Mash Hopping

Hops can be added at several stages during the brewing process - in the mash tun, in the kettle pre-boil (first wort hopping), during the boil, at flameout, steeping post flameout (or recirculating through a hop back) and during secondary fermentation (dry hopping). Of course, you can also add more at dispense via a randall or hop rocket. The first of these, mash hopping, is something I'd only heard of recently and it got me thinking about the science behind it. 

The mash usually occurs at somewhere between 63 and 70 degrees celcius, depending on the style and the amount of fermentables the brewer wishes to extract. Sparging usually occurs at a slightly higher temperature, say around 74 to 78 degrees celcius. All of these are below the temperature isomerization occurs, that being around 80 degrees celcius. So mash hopping will add little to no bitterness but could potentially add flavour and aroma - in a way a replacement for steeping or dry hopping in that the effects are similar.

A twitter thread on this subject yielded mixed reviews as to the benefits of mash hopping. Some, like me, seemed cynical whereas others thought it was beneficial. I suppose the only real way of determining the benefits would be to run a side-by-side test, perhaps brewing the same beer twice with and without mash hopping. In an article published in BYO magazine, author Chris Colby did just that, with positive results.

Are any commercial breweries out there mash hopping? Have any home brewers tried it and to what effect? I'd welcome any feedback on the subject and might just give it a try next time I'm brewing a beer where maximum hop flavour and aroma is called for.