Leaf Hop Absorption

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captaineriv

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I have 2 questions for everyone.

1. Does anyone has any info or know where I can find a table that shows how much wort is absorbed by whole leaf hops. When I use hop pellets (all I've done in the past), I plan my mash/sparge water amounts so that I end up with 5.5 gal. of wort in the kettle after a the boil and 5 gallons in the fermenter, and I have always hit my target, give or take a very small fraction of a gallon. In my last brew, I used 1 oz. Challenger pellets and 2 oz. Fuggle leaf hops and came up at least a good half gallon short of my target.

2. From looking at the high-water (or high wort) ring in my kettle from before the boil as compared to the wort level afterward, I think more than my estimated 5% per hour evaporated out. Based on your experiences, what does everyone estimate their evap rates to be for a 5 gallon batch.

captaineriv
 
1) Based on a small sample, it looks like I'm losing about 1/2 gallon to hop absorption.

2) I'm losing about 1.5 gallons/hour to evaporation.
 
If that's the case for me, maybe I lost less water than I thought to hops and more to evaporation. For the quantity of hops I used (1 oz. Pellets and 2 oz. leaf), is it unrealistic to think that I'd lose much more than half a gallon, or might it be closer to a gallon. If I can seperate what I lost to hops as opposed to what I lost to evaporation, I can use Promash to pinpoint my expected rate of evaporation for next time so I can squeeze out about 5 more bottles per batch.

captaineriv
 
No way two oz. of hops would absorb more than a cup of wort. Bacisally, you are re-hydrating them and four oz. of water per oz. of hops is about all they'll take. You can always make up the volume after the boil with water.

It's not unusual to lose 1-2 gallons water in a 60 minute boil.
 
I agree, I usually run 6.5 to 7 gal of wort in the kettle as a pre boil amount and end up with around 5.5 or so in the fermenter. Take out the trub and I have my 5 gal or so. It depends on the yeast how much I lose in the fermenter. I have never tried to pin point it in Promash though I probably should, I tend to brew by the seat of my pants ( to use a flying expression.)
 
I'll plan more for evaporation losses next time. I would have added water but my OG was just barely where I wanted it, so I held off. Promash tells me my efficiency is somewhere between 65 and 70% and has been this for both of my AG batches.

Everything seemed good with my mash and sparge. I used 1.3 qts. per lb. of grain in the mash and about 2 qts. per pound of grain of sparge water. Mashed for 90 minutes. Temp. started out at 154 and was down to about 150 after 90 mins (I stirred the grains around about every 20 minutes to reduce hot spots). Then I sparged over the course of about 45 minutes with 168 degree water. I used a sparge arm for this. I evaluated my methods and decided that there are some things that might have reduced efficiency, but the question is, just how much?

1. Stirring the grain at 20-minute intervals during the mash: Should I do this or just leave things alone for the whole duration.

2. Ordered precrushed grain from NB and brewed the next week. Would milling my own significantly effect efficiency?

3. I use a 5-gallon round water cooler for my mash tun, so raising the temp to 170 for a mash-out is almost impossible. I go straight to lautering after conversion and recirculating.

4. Used 5.2 pH stabilizer but apparently used it wrong. People on another forum said to add at least some of the grist to the tun, add the 5.2 buffer on top of the dry floating grist, and then mix it in with the water. I dissolved it completely into my mash water before adding the grain.

With all that being said, what might help me bring efficiency up to 75-80%?

captaineriv


 
:ban:
captaineriv said:
1. Stirring the grain at 20-minute intervals during the mash: Should I do this or just leave things alone for the whole duration.

2. Ordered precrushed grain from NB and brewed the next week. Would milling my own significantly effect efficiency?

3. I use a 5-gallon round water cooler for my mash tun, so raising the temp to 170 for a mash-out is almost impossible. I go straight to lautering after conversion and recirculating.

4. Used 5.2 pH stabilizer but apparently used it wrong. People on another forum said to add at least some of the grist to the tun, add the 5.2 buffer on top of the dry floating grist, and then mix it in with the water. I dissolved it completely into my mash water before adding the grain.

With all that being said, what might help me bring efficiency up to 75-80%?

captaineriv


1. I'd just leave it. If it's mixed well to start with, you shouldn't develop hot spots

2. The efficiency depends very much on how finely the grain is crushed, but for brewing, you want a fairly coarse crush (which yields less sugars than a fine crush). Crushing too fine causes a bunch of other problems. I'm sure NB crush the grain just fine. It will go stale faster than whole grain, but a few weeks won't make any difference.

