Cold water sparge

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Kaiser

Kaiser

Well-Known Member
Joined
Nov 1, 2005
Messages
3,895
Reaction score
171
Location
Pepperell, MA
Who says you need to sparge with hot water to get good efficiency. I just did a batch sparge with cold water (single sparge, two run-offs) and hit 86% efficiency into the kettle. This is about what I got with the same recipe last time when I sparged with hot water.

Recently I have been doing more thinking about efficiency and I found no reason why a cold sparge should hurt when batch sparging if all your conversion is done during mashing and no further conversion happens during lautering. In this case I hit close to 100% conversion efficiency in the mash so there would not have been anything to be converted during the lauter.

The wort never cleared up though. I assume that this was basically cold break that formed due to the lower sparge temp

Kai
 
Kaiser said:
Who says you need to sparge with hot water to get good efficiency. I just did a batch sparge with cold water (single sparge, two run-offs) and hit 86% efficiency into the kettle. This is about what I got with the same recipe last time when I sparged with hot water.

Recently I have been doing more thinking about efficiency and I found no reason why a cold sparge should hurt when batch sparging if all your conversion is done during mashing and no further conversion happens during lautering. In this case I hit close to 100% conversion efficiency in the mash so there would not have been anything to be converted during the lauter.

The wort never cleared up though. I assume that this was basically cold break that formed due to the lower sparge temp

Kai
Click to expand...

Well, about about the talk that a hotter sparge helps efficiency by keeping the sugars more "fluid" and allowing more efficient lautering?
 
The water was from the tap. So it was at 54 F.

There is little change in fluidity in the 2nd and later runnings b/c they are lower gravity anyway. The main reason why a hotter sparge helps is b/c it causes more protein coagulation which increases the particle size and that improves the flow rate more significantly than a less viscous wort. But in batch sparging I don't really have to worry about that as long as it flows and even though I didn't time the run-off time it didn't seem to take longer than usual.

Kai
 
Here is the efficiency breakdown using my spreadsheet (http://braukaiser.com/documents/efficie ... ulator.xls)

file.php
 
Makes it quicker to bring the wort up to a boil if the sparge water is halfway there.
<Shrugs>
 
Cool. I think some people are just brewing gods with the magic touch. I'm betting Kaiser would come and brew at my house using the exact same ingredients and outdo my efficiency by 10-15%. I bow to you my lord.
 
Bizarre. Have you replicated it yet?

Sugars are known to be more soluble at higher temps. Lots of people have reported that a mash-out or hot batch sparge increased their efficiency. It seems logical that this is a likely mechanism for it. But your test (although unreplicated) suggests otherwise. But it DOESN'T explain the predominance of results by the masses. Any suggestions Kaiser?

Also, out of curiosity, is that a typical efficiency for you, or did it drop slightly?
 
FlyGuy said:
Sugars are known to be more soluble at higher temps. Lots of people have reported that a mash-out or hot batch sparge increased their efficiency. It seems logical that this is a likely mechanism for it.
Click to expand...

For a while now, my position on this has been that this is not a solubility problem. Even cold water can hold a lot of sugar. Just mix 1 cup of water with 1 cup of sugar and even at room temp the sugar will dissolve completely. It may take a little more time. And wort (even the first wort) is much weaker than that simple syrup. Once starch has been converted to sugar these sugars won't come out of solution and wait to be dissolved again by hot sparge water. Hot sparge water may speed up the process of leaching extract from the grits in the grain but the amount of sugar left in there is small compared to the sugar that is already dissolved in the sweet wort.

In my opinion there are other forces at work. I believe that brewers who see an efficiency jump when using hot sparge water cause more starches to be converted. I.e. they actually improved conversion efficiency and not lauter efficiency. For me the conversion efficiency was close to 100% and there was no room for change there.

But I don't think that this experiment will change the way I brew. There are still benefits to hot sparging. Getting to a boil faster is one of them and I haven't tasted the beer yet which means there can still be a surprise. But if this works and the beer is fine then I can see these pros:

- don't worry if you forgot to heat your sparge water
- BIAB brewers can actually sparge the grain in a cold water bucket.

But your test (although unreplicated) suggests otherwise.
Click to expand...

I'm not sure If I'm interested in repeating this anytime soon. There is so much more I want to try that may actually make a difference in my brewing.

Also, out of curiosity, is that a typical efficiency for you, or did it drop slightly?
Click to expand...

I generally get 85-87% on that size of a beer.

Kai
 
Kaiser said:
I'm not sure If I'm interested in repeating this anytime soon. There is so much more I want to try that may actually make a difference in my brewing.
Click to expand...
But that's the beauty of having this community -- perhaps others can give it a try and see what they get! That's even better replication because its independent. But I hear you.

Neat idea, anyways. Challenges the conventional wisdom -- typical Kaiser style!

