Is there anyway to slow the rate at which the gravity drops during sparging? What has been happening is that I do not achieve my pre boil volume before the runoff gravity reaches 1.010. My sparge rate is right at 1 gal per 5 min and am not sure how to slow the rate down to achieve my pre boil volume.
Gravity During Runoff
- Thread starter alooper86
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Can you provide a description of your system topology? If you're fly sparging there's usually a way to control the MLT drain rate and the MLT fill rate, independently at least. I don't quite know how one would pull it off without that ability.
fwiw, I have a 3V2P single tier HERMs and fly sparge with an auto-sparge valve on the MLT. I set a one quart per minute rate using the valve on the output of the pump that is emptying the MLT and filling the BK, and the auto-sparge tracks that rate automagically and keeps the MLT filled to a set level.
Today I did a 10 gallon batch of a 72 point ale and hit the pre-boil gravity and volume dead nuts, but I've been using this system for a couple of years and have gotten it dialed into BeerSmith2 pretty well, so as long as I don't screw up things just come out per plan.
One could do the same without the auto-sparge valve, just need to match flows between the In and Out.
That can be tricky, though, hence the auto-sparge...
Cheers!
fwiw, I have a 3V2P single tier HERMs and fly sparge with an auto-sparge valve on the MLT. I set a one quart per minute rate using the valve on the output of the pump that is emptying the MLT and filling the BK, and the auto-sparge tracks that rate automagically and keeps the MLT filled to a set level.
Today I did a 10 gallon batch of a 72 point ale and hit the pre-boil gravity and volume dead nuts, but I've been using this system for a couple of years and have gotten it dialed into BeerSmith2 pretty well, so as long as I don't screw up things just come out per plan.
One could do the same without the auto-sparge valve, just need to match flows between the In and Out.
That can be tricky, though, hence the auto-sparge...
Cheers!
I'd say there is a good chance you are "channeling" in the grain bed. You should be keeping sparge water above the grain at all times for fly sparging and you control the drain flow rate to accomplish that. You also may have a problem with the design of the tun that exacerbates that.
If you cannot keep the flow rate good or this continues to be a problem, switch to batch sparging. You should see little change in efficiency and will avoid the problem completely.
I really don’t think channeling is the issue as I always keep about 2” of water above the grainbed and use a sparge arm that disperses water evenly. My mash tun is a brand new 20 gal spike brewing with their false bottom so I don’t think that is the issue either. As stated before, I keep my flow rate at 1 gal/5 min for the entire sparge as recommended.
LarMoeCur
Well-Known Member
Have you figured out your brew house efficiency? Without knowing more about your brewery, the processes, and recipe calculations. It sounds like you need to lower the brew house efficiency in your brewing software. If you are reaching 1.010 before pre-boil volume it's not a sparge issue. It's 100% a recipe issue. Either you are trying to collect more wort then the recipe calls for or your efficiency is below what the recipe calls for.
I’m not quite sure I agree with the issue being based on my efficiency. We reached 12 gal pre boil before we ended it due to going below 1.010. That pre boil gravity was 1.045. We were supposed to obtain 14.5 gal pre boil volume at 1.037. Had we added water to get to the required boil volume, our gravity would have been at the estimated number. So it looks as though we pulled off the sugars exactly as being calculated they are just dropping to quickly before we achieve our pre boil volume. We do run a single tier 3 vessel HERMS system.
LarMoeCur
Well-Known Member
The OP didn't say what your efficiency was. So, it sounds like your efficiency was higher than expected. 10 or 12 gallon batch? What is the MLT? Cooler or kettle? What went into the mash? How much water and grain? What was the intended volume of sparge water? Do you have ball valves on your pumps?
Could be you are sparging to fast or channeling. 1 gallons in 5 minutes. Is in the ball park of a good flow rate. If your intended sparge volume was around 8 gallons or more. Without knowing more details it's really hard to trouble shoot accurately.
MLT is a 20 gal stainless spike brewing kettle. 13 lbs MO and 3.5 lbs flaked barley and a handful of rice hulls. Strike water volume was 6.5 gal. Sparge water volume was 11 gallons and I do use ball valves on all fittings and pumps
chickypad
lupulin shift victim
It sounds like you're brewing a low gravity beer so oversparging can be a concern. If you're at your expected gravity then why don't you do just what you suggest, i.e. top off with water if you want a larger boil volume due to boil off? This will probably not be an issue for higher gravity beers with larger grainbills. BTW, what is your final batch volume that you're targeting?
Edit: just saw your additional post with the grainbill. I think are approaching 90% mash efficiency so this is not anything wrong. You just have a low gravity beer and good lauter efficiency so you need to top off with water.
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Smellyglove
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Your efficiency-numbers add up. Next time just add the missing water to the recipe and tweak it further from there.
We were brewing a 5.5% dry Irish Stout yesterday with a final batch volume of 10.00 gallons. It sounds to me through all of the posts that it may be a slight adjustment I need to make within my equipment setup and just need to add the water to top off to the estimated pre boil volume in the meantime.
chickypad
lupulin shift victim
So you're planning 4 gals of boil off? I think you need to turn your burner down, you'll definitely run the risk of oversparging with those variables. With my 20 gal pot I only get about 1.75 gal per hr boil off.
chickypad
lupulin shift victim
Pretty big trub loss, you need to account for that in the recipe. After boil and chill sounds like you are expecting about 12 gals, which would be a beer in the 1.045 range based on your initial target of 14.5 gals at 1.037. That trub loss is wort not straight water so if you are only calculating the recipe for 10 gals of wort you're going to short yourself on grainbill. Sounds like you were aiming for a beer more in the mid 1.050's, so your 14.5 gals preboil would need to be in the 1.046 range. Not sure which program you're using but I think you may not be figuring that right.
IndyBlueprints
Well-Known Member
I agree that 2 gallons of loss to trub is way too heavy. Do a search for Brewlosophy, and look for their experiment of adding all the trub into the fermenter. The result they came up with was one beer with no trub in the fermenter, and another beer with all the troop in the fermenter, there was no noticeable difference in flavor. Sounds to me like you’re wasting a lot of good wort. I brew 17-19 gallon batches at a time, and have less than 1/2 gallon of loss.
I don’t mind a bit of trub loss, usually it is a lot of whirlpool hops, and I want my fermentor full so for 15.5 gallons into fermentor so I aim for post boil, chilled wort volume of 17 gallons. Because chilled wort is about 4% lower volume than boiling wort I need about 17.7 gallons in kettle at end of boil. So for 2 gallon boil off I need 19.7 gallons at end of mash. The key number for figuring out the grain bill is the 17 gallons of chilled wort at end of boil. This needs to be at OG.
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