3. I bought a 5g cooler for mashing but had difficulty obtaining the required mash temperature. I find it much easier to mash in a 4g SS pot on the stove top (here I do need to adjust the temp) and then transfer it into the cooler for sparging. I can and do raise the temp for a mash out.

4. Never used it, but I find acidifying the sparge water makes a great difference to tannin extraction.

Other observations.

Why mash for 90 minutes? With 2 row, 60 minutes should be more than enough.

Sparging in 45 minutes is too fast. If you sparged more slowly, your efficiency would probably increase. (I usually take about 90 minutes.)

If you sparge with 170 degree water, by the time it has meandered through the tubing and out of the sparge arm, it will probably be several degrees cooler. You want the temp to be about 170 degrees after it exits the sparge arm.

Hope this helps.

-a.
 
That information helps A LOT. Thanks a lot. Two questions though. I use a sparge arm that is propelled only by the water passing through it. I have the water coming from my sparge tank just fast enough to even spin the arm and no faster. How would you suggest slowing things down using that arm? My other question is about the SS pot for the mash tun. I considered doing it that way but the only thing keeping me from doing it was the trouble. What's the easiest way to transfer the hot mash to the cooler without making too much of a mess or getting burnt? Would a small garden hand shovel do well for moving the grain? Thanks again.

captaineriv
 
There are two factors that control the sparge time:
1. The rate at which you add sparge water.
2. The rate at which you drain the wort.
I add the sparge water like you (just fast enough to spin the arm), but I reduce the outflow and when there is sparge water about 1 inch above the grain bed, I turn off the inlet to the sparge arm, then turn it on again when the water level drops below the top of the grain bed. It's as interesting as watching grass grow, but it works. :)

As for transferring from the mash tun, I add some foundation water to the cooler (to get about two inches over the false bottom), then use a 1 qt measuring jug to transfer most of the mash. For the last little bit, I just tip it in, then rinse the mash tun with a bit of sparge water, and dump the last few ounces into the cooler.

I brew in 5g batches, but I have to ask:
If you're considering using a garden shovel to transfer the grain, what size batches do you brew?:D

-a.
 
ajf said:
I brew in 5g batches, but I have to ask:
If you're considering using a garden shovel to transfer the grain, what size batches do you brew?:D

-a.

Haha. I meant the little hand trowels for planting small plants. Thanks for the sparge info. So far, I've done it by regulating the flow on both vessels so that the water level in the mash tun stays at a constant 1 inch above the grainbed. I'll definitely try your suggestion next time. Seems to make a lot of sense. I was hoping for at least a 1 hour sparge before it started but could only stretch it out for 45 mins.

captaineriv
 
ajf said:
If you sparge with 170 degree water, by the time it has meandered through the tubing and out of the sparge arm, it will probably be several degrees cooler. You want the temp to be about 170 degrees after it exits the sparge arm.

-a.

Just noticed this from earlier. What should I heat my initial sparge water up to so I can correct for losing a few degrees?

captaineriv
 
captaineriv said:
Just noticed this from earlier. What should I heat my initial sparge water up to so I can correct for losing a few degrees?

captaineriv

What's right for me isn't necessarily what's right for you.
I jammed my sparge arm so it wouldn't rotate and then fed water through the tubing onto a digital thermometer.
It took me about 5 exciting hours to determine that I was losing 10 degrees from the HLT to the outlet from the sparge arm.

-a.
 
To go back to the earlier part of the discussion, I lose 20-25% to evaporation during a 1hr boil. I believe this high rate is due to my 30qt ss pot being full to the brim when I start boiling and hence all the evaporation escapes to the atmosphere.

I recently acquired a keggle (sans fittings), so I'm hoping that the high sides and curved top will trap more of the evaporative losses and return the to the boil and reduce my loss to evaporation.
 
wow, 10 degrees sounds like a lot. I suppose it would help to maybe do a little experiment with this before the real deal next time.

captaineriv
 
Baron von BeeGee said:
To go back to the earlier part of the discussion, I lose 20-25% to evaporation during a 1hr boil. I believe this high rate is due to my 30qt ss pot being full to the brim when I start boiling and hence all the evaporation escapes to the atmosphere.

I use this same size ss pot. 20-25% seems about right for me, looking back. No where around where I had planned though. Thanks for your observation.

captaineriv
 
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