:mug:
 
Kaiser, another question -- what was your liquor-grist ratio for this brew. You tend to mash pretty thin, don't you? I wonder if that had any influence on your results? (I.e. I wonder if a temperature difference would be more apparent to someone who mashes fairly thick, say at 1.25 qts/lb.)
 
Ok, so empirically my efficiency ALWAYS drops by 5-8% when I fudge my sparge temps on the low side. If I understand your hypothesis, it may be translated to "if a hot sparge boosts efficiency it is probably due to promoting continued conversion for at least part of the sparge". Is that what you're saying?

To flyguy's point, I mash around 1.5qt/lb which I'd consider in the midpoint of the range.

Certainly one easy way to confirm this is (and isolate only to sparge temp) to split the same exact mash into two lauter tuns and sparge each with the same volume of water, one cold, one hot and measure gravity.
 
I think Kaiser's observations are right on. The sugars are plenty soluble in cold water, heck look a LME! I think one issue is simple fluid dynamics. The water just flows better, which can be important in bigger beers.

I always wonder about flavor compound extraction versus starch conversion. Is one faster than the other? I'm very curious to see how your beer turns out. If the flavor is there, then flavor extraction is at least on par with starch conversion. If you find it lacks in the taste, this might indicate that extraction of the flavor compounds is a slower process that would benefit from more heat. One of these days I want to try an intentionally low efficiency brew to examine the affect on flavor. I'd use extra grain and just do a really quick mash so the OG is low, but I'm hoping the flavor compounds are quickly extracted from the grains. I'd use, say 2 extra lbs of base malt to get the same OG as I would from my normal recipe.
 
While sugars may be soluble in both hot and cold water, I don't think that is really the point. The solubility of sugar is directly related to temperature. Higher temperatures will necessarily dissolve more sugar, pulling them away from the grist and into solution more readily, which is a goal when sparging. The relevant question is how significant is this effect, and is it enough to make an appreciable difference in your measured efficiency to the kettle? That I am not so sure one.

Kaiser's results suggest no (but it was only one trial, and therefore might have been a spurious or chance event). Dozens of homebrewers have run the reciprocal trial (i.e. INCREASED the temp of their sparge water and seen their efficiency go up) to provide conflicting evidence.

Like Kaiser, I am curious why this can be. I suspect it may have more to do with the viscosity of the wort and the adhesion of those 'sticky' sugars to the grist, especially when one mashes fairly thick (say around 1.25 qts/lb). But it is likely a combination of many factors.

Kaiser -- why don't you move this to the Brew Science forum? I think this thread might get more attention there. And for anyone browsing the All Grain forum, they will still spot this topic.
 
Wow!! I mean, just wow! I only clicked on this thread because I thought it would have good comedy value. I almost fell off my chair when I saw that it was started by Kaiser.

This is a definite thread to watch from now on. Subscribed, prosted, rated and stapled to a passing hobo for future reference! :D

Oh yes! Why only batch sparging? Would it not be similar for fly sparging?
 
The mash thickness was 4:1 (4 l/kg or ~2 qt/lb) and I mashed in the kettle on the stove (Hochkurz: 63C,30min -> 70C, 40 min -> 76C, 15 min). There is a lot of stirring during heating and the long rest at 70 really boosts the conversion. I think that all the (good) flavor is extracted during mashing and present in the first wort. Sparging only rinses out the wort that is still clinging to the spent grain and it also leaches out undesirable compounds.

A viable experiment would be to take the spent grain after running off the first wort and put one sample into a paint strainer into hot sparge water and another sample into cold sparge water. let it sit for 10 min, strain and test the gravity. This should be done a mash that has close to 100% conversion efficiency and one that has only 70-80% conversion efficiency.

Bobby, you should gather the numbers necessary for my efficiency spreadsheet and see how much is lost in the mash and the lauter. I think that if there is significant conversion happening during the sparge the final sum should be more than 100% as some of the starches, that were considered lost after mashing, are actually converted and will show up as additional extract in the kettle and/or additional extract present in the spent grain.

Kai
 
An interesting experiment would also be to conduct a factorial design where one simultaneously manipulates the thickness of the mash and the sparge water temp. To do this, one could split a batch, and add more water to the second to increase the liquor-grist ratio. Mash both at the same temps, and at the end split each. Then do what Kaiser suggests, and put one sample from each in cold water, and the other sample from each in hot water. Check the gravity of each after 10 mins or so.

Treatments:
1. Thick mash, hot sparge
2. Thin mash, hot sparge
3. Thick mash, cold sparge
4. Thin mash, cold sparge

I would hypothesize that #3 would have the lowest gravity. The rest will probably be fairly close, I bet (borrowing from Kaisers results).
 
