Labor day water/grain ratio experiment

[r2eng]

In an effort to really nail each aspect of my brewing, I have begun a series of tests on my AG system to see where I can get improvements in process and repeatability. This weekend was the water-to-grain ratio on the mash.

I have read many posts and many books discussing the best ratio, and have boiled it down to the following (sorry, had to say it):

IPA test, OG 1.075
Batch #1 Session IPA Sr.: 1.25 qt/lb @152F, for 90 min., double batch sparge at 169F, collect 7 gallons of wort. Efficiency: 72%

Batch #2 Session IPA Sr.: 1.5 qt/lb @152F, for 90 min., double batch sparge at 169F, collect 7 gallons of wort. Efficiency: 88%

RIS test, OG 1.100
Batch #1 Stone Clone RIS: 1.25 qt/lb @152F, for 90 min., double batch sparge at 169F, collect 8 gallons of wort. Efficiency: 62% (ouch)

Batch #2 Stone Clone RIS: 1.5 qt/lb @152F, for 90 min., double batch sparge at 169F, collect 8 gallons of wort. Efficiency: 83%

Although a bigger boil pot would help IMMENSELY, it is obvious to me that the higher water-to-grain ratio helps.

I guess this is logical, fits in with other threads on the topic, but I just thought I would share.

 

[imherb]

Did You let it rest the entire 90 min. or did You stir one or more times? Thanks in advance.

 

[r2eng]

Stirred every 30-min.

That's how I was learned

 

[bob1852]

thanks for posting.

I too have been using 1.25 qt/lb and thinking that my efficiency (especially conversion efficiency) is suffering a little.

Although I do question you calling a 1.075 OG IPA a session beer

 

[jasonsbeer]

Cool experiment.

Many recipes call for a 60 min rest. Do you think 90 mins would be better? I assume longer rests produce a higher efficiency.

What problems might be associated with longer rests, aside from keeping the temp?

 

[r2eng]

Well, the 1.075 was the reason for the experiment!

Last time I brewed it, I had 72% EFF. This time, I had to tweak the temp into the mash due to a bad thermometer (long story). This made me add more water to compensate. after the mash I had 88% ... so I whipped up another batch and did the 1.25 qts/lb, and repeated the 72%.

I had to brew my IPA from Ed Worts' IPA contest again, with improvements, to try to improve it from the excellent comments given. The 88% efficiency made the beer a bit bigger! 1.075 is the top of the scale, but still in style.

 

[z987k]

so did you do 1.5qt/lb and then more sparge water as well for a total runnings that is greater in volume than the 1.25qt/lb or did you lower the sparge volume to keep the runnings the same volume?

 

[r2eng]

I dropped my sparge water volume... used Beersmith to calculate the absorption rate of the grain.

If I were to repeat this experiment, I would check the SG of the first wort in both sessions, and then each sparge. I haven't practiced engineering in awhile, so my scientific method suffered here . Maybe next time! This was more of an "accidental experiment"!

I think I am going to buy a bigger boil pot. My current 8-gallon one is a bit tight, especially on the bigger beers like the RIS's.

 

[annasdadhockey]

Do you think the same would hold true for fly sparging?
I know, I know, do your own damn experiment.

 

[Synovia]

This is one of the reasons why I have such an issue with the recommendation for 5g coolers. A 5g cooler essentially forces you to mash <1.5qt/lb for any grain bill above 10 lbs.

(you only have about 4.6g in a 5g igloo round cooler. The lid is counted as volume)

 

[r2eng]

Not sure about fly sparging, but I think that the increase in efficiency is due to the mash, not the sparge. It should still hold true. I feel a bit silly not measuring the pre-boil gravity of each step (mash, sparge #1, and #2).

FWIW: I use an Igloo Extreme 48quart cooler with a CPVC manifold.

 

[bob1852]

Well, the 1.075 was the reason for the experiment!

I'm not complaining - I make my IPA's in that range, and drink them like session beers. When I'm bottling a new batch, I get a little confused at the end

 

[r2eng]

Well, I certainly didn't complain about the larger OG! I just plan on doing a heavier dry-hop.

I know what you mean, though. My taste for bigger beers just moved my session definition a bit bigger, too.

Right now my house absolutely brims with the smell of hops!! I love it when 20 gallons of beer ferments. Makes me feel like a new dad again!

 

[z987k]

Cool experiment.

Many recipes call for a 60 min rest. Do you think 90 mins would be better? I assume longer rests produce a higher efficiency.

What problems might be associated with longer rests, aside from keeping the temp?

No, a 90 minute rest will not produce higher efficiency if the starches are already converted. A 90 min rest is usually used at lower mash temperatures because of the slower enzymatic activity.

Longer rests for normal mash temps mean wasted time essentially. If you are mashing low and go for longer, then you will end up with a more fermentable wort.