Butterfat
<p><b >Butterfat</b> or <b >milkfat</b> is the <a href="http://en.wikipedia.org/wiki/Fat" title="Fat" >fatty</a> portion of <a href="http://en.wikipedia.org/wiki/Milk" title="Milk" >milk</a>. Milk and <a href="http://en.wikipedia.org/wiki/Cream" title="Cream" >cream</a> are often sold according to <a href="http://en.wikipedia.org/wiki/Fat_content_of_milk" title="Fat content of milk" >the amount of butterfat they contain</a>.
</p>
<h2 >Other cream products</h2>
<div class="thumb tright" >
<div class="thumbinner" ><a href="http://en.wikipedia.org/wiki/File:Milkproducts_v2.svg" class="image" ><img src="/d3225311-805e-5241-a56e-f032f11a1b9a.png"/></a>
<div class="thumbcaption" >
<div class="magnify" ><a href="http://en.wikipedia.org/wiki/File:Milkproducts_v2.svg" class="internal" title="Enlarge" ><img src="/eed40751-d4fd-54b5-9d05-60bef813f3c4.png"/></a></div>
Chart of 50 types of milk products and relationships, including cream (click on image to enlarge).</div>
</div>
</div>
<p ><b><a href="http://en.wikipedia.org/wiki/Butter" title="Butter" >Butter</a></b> is made by <a href="http://en.wikipedia.org/wiki/Churning_(butter)" title="Churning (butter)" >churning</a> cream to separate the <a href="http://en.wikipedia.org/wiki/Butterfat" title="Butterfat" >butterfat</a> and <a href="http://en.wikipedia.org/wiki/Buttermilk" title="Buttermilk" >buttermilk</a>. This can be done by hand or by machine.</p>
<p>
<b><a href="http://en.wikipedia.org/wiki/Whipped_cream" title="Whipped cream" >Whipped cream</a></b> is made by <a href="http://en.wikipedia.org/wiki/Whisk" title="Whisk" >whisking</a> or <a href="http://en.wikipedia.org/wiki/Mixer_(cooking)" title="Mixer (cooking)" >mixing</a> <a href="http://en.wikipedia.org/wiki/Air" title="Air" class="mw-redirect" >air</a> into cream with more than 30% fat, to turn the liquid cream into a soft solid. <a href="http://en.wikipedia.org/wiki/Nitrous_oxide" title="Nitrous oxide" >Nitrous oxide</a> may also be used to make whipped cream.</p>
<p>
<b><a href="http://en.wikipedia.org/wiki/Sour_cream" title="Sour cream" >Sour cream</a></b>, common in many countries including the U.S. and Australia, is cream (12 to 16% or more milk fat) that has been subjected to a <a href="http://en.wikipedia.org/wiki/Bacteria" title="Bacteria" >bacterial</a> culture that produces <a href="http://en.wikipedia.org/wiki/Lactic_acid" title="Lactic acid" >lactic acid</a> (0.5%+), which <a href="http://en.wikipedia.org/wiki/Souring" title="Souring" >sours</a> and thickens it.</p>
<p>
<b><a href="http://en.wikipedia.org/wiki/Cr%C3%A8me_fra%C3%AEche" title="Crème fraîche" >Crème fraîche</a></b> (28% milk fat) is slightly soured with bacterial culture, but not as sour or as thick as sour cream. Mexican <b>crema</b> (or <b>cream espesa</b>) is similar to crème fraîche.</p>
<p>
<b><a href="http://en.wikipedia.org/wiki/Smetana_(cream)" title="Smetana (cream)" class="mw-redirect" >Smetana</a></b> is a heavy cream product (35-40% milk fat) Central and Eastern European sweet or sour cream.</p>
<p>
<b>Rjome</b> or <b>rømme</b> is <a href="http://en.wikipedia.org/wiki/Norway" title="Norway" >Norwegian</a> sour cream containing 35% milk fat, similar to <a href="http://en.wikipedia.org/wiki/Icelandic_language" title="Icelandic language" >Icelandic</a> <b>sýrður rjómi</b>.</p>
<p>
<b><a href="http://en.wikipedia.org/wiki/Clotted_cream" title="Clotted cream" >Clotted cream</a></b>, common in the United Kingdom, is cream that has been slowly heated to dry and thicken it, producing a very high-fat (55%) product. This is similar to Indian <b><a href="http://en.wikipedia.org/wiki/Malai" title="Malai" >malai</a></b>.</p>