Longer Sparge - Better efficiency

I brewed a Oatmeal Cream Stout today. I planned to hit about 1.054 OG. I was kegging and bottling during the sparge, so I turned my valves down really low so that I could get the kegging and bottling done. I usually sparge for 45 minutes to an hour. Today's sparge went for about 1.5 hours.

Just took a gravity reading in the kettle - 1.067

That puts me at about 74% efficiency (according to Promash) when I am usually at 65 %. Thankfully, I hopped on the high side for that style (about 51 IBUS), but I hope that this beer is not too out of balance. I wanted a good session brew, but this one is going to be rather strong.

Could my longer sparge have accounted for my efficiency increase? I did everything else the same. If this is the case, I am going to start slowing down my sparge considerable.

BTW, here is the recipe I used today:

Oatmeal Cream Stout
9 lbs. 2-Row
.50 lbs. Crystal 40L
.50 lbs. Crystal 60L
.50 lbs Chocolate Malt
.25 lbs. Crystal 120L
6 oz. Oatmeal
4 oz. Black Patent
4 oz. Roast Non-Malted Barley
3 oz. Dextrine Malt
1 lb. Lactose (added with 15 min. remaining in boil)

.50 oz. Columbus (14%) (60)
1 oz. Kent Golding (4.2%) (60)
1 oz. Fuggles (4.0%) (30)

Mash - 155
Yeast - Nottingham

dumb question - did you take the gravity before or after adding the 1 lb of lactose?

When fly sparging, I get about 85% efficiency if I sparge for 90 minutes.
If I cut the time down to 45 minutes, the efficiency drops to about 75%.

-a.

Slower is better. It takes time for the sugar to dissolve.

rod said:

dumb question - did you take the gravity before or after adding the 1 lb of lactose?

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I took that reading after adding the lactose.

ajf said:

When fly sparging, I get about 85% efficiency if I sparge for 90 minutes.
If I cut the time down to 45 minutes, the efficiency drops to about 75%.

-a.

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What do you mean, "sparge for 90 minutes"? Isn't sparging just the process of rinsing the sugars from the grains? Do you really "sparge" for an hour and a half?

i sparged for well over an hour sunday with the high gravity brew...

slower is better for getting lots out, but it depends on your original grain bill...

sparging for 90 minutes from a standard gravity batch, might extract more than just sugars after a while...

yikes. That adds an hour and a half onto a 6-hour process.

Do you stir or otherwise move the grainbed at all during the mash or sparge?

aseelye said:

Do you stir or otherwise move the grainbed at all during the mash or sparge?

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I do not stir . . . but I do rake it. Sometimes I use the handle end of my spoon. I insert about 4 to 6 inches into the grain bed and gently rake through it. This eliminates channeling that may occur.

As for length of sparge - an hour is recommended. I usually go closer to 45 or 50 minutes because of impatience, but after seeing my efficiency on that last batch, I think the extra 25-30 minutes will be time well spent.

I don't. I add boiling water for mash out and stir, let it sit for about 15 minutes, then beging the sparge. From then on, no grain gets disturbed. It usually takes me about 45 min to sparge, sepending on the size of the garin bill. and I usually pull between 75-80% efficiency regularly so I now set my promash efficiency at 78 when formulating a recipe.

Last night was my first time sparging for 90 minutes and I went from 58% to 76%.
My new grain mill might of helped as well. For now on it's 90 mins for me.

Evan! said:

What do you mean, "sparge for 90 minutes"? Isn't sparging just the process of rinsing the sugars from the grains? Do you really "sparge" for an hour and a half?

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Yes when fly sparging.

The time isn't wasted as there are plenty of other things that have to be done.

-a

Both of my all grain batches I sparged until the hydro read 1.000. One time was 45 minutes and the other was about 55 minutes. Both of which ended up with my efficency at 70%. Could I have kept going if there was room in my brew kettle or is the gravity reading the most important thing to go by? I also need to reduce my mash temp, both times I was at about 160 degress.

Just be careful with fly sparging that your pH doesn't go too high. I haven't had any issues with it, but have read that increased sparge times on the fly you could be getting into a trouble area if you don't acidify your sparge water.

aseelye said:

Do you stir or otherwise move the grainbed at all during the mash or sparge?

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certainly. I see no reason not to. This ensures that there will not be any pockets of sugars stuck anywhere in the bed. Especially when you're doing batch sparging...stirring helps wash the entire bed.

Though, I've only done one AG...so what do I know?

You can't stir the grainbed during a fly sparge - if you disturb it too much, you'll get grain husks in your wort, the bed is acting as a filter. You'll have to re-vorlouf if you disturb it too much.

Batch sparging, yeah, stir it up well before you let it sit - you have to reset the grain bed before draining each time anyway.

the_bird said:

You can't stir the grainbed during a fly sparge - if you disturb it too much, you'll get grain husks in your wort, the bed is acting as a filter. You'll have to re-vorlouf if you disturb it too much.

