About reusing spent grain

IMO, the best use of spent grain is for food.

I made an amazing bran cake from the spent grain from a red ale. Not only are the grains. Spent grain has residual sugars that add a sweetness that improves a lot of foods. You can use them in pancakes, cakes, muffins, and you can even make granola with it.

Once you are done mashing/steeping, place your spent grain on a baking sheet lined with baking paper and place in the oven at a low heat with the fan for a few hours, turning the grains every so often to get the to dry out evenly. Once dry, put them in a blender or a coffee grinder, and then you are done! Enjoy your beer with snacks made from the grains.

I use second runnings / Parti-Gyle as often as I can. But as my primary mash efficiency rises theres less and less usefulness in the parti-gyle. As for me using the grains, it's compost or given away for chicken feed.

If your mash efficiency is still below 85% there's still plenty use in the parti-gyle.

I could usually get 5 gallons of 1.025-1.030 parti-gyle wort from a 12 gallon high gravity primary brew mash.

How to:

Slow Fly sparge for primary keeping mash water 1inch above grain. When primary beer is done sparging, stop the fly, stir and let the parti-gyle rest. When done with your primary boil, then batch sparge the parti-gyle wort.

Uses: Anything bellow 1.020 isn't very useful by its self. Most uses require adding a little DME, grain steep or sugar to bump it to the range you want.

Parti-gyle wort is low gravity and has many historical style uses like scottish-60.

It's great for starter wort. I boil and adjust to 1.040, Then refrigerate and strore in 1 gallon jugs.

It's great for malted ciders /light graffs, I find it even eliminates need to backsweeten. Especially if you steep in malts.

Tips

Don't mash out instead keep sparge around 154°, if you intend to allow the second mash to rest.

Adding a little more grain to second mash helps kick start a second conversion rest.

Add adjuncts to boost gravity.

Boil down to increase gravity. Usually pretty easy to get a fast violent boil since its usually 1/2 your normal volume.

Press the grains as the parti-gyle volaufs. I use a potato masher, works pretty well.

All in all how useful your parti-gyle is depends on a lot of factors and what its used for. I've only touched on the processes and uses as an overview.

Wow! That is economical brewing - but possibly too economical. There may be some colour and flavour left in the roast grains but there should be very little starch, malto-dextrins or sugars left in the malted grains. However there is a lot of grain husk left behind and that is a source of tannins and lignins that impart a bitter or more astringent taste to the wort.

So one might be able to make further use of some part of the steeped/mashed grain but one would necessarily have to add more malted grain and one runs the risk of making a strangely flavoured and astringent beer. As the only reusable part (roast grains) are relatively cheap there is little to be saved and lot of effort to be used to make a possibly inferior brew.

IMHO it would be better to attempt to make more efficient use of the roast grain in the first steeping/mashing process than to attempt to make use of any remainder in a second processing.