Kaiser said:
Who says you need to sparge with hot water to get good efficiency. I just did a batch sparge with cold water (single sparge, two run-offs) and hit 86% efficiency into the kettle. This is about what I got with the same recipe last time when I sparged with hot water.

Recently I have been doing more thinking about efficiency and I found no reason why a cold sparge should hurt when batch sparging if all your conversion is done during mashing and no further conversion happens during lautering. In this case I hit close to 100% conversion efficiency in the mash so there would not have been anything to be converted during the lauter.

The wort never cleared up though. I assume that this was basically cold break that formed due to the lower sparge temp

Kai
Click to expand...
I've read a bit on your site where you have proven that most of the standard published brewing assumptions are not necessarily true or have little merit.I too have a hard time believing that .004 crush difference would make someones eff. jump 25pts. or that 5degrees sparge water temp would have similar effects.
So,my question to you is--How do you approach technique to brewing different styles?Do you use the old (this is how your'e supposed to brew this style guidelines)or something entirely different?
 
RCCOLA said:
So,my question to you is--How do you approach technique to brewing different styles?Do you use the old (this is how your'e supposed to brew this style guidelines)or something entirely different?
Click to expand...

Most of my techniques are based on German brewing practices old and new. It is not that I’m not interested in other styles, I just want to keep my focus so I can go more in depth.

This being said, I’m a big proponent of understanding brewing techniques to a point where you can evaluate traditional and modern brewing techniques. To me it is important to understand why things were done in a particular way and why they may be done differently today. Some old techniques may have flavor benefits that you don’t get with the modern techniques but they have been abandoned in modern brew houses b/c they don’t fit in. But as a home brewer we are not bound by these restrictions.

While I’m a proponent of thin and stepped mashes I only push them for German styles. If you brew an English ale for example you should use an English malt with a thick single infusion mash. There might be a flavor difference that is part of the character of these beers.

I’m not a big fan of a one-size-fits-all approach unless your system really requires this.

Kai
 
Kaiser said:
While I’m a proponent of thin and stepped mashes I only push them for German styles. If you brew an English ale for example you should use an English malt with a thick single infusion mash. There might be a flavor difference that is part of the character of these beers.
Click to expand...
That brings up another interesting point. I wonder how much the gravity and fermentability of the wort play a role as well. I suspect that higher gravity brews, especially ones with a higher proportion of unfermentable sugars like some of the bigger English ales, might show a greater effect of hotter sparge temps.
 
From what I understand on the topic most home brewers need to use a heated sparge because when constructing their frankenstein sparge manifolds most understand very little about bluid dynamics and flow rates. Thus the hot sparge "loosens" the sugars from the grain and helps them flow more easily to the boil kettle. I have attmepted something similar with cold water and it seems that with pure dumb luck I have created a sparge mainfold that has excellent flow as my eff. has not suffered from the cooler temps. But, as stated, it then takes longer to get to a boil.

What does hurt my eff. when fly sparging is sparging way to fast. The grain bed then starts to channel and I miss a good deal of sugars.
 
Here's some more anecdotal evidence for the cold water sparge theorists... I didn't do a cold water sparge... just nowhere close to the normal...and go the best eff I've had yet... I mashed at 154, and sparge I could never get over 158. I got 80% eff... Thus the hot water to get the sugars has more damning counter evidence :). That being said, its just one guys experience, so YMMV.
 
Kaiser- how are you calculating conversion efficiency? I see the excel calc but im talking about doing so long-hand.
 
I think one of the key points is not to sweat your sparge water temperatures so much. "Relax, don't worry, have a homebrew" is vindicated yet again.
 
the results are in and I posted them on my brewing blog:

My Brewing Log | Cold Water Sparging

Conclusions:

* Cold sparging does not have strong adverse effects on efficiency and beer quality
* when a mash-out is performed it has no apparent effect on the fermentability of the wort. I don't know if this is still the case when no mash-out is done.
* it may make the beer more prone to haze
* it does not really save time since the wort at the end of the lauter will be colder and require more time to be heated to boiling temperatures
* it can save the need for a pot for heating the sparge water
* Since the spent grain temperature is lower at the end of a cold sparge less energy is wasted.
 
Nice write up Kaiser. Thanks for sharing your results.

One thing to note is that I see your mash schedule includes a mash out to 76 C (169 F). I know this has been debated earlier in the thread, but I still wonder if hot sparging would increase your efficiency slightly if you had omitted this step. Many brewers who perform single infusion mashes (particularly those using a cooler MLT and batch sparging) use hot sparge water in place of a mash-out. The collective experience on the board indicates that this makes a substantive difference in efficiency. I did notice that your efficiency into the kettle was slightly lower with the cold sparge techniques (perhaps not enough to be significant), but I do wonder if that difference would increase substantively if you were to skip the mash-out rest.

