What does 2-row, or 6-row mean?

[frijole]

I keep seeing this when i am looking at different extracts.

 

[Boerderij_Kabouter]

They are two different barleys. 2-row is the base standard, but 6-row has more conversion power. You don't need to worry about it until you start brewing all grain.

 

[kevmoron]

They are, broadly, two different families of barley. A 6-row barley has 6 rows of kernels on each ear. If you were to slice a cross-section of the ear, you would see 6 kernels. 2-row on the other hand, has only two rows of kernels, on opposite side of the ear, with the other four (two on each side) being undeveloped. 6-row tends to have more diastatic power than 2-row.

 

[944play]

 

[VTBrewer]

And for when you get to AG, while 6 row will convert rice, oats, corn more easily than 2 row, it also can result in more haze and requires a protein rest.

 

[david_42]

There's also 4-row, but it isn't used for brewing.

Working with extracts, 2-row/6-row matters very little because the sugars have all been converted and the enzymes denatured.