spent grains in extract?

[lazarwolf]

Any one ever try this? I'm doing a biab, I have some extra extract, I have hops... not looking for the spent grains for gravity, just for some color, mouth feel, some complexity.

Thought I'd ask, if it works, that's X2 the beer on just a little more cost. Kind of a poor man's 2nd running or parti gyle.

 

[grrickar]

Wouldn't you run the risk of releasing tannins if you used spent grains? If I were to use them I think I would put them in a bag and treat it like a partial mash and make a grain 'tea'. At least then you could sample it and see if the taste was on point before you add it to the boil kettle.

 

[Yooper]

The reason partigyle brewing works is because the first batch is a very high OG, no sparge, brew.

There are still enough converted sugars in the mash to make another beer, if sparging is either not done or stopped while there are still plenty of sugars remaining.

If the grains are actually "spent"- that is mashed, sparged, and down to under 1.020, the only thing left to extract are flavors from the husks (tannins).

 

[lazarwolf]

Still a new guy to all grain. I really appreciate the help. But I don't plan on sparging. So there should be sugars and other mashy goodness that wash off. My idea is to put the grains into a cold kettle and pull them at 168 or so. If my pH is stable, shouldn't that work?

 

[grrickar]

I'd go with lower temps, like 150-155F, steep them for awhile, then draw off some wort and see how it tastes. If it is off, I'd suggest not using it. If it isn't sweet, then the sugars are already rinsed from the grains and they are spent. If it is bitter, you are extracting tannins, which isn't what you want...

 

[IslandLizard]

[...] If the grains are actually "spent"- that is mashed, sparged, and down to under 1.020, the only thing left to extract are flavors from the husks (tannins).

1.020 is too high to stop at. The most used end-gravity target when fly sparging is 1.008-1.010. Batch sparging is a bit different as the gravity changes in intervals with each sparge. And you still would not sparge below that same value.

I know you know this, but for the OP, and the record:
pH is important as the more you sparge the more the buffering capacity of the mash drops. Sparge acidification is definitely needed to prevent tannin extraction, which starts above pH 5.8.

To the OP:
You should taste some of the later runnings and hope to trace some of those flavors and colors you're after. It's pretty thin stuff once you go below 1.020.

So, sparge your mash to increase efficiency. If you batch sparge, do so 2x with half the volume each. Unless you're after a very high OG wort, where sparging is out of the question, you could use the 2nd and subsequent runnings for a small beer or add more grain and do a complete mash for your 2nd beer, again, followed by 2 batch sparges.

There are other ways to make 2 or more beers out of 1 mash. The Nov/Dec 2014 issue of Zymurgy Magazine had a great article how parti-gyling was historically done in England, and way, way beyond today's over-simplified concept. It was common for small breweries to produce 8-12 beers from the same basic mash.

Added:
I see you're doing BIAB, which is typically sparged sparsely, but squeezing is well accepted.

You can run the calculations yourself. After dripping "dry," measure the volume and gravity of the liquid after a good squeeze. That's how much you gained (points). Then weight the wet sack and subtract your grain bill. The difference is the weight (volume) of wort at that gravity which is left behind. Your call to see if it is worth reclaiming with a sparge and/or a more thorough squeeze.

 

[grrickar]

I'd also concern myself with the way the spent grains are/were stored. Is this spent grains from a brew a week ago, or are you just looking to brew a lower gravity batch back to back with a higher gravity from the first runnings (aka partigyle)?

 

[lazarwolf]

Great stuff, I'd be using the grains immediately of of a high og beer. PH could be a concern. But I'm suplement the 2nd with dme.

 

[grrickar]

Great stuff, I'd be using the grains immediately of of a high og beer. PH could be a concern. But I'm suplement the 2nd with dme.

Check the flavor and maybe take a hydro or refracto reading to see if you are getting anything useful from the spent grains. If there are extra sugars to be had, you'll need that info to know how much DME to add if you are shooting for a particular OG for the second beer.