Fat in malted and unmalted barley

Question

Does malted barley have fat like un-malted barley?

If either have fat, why doesn't this cause problems in the beer? What happens with this fat during the brew?

Answer 1

Since this question keeps getting bumped, I thought I'd have a go at it. Here are a few relevant points from the literature.

Malt has slightly less fat than unmalted barley:

"Up to 4% of the dry weight of barley is lipid and 3.4% in the case of malt." _{(corn and oats may both reach 6+%)}

"30% of the lipid content of barley grains disappear[s] during germination."

To give you an idea of what happens to this fat during the brew:

"[Lipids] tend to associate with insoluble components of the mash, and therefore they are largely lost with the spent grains and become associated with hot and cold breaks."

"Rapid wort-separation techniques are liable to give worts containing elevated levels of lipids"

"The method of separation of sweet wort from spent grains has the most significant effect on wort lipid content [...] just 0.3% [of malt lipids are released into the wort] in the case of a mash tun." _{(Up to 4.5% of malt lipids can make it into the wort in rapid-separation systems)}

"[Up to] 91% of wort lipids in the [boil] were deposited with the trub in the whirlpool"

From breweries surveyed, total lipid content of worts ranged from 10-140 ppm, depending on the wort separation method.

_{(quotes taken from Brewing Yeast and Fermentation, Scientific Principles of Malting and Brewing and Malts and Malting)}

So you can see how little of the fat content tends to make it into the wort from raw materials, and most of that is eliminated before fermentation.

Answer 2

Neither has a discernible amount of fat. Unlike oats. With oats the fat lends to the creaminess you taste in say oatmeal stouts.