Regarding the cloudy wort from the cold sparge, that does seem a bit odd. With only one trial, it is hard to pin it to the cold sparge itself.

Anyways, interesting stuff. Thanks again.
 
FlyGuy said:
The collective experience on the board indicates that this makes a substantive difference in efficiency.
Click to expand...

My explanation for that is that there is still conversion gong on during the sparge which is accellerated by the hot sparge water. I doubt that skipping the mash-out and sparging cold would change the efficiency much in my experiment because I believe that the 99% conversion efficiency was already achieved before the mash out. I didn't test that because I generally don't bother to take mash gravity readings.

Kai
 
I know I am digging up an old thread here. Has anyone researched any further into this?

I think I may give this a try myself. Although i think I will use hot tap water. I have a hot water tank, where the water is heated off the boiler. Which I have tasted with no off flavors. If I can skip the heating of sparge water step, which I heat in my kettle. It will save me from having to juggle sparge water out and runnings into the kettle. As we as save me from having to be attentive to heating up that water and result in a more relaxed brew day.
 
My 2 cents.

Being a bit of a chemistry nerd, the concept of supersaturation immediately comes to mind.

http://www.ktf-split.hr/glossary/en_o.php?def=supersaturated solution

This definiation references salts but I think the same concept would roughly apply to sugars as we are talking here. The way to make a super saturated solution is to take a fluid, heat it, dissolve a substance in to the point of saturation, then let it cool. A solution at this cooler temperature would not be able to dissolve the substance in the same ratio as it could potentially hold at a hotter one. Thusly, the resulting solution is super-saturated. Even though it is initially in a fluid state, it could easily be turned completely solid by a catalyist such as a grain of sand. The bottom line here is that a hotter temperature in theory should help boost your efficiency, and a lower one would be less efficient. This is probably why the sparge temperature is hot rather than cold. On a home brewer's scale, the difference is probably pretty negligable. On the scale of a commercial brewery, where that difference translates into a bunch of dollars, it might not be so much.
 
Dr. Evil Backwards,

My most recent chem class was over a quarter century ago, so I am just guessing here.

At the temperatures and sugar concentrations present in a mash, would a warm water sparge actually force sugar out of solution and result in a lowered efficiency?

I may give this a try, I like streamlining the process in an attempt to be a reasonably succesful lazy brewer.
 
Wilserbrewer,

It's been a while since I had any chemistry either but I really liked it and never got to use it until I started AG brewing. :)

Since we're talking about sparging, you already drained most of your solution (in this case wort) when you were lautering your first runnings. I don't think the conditions in a mash are extreme to cause sugar to drop from solution. I was just using super saturation as an example of why hotter would be better than colder. It's been a long time but I think this was Le Chatlier's Principle. (? spelling)

I did a google on Solubility of sugars in water and found a good table to use as an example. It shows the maximum specific gravity of sucrose at different temperatures. I've adapted the data for use in this post.

(From Browne's "Handbook of Suzar Analysis")

0 Celcius 100 grams of water (Freezing)
SG 1.31490 at Saturation

25 Celcius 100 grams of water (Room Temperature)
SG 1.33768 at Saturation

80 Celcius 100 grams of water (Sparge water at approx 175 F)
SG 1.40493 at Saturation

100 Celcius 100 grams of water (Boiling)
SG 1.43594 at Saturation

Obviously you wouldn't want to use boiling water in your sparge, you'd get some nasty tannin extraction. Also, wort has more going on in it than just plain table sugar (Sucrose). If the goal is to get the best efficiency, using hotter water would definately be the way to go. Sucrose is the most soluable of the sugars, so don't go off these numbers and say (AHA I don't need to sparge with hot water). This example would only really be valid if you were pulling pure table sugar out of your mash tun. I would not want to drink that beer, lol.

:)
 
Clearly there is a difference, but look at those gravities. I understand that this is for sucrose, but even if the other sugars in wort are even half as soluble, you're still talking about a gravity of 1.15745 at freezing, roughly a point higher at room temp, and 1.202465 at 175F. This is based on maltose, etc being 50% as soluble as sucrose (which I completely made up, I don't know). I think as Kai proposed earlier in the thread, the water is not close to reaching the saturation point regardless so that is not the issue.
 

Similar threads

F
do you still need to heat sparge water if you mash out at 170 for 20 mins
Replies
13
Views
1K
passedpawn
passedpawn
oakbarn
"True" Sparge Volume.
Replies
5
Views
557
oakbarn
oakbarn
F
small sparge volume in an aio
Replies
15
Views
964
hiphoppotamuss
hiphoppotamuss
Denis2121
FG lower 5 points than expected
Replies
17
Views
531
Denis2121
Denis2121
T
Mash Volume Higher than Boil Volume eHERMS
Replies
5
Views
552
Town9
T

Latest posts

Back
Top