Batch sparging, yeah, stir it up well before you let it sit - you have to reset the grain bed before draining each time anyway.

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But you can and should gently rake it to avoid channeling.

sonvolt, raking is an interesting idea; do you think it's necessary even if the sparge water drips or sprays randomly over the entire top of the grain bed, or if you keep a layer of water on top?

p

I'm curious... do any folks here with RIMS or HERMS type systems rake the mash? That's fly sparging, right? I thought one of the benefits to having the runnings recirculate was to set the bed. Seems that raking it would mess that up.

DrewsBrews said:

I'm curious... do any folks here with RIMS or HERMS type systems rake the mash? That's fly sparging, right? I thought one of the benefits to having the runnings recirculate was to set the bed. Seems that raking it would mess that up.

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Raking is not going to unsettle the bed. Note that I "gently" rake the bed . . . and only about 6 inches into my grain bed (I use a converted Gott-style cooler).

I'm not convinced that longer is better.

I usually batch sparge for ~30-45 mins., no more. My efficiency is usually ~75%; sometimes more, sometimes less. I recently heard Denny Conn on The Brewing Network and he said he sparges "as fast as possible" - he just opens the valve all the way and lets the wort fly.

I did this my very first couple of AG brews b/c I 'didn't know any better! I've been toying with trying the 'Denny Conn Method' again!

sonvolt said:

Raking is not going to unsettle the bed. Note that I "gently" rake the bed . . . and only about 6 inches into my grain bed (I use a converted Gott-style cooler).

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Ahh... so as long as you're only disturbing the top, say 60% of the mash, the rest does the filtering? One of my brewing buddies uses a large, rectangular cooler for mashing and raking 6 inches down would have been into the very bottom of the grain bed, hence my confusion.

Learn somethin' new every day here.

I've cut my sparge time from 90 minutes to 60 minutes and have found no difference.

it really depends on the grain bill imo... if you've twenty pounds or so of grain for a five or six gallon batch, i think you benefit from a long slow sparge... as well as a long boil.

zoebisch01 said:

Just be careful with fly sparging that your pH doesn't go too high. I haven't had any issues with it, but have read that increased sparge times on the fly you could be getting into a trouble area if you don't acidify your sparge water.

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Would hopping the sparge water lower the PH ? You ought to get pretty good hops utilization steeping it for 45-90 minutes at 175. The low ph might really help dissolve the sugars, without brewing the tannins out of the husks...

casebrew said:

Would hopping the sparge water lower the PH ? You ought to get pretty good hops utilization steeping it for 45-90 minutes at 175. The low ph might really help dissolve the sugars, without brewing the tannins out of the husks...

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Hmmm. I have heard talk lately of FWH (First Wort Hopping) and mash hopping (hops directly in the mash) and have wanted to give both a try. This is an even earlier addition.

I think that it would be really cool to do an Imperial IPA where the initial mash was hopped, the sparge water was hopped, and there were more hops thrown into the kettle as the wort is collected from the sparge. This would be a pretty hoppy brew even before the first boil addition.

It may actually be a waste of hops, though. A lot of it may be boiled out after such a long time. Also, I think I read somewhere that the human palate has a threshold of something around 100 IBUs. In other words, we don't even taste bitterness above this level.

As for the effects of ph on dissolving sugars, I need to study that . . . [leaves to find a book/website/etc.]

casebrew said:

Would hopping the sparge water lower the PH ? You ought to get pretty good hops utilization steeping it for 45-90 minutes at 175. The low ph might really help dissolve the sugars, without brewing the tannins out of the husks...

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I don't think the hops actually change pH, but from what I have read the pH will affect utilization. If my understanding is correct, temperature alone is not really responsible for utilization...for the most part...the mechanical (physical) process of boiling is the key. Now, the hops aroma can be infused but with the actual aa's I believe they rely on the action of the boil mainly to be released. At least that is what I have gathered. The equations are all based on boiling water. Now I am not saying you can't get bitterness from it, just wanted to point out that utilization tends to refer to the bitterness rather than the aroma I believe.

Rhoobarb said:

I'm not convinced that longer is better.

I usually batch sparge for ~30-45 mins., no more. My efficiency is usually ~75%; sometimes more, sometimes less. I recently heard Denny Conn on The Brewing Network and he said he sparges "as fast as possible" - he just opens the valve all the way and lets the wort fly.

I did this my very first couple of AG brews b/c I 'didn't know any better! I've been toying with trying the 'Denny Conn Method' again!

Click to expand...

Yeah, when batch sparging, I usually go as fast as my grainbed will allow while keeping clear runoff. I'm frequently in the high 70s low 80s. Let'er rip!



Longer might be better for fly-spargers though, but what a pain! Down with the fly sparge!