Advice after first all grain brew...

[DavidSwede]

Hi! Just completed my first all grain brew... everything went relatively smoothly apart from one thing.

I prepared 19 litres for the mash intending to finish with 16 litres after boiling. In terms of proportion the same as what seems to be a common 6 gallon to 5 gallon ratio.

I poured 14 litres in the original mash intending to use the remaining 5 to wash the grains. After doing all this I was left with only around 15 litres and so after the boil only 13. (I was using a 24 litre cylindrical cool box with tap and 15cm bazooka)

Is it normal to lose this much water in the mash or is it a case of working harder to squeeze out every last drop?

Thanks in advance for any replies!!

David.

 

[urg8rb8]

The grains will soak up a big amount of water.

 

[bigjohn1895]

that's about how it goes I'm still dialing in how much water the grain soaks up
last batch I used brewers friend and it kinda helped seemed like its guess was closer then mine

 

[someguybrewinginco]

Yes, there's the grain loss plus depending on your equipment setup you may have loss at the bottom of your lauter tun. Additionally, you don't always want to collect every last bit of sparge water since as the sparge progresses the pH of the water rises which will extract more tannins and bitterness from the grain.

As an example, in a recent porter I brewed with a 15lb grain bill, I used a total of 10.6 gallons of water to hit my target pre-boil volume of 7.7 gallons. I have .7 gallons of deadspace at the bottom of my lauter tun, I left about a half gallon in there that I could have drained out which means the grain absorbed about 1.75 gallons.

Less grain less absorption, you get the idea but you do need to dial in your system.

 

[kombat]

Grain will absorb about 0.1 gallons of water per pound. Also, your mash tun and boil kettle have "dead space" that needs to be accounted for. And finally, there's your boil-off rate.

Also, your conversions are a little off. 19 liters if 5 gallons, not 6, so you're already starting with too little water.

The rule of thumb is to mash with a ratio of between 1.25 - 1.50 quarts of strike water per pound of grain. Expect the grain to retain 0.1 gallons per pound from your first runnings. When sparging, you'll get out the same as what you put in (because the grain is already saturated and will not absorb more water, and the "dead space" in the mash tun already has wort in it).

So, say you had a recipe comprised of 10 lbs of grain, and you wanted to end up with 5 gallons of wort. You'd prepare 12.5 quarts of strike water, to get that 1.25 quarts/lb ratio in your mash (I like to mash fairly thick). Your grain will retain 1 gallon of that water (0.1 gallons / lb). Say your mash tun has 2 quarts of "dead space," or space where the liquid will collect below your outlet port, and which will not drain out. That means your first runnings would be 6.5 quarts (12.5 quarts strike water, minus 4 quarts (1 gallon) grain absorption, minus 2 quarts (0.5 gallons) dead space in mash tun = 6.5 quarts, or 1.5 gallons).

If your boil-off rate is 1 gallon/hour, and you're going to boil for an hour, and you want to finish with 5 gallons of beer, then you can figure out how much sparge water you need. Say your boil kettle has another 2 quarts of "dead space." You need your pre-boil kettle volume to be 5 gallons (finished volume) + 0.5 gallons (kettle dead space) + 1 gallon (boil off in 1 hour) - whatever you already collected in first runnings.

In this example, your sparge water volume would be 5 + 0.5 + 1 - 1.5 = 5 gallons.

Or get BeerSmith. Once you've dialed-in your equipment configuration, it does all of these calculations for you automatically.

 

[McKnuckle]

Grain will absorb about 0.1 gallons of water per pound.

Great explanation by kombat. The only caveat I'll add is that if you use a bag to lauter (BIAB), absorption is typically less, in the 0.06-0.08 gal/lb range. And that's with just an extended gravity drain, not squeezing.

 

[DavidSwede]

Thanks for all the replies! Has helped a lot.

Just to say Kombat.... when I said the 19 litre bit it was that the ratio of starting quantity to finishing quantity was the same. I didnt mean that the amounts converted directly.

Basically I was going in using the starting wort volume as my original required volume.

A follow up question to this...

Do you make any attempt to 'squeeze' the grain or just let it drain out and thats that. And do you attempt at all to get the 'dead space' loss or again just leave it?

 

[kombat]

when I said the 19 litre bit it was that the ratio of starting quantity to finishing quantity was the same. I didnt mean that the amounts converted directly.

OK, but it doesn't quite work that way. Your boil kettle will boil off 0.8 gallons/hour (or whatever) regardless of whether it's a 3 gallon batch or a 15 gallon batch. Same thing with your mash tun - it will have 2 quarts of dead space regardless of what size batch you're brewing. You can't just scale everything like you did - you have to account for these constants.

Do you make any attempt to 'squeeze' the grain or just let it drain out and thats that.

No squeezing, I just drain. That said, the BIAB (Brew In A Bag) guys usually squeeze the bag to scavenge as much wort as possible from their grain, with no problems.

And do you attempt at all to get the 'dead space' loss or again just leave it?

Well you can't really get it - it's buried under several pounds of hot, wet grain. That said, I usually prop up the back end of my mash tun (rectangular cooler) to try and minimize the dead space and drain more of my wort from the mash.

With your kettle, you could minimize the dead space by using an autosiphon, or picking up the kettle and just dumping the last bit into the fermenter, or a couple of other ways. It's up to you, I guess. I end up with a couple quarts left in my kettle, because I whirlpool, and when the wort starts to get cloudy while draining, I stop, which leaves some liquid in the kettle with the hop gunk and trub.

 

[Pappers_]

The easy method is keep sparging until you hit the target you want for pre-boil. In my process, I need to start with 8 gallons pre-boil. I sparge until I get there. Then I stop.

 

[McKnuckle]

For BIAB, you have no dead space loss. The bag is lifted out, drained, and that's it. You deal only with absorption loss.

 

[dsaavedra]

The easy method is keep sparging until you hit the target you want for pre-boil. In my process, I need to start with 8 gallons pre-boil. I sparge until I get there. Then I stop.

I do the same with my batch sparge setup. I figure out how much strike water I need by using a ratio of ~1.5 quarts water per pound of grain (I play around with the ratio sometimes), mash for an hour, drain out as much first runnings as possible, check the volume of my first runnings, then sparge with my target preboil volume (usually ~7 gallons for 5.5 gallon batch) minus my first runnings volume (plus a little extra because I always seem to have a hard time getting out exactly how much sparge water I put in).