curdled to make cottage cheese, then, there is very little calcium.

To summarize

Whey = Now has the calcium, and isn’t in cottage cheese.
Casein = Becomes cottage cheese, but has lost its calcium to whey.

Yogurt

To make yogurt, both the casein and whey proteins are curdled together, so none of the calcium leeches out.  Yogurt, then, is a great calcium source!

Yogurt = Contains casein + whey, and therefore keeps the calcium!

I hope you have found this interesting and enjoyable.  I’ll be posting soon on savvyeat.com about why you can use a flax/water mixture in the place of eggs when baking.   I hope you’ll check it out!

Well the end of the week is here and what a week it was.  Lets end the week with an educational post to take you through the weekend.  I get a lot of questions about what knife to use when you are chopping versus what knife to use to slice bread etc.

This post will give you the basics of what knife to use depending on the task in the kitchen.  Just be aware that not all knives are created equal.  The length, width and edge of the blade as well as the shape of the tip are suited for specific culinary tasks.

Before you slice; think twice.

Slicing Knife
	Ranges roughly from 8-18 inches in length, with a thin, narrow blade to ensure smooth slices with a single stroke.  This is excellent for carving meats on Sunday dinner or when cutting those huge vegetables or even cakes and pastries.
Bread Knife
	Pretty self explanatory, the serrated or scalloped edge is designed to cut cleanly through tough materials such as bread crusts and some vegetables.  It is ideally used on food that has a  hard outside and a soft tender inside such as a loaf of homemade bread.
Chef’s Knife
	Maybe the most used knife in the kitchen – the chef’s knife is ideal for a large range food preparation.  It is usually around 8 inches in length, the cutting edge is shaped to allow a rocking motion on a cutting board  – making it the chopper of choice.  I also like to use the blade to crush garlic and other herbs.  The tip is good for paring and peeling fruits as well.
Santoku Knife
	I place this knife somewhere between a chef’s knife above and a butchers knife.  It is great for cutting. mincing and slicing.  The indentations on the blade are designed to prevent food from sticking to it as you slice.  I love that feature.
Utility Knife
	As the name states… is really a must have in the kitchen for all jobs.  It is great for peeling, slicing and cutting.  It is traditionally about 5-7 inches in length.
Paring Knife
	Highly versatile and a must have as well.  The paring knife is great  for cleaning, paring, peeling and slicing of small fruits and vegetables.

In Summary

So there you have it.  That is my take on the 6 common knives in the kitchen.  As for me- I feel if you only have three types of knives… they should be the:

1. Chef’s Knife
2. Bread Knife
3. Paring Knife

I hope you have a great weekend! I have a few fun and delicious things in store for you for next week – Stay tuned!

Take care

zesty