There are several types of problems you can get with spent grains and spent hops.
-You can get vinegary and fermentation smells in the beginning
-Ammonia smells from being too rich in nitrogen later
-Anaerobic smells from going septic later
The vinegary and fermentation smells come from too much sugar or beer in the grains, which then attract hornets. The best way to combat this is to have higher efficiency and then to continue sparging with water to extract out all the sugar and starch; I use that water for irrigation so the water doesn't get wasted. Mixing in dry materials would probably help too.
To avoid ammonia smells, mix in browns (not grass clippings).
To avoid anaerobic, mix in enough dry materials so the pile isn't water logged and air can get into the pile.
In addition, it is much easier to reduce or avoid smells in the winter if you live in a cold climate. In the Chicago winter, I make no special provisions in managing the compost pile; I dump and run to where it is warm.
The last two classes of smell are automatically avoided if you mulch the spent grains rather than compost. For mulching, do a high efficiency mash and sparge, dump the grains, and hit the grains with water from a hose to spread the grains out, wash out the sugar into the soil and irrigate at the same time.