Scientific approach to ice cream

Out of curiosity, I did some research on what an ice cream, a physical standpoint. And I came across this audio interview of Derek Spore, which was in 2006 Scientist of the ice "at Ben & Jerry's.

The interview is very informative and greatly performed by Steve at Scientific American (one of the oldest magazines in the world!) Derek is joined by Eric, flavor guru, brings his culinary knowledge and in this discussion to the Geeks " food science. " You can of course listen to the interview online, or read the (very long) transcript in English. But here's a quick summary of the subjective

What is an ice cream?

An ice cream Ben & Jerry's is an emulsion of three phases: liquid, gas and solid. And yes, because even though they are frozen at very low temperatures, there is still some liquid elements. What is the gas present in our pots of ice cream? Well, the air! (As little as possible, you'll see it a little lower).

Constant cold

From a scientific perspective, you can eat your ice at any temperature, it concerns you;) However the temperatures at which ice is produced and maintained are very important, and any variation can significantly change the consistency of the product.

The ice creams are made of very small ice crystals. The goal for us is to get the biggest possible, and they are much smaller in our ice cream. If they grow, they become apparent and you feel when tasting:

The ice crystals grow when the ice is undergoing thermal shock, for example when the ice is out of the freezer to be served, and then given a few minutes after, or during cycles of defrosting the freezer. It was during the re-freezing, the ice crystals grow in groups, or other binder components.

When your ice cream is full of crystals, on the one hand it is less pleasant to taste, and secondly there is a risk that elements not very healthy to have joined the crystals. So do not eat it as well, even if it remains tempting;)

Derek advised to keep your ice deep inside the freezer, because nothing but a single opening door makes it already undergo a heat shock. Knowing that about 38-42% of ice cream is solid, and the rest is made of water, these crystals can be formed fairly easily if the pot of ice is not well preserved.

In the interview, Derek explains that each recipe is a new physical challenge. While some compositions are excellent when done, some may be very sensitive to thermal shock and is therefore less well preserved.

We also have a room that can test in two weeks that will live on an ice cream a year. And yes, because even in strict cold chain, your ice cream will only continue to suffer from thermal shock:) So we make sure that the mixture is stable and stores well over a year or more.

Less air there, the more good

In the interview, Derek also explained that equivalent volume, ice cream Ben & Jerry's weigh heavier than the first pot of ice came. And this for two reasons:

* Our recipes are delicious, full of chunks, fudge ...
* There is less air in each jar (less than 20% against 50% overall for an ice cream "standard")

This might also explain why our ice cream takes longer to soften the ice less greedy.
That tells you a little test product?

Derek also reveals the number of pots of ice every employee Ben & Jerry's can bring free at home at night. Sorry, but prefer not to disgust you, I will not give you this number)

In another article, Derek said he led a very serious tests where lovers gave their opinions on new fragrances, and were even paid for! If the concept is fun for tasters, Derek has a very rigorous approach to these tests: for example it is known that after having rejected a new perfume, a person will overstate the ice that will follow. The scores were then weighted according to the context.

Derek thank you for telling us about his dream job (after the flavor guru)! I know who will be tempted by a specialization in "food science";)