BobbyM or FlyGuy: You Vs Palmer Sparge Water Temp

Bobby - After spending time trying to get me keggle setup going, I decided to try doing 5 gallon batches on my stove (since I have a cooler mash tun and a 8 gallon pot from my extract days). I refer to your write up on your web page (shameless plug Overbrook Brewery) for my technique.

On your site it says...

"Hot Sparge - Given that I skip the mash out infusion, I still want to raise the grain bed temp up into the 170F area. In most cases this means sparging with 180-185F water."

Whille heading to the forum to post this question, I noticed Flyguy had a sticky that generally said the same thing...

"• When batch sparging, the temperature of the mash-out and/or sparge water influence your extract efficiency. You want to make sure that either your mash-out infusion or your first batch sparge addition are hot enough to raise the grist to as close to 170 F as possible. This allows more sugar to be dissolved and reduces viscosity to facilitate easier lautering, both of which will improve your efficiency."

Palmer's HTB says on Page 203: "[...]Meanwhile, heat up your sparge water in the smaller of your two brewpots. You will need 3.5 gallons (13 liters) for the batch sparge volume. The water temperature should be less than boiling, preferably 165 to 175F. If the sparge water is too hot, the probability of tannin extraction from the grain husks increases substantially"

Without doing the math, I'm not sure that 175F (and definately not 165F) mixed in with a 152F mash is going to get the grain bed anywhere near 170F

Jumping back to page 181, he also says that sparge water should never be over 170. (So actually he even contradicts himself).

I'll back up Bobby and Flyguy here. For the longest time I kept my sparge water below 170. When I finally checked the grainbed temp, I found out it wasn't getting anywhere near hot enough. By bumping my sparge water up to about 190, my grainbed stabilized at around 168 on average and I notices about 5% increase in efficiency on a couple of batches.

I am neither one of these folks but I used beersmith to do some calculations. Here are the results:



It appears that it will work. I even recalculated it for 170 degree water...

^^^Mash temp and grain temp are two different things, after draining the tun you will lose a lot of heat, close to 10 degrees. I do a split batch sparge and hit close to 200f to raise my grain to the 168f to 170f range on the first split. I use the rest calculator here http://www.rackers.org/calcs.shtml.

I'll vouch for the hot sparging as well. Improved my efficiency with no noticeable change in taste.

I'm pretty sure Palmer is a fly sparger. To that extent, he is making the mistake of not clearly differentiating everything he writes between fly and batch. IOW, he's taking a mashout infusion as a given to get up to 168F first, THEN maintain with a 170F sparge temp.

Now, I don't have the print version, but take this page for example: http://www.howtobrew.com/section3/chapter17-2.html

He previously BRIEFLY touched on batch sparging but follows with the page I just reference. MOST of the info on that page is completely irrelevant and/or contradictory to good batch sparge technique, but he doesn't say so. Someone recently referred me to that page and asked me how one batch sparges AND still leaves an inch of water on top of the grain bed. Right.

Now, I will give him the benefit of the doubt and suggest that he could have been writing for AG novices and in that case, erring on the colder side just means lower efficiency. On the other side, too hot, means puckering tannins.

Agreed. This advice applies to fly sparging only. Batch spargers can sparge hotter.

In fly sparging, the top of the grainbed gets rinsed of sugars and other wort compounds much earlier than the bottom of the grainbed. This means that there is a pH gradient from the top of the tun to the bottom. At the top of the tun, the high pH is of concern because, when combined with hot water, it will promote tannin extraction from the grain.

In batch sparging, there is no such gradient to worry about and the pH of the mash is uniform. Thus, because there are no 'hotspots' of pH to worry about, you can get away with higher sparge temperatures. Higher sparge temperatures greatly increase lautering efficiency because they solubilize more sugars and reduce viscosity.

This is one reason why I entirely refute the outdated notion that batch sparging is 'less efficient' than fly sparging. I suspect that if you ignore the sparging 'rules' defined for fly sparging, like the one above, batch spargers can make equally high quality wort (or higher) and easily get the same efficiency (or higher) than fly spargers.

You have to take the age of the information into context. When Palmer wrote his book, he was using the accepted information at that time, fly sparging had an upper temperature limit for risk of tannin extraction, so batch sparging was assumed to as well. Since then people have found that you can use much hotter water with batch sparging because it doesn't play by the same rules as fly sparging.

It's not that Palmer is right or wrong, its that the information has changed. I'm sure in his next version, the technique will be updated

For batch sparging I actually think that it doesn’t matter much although I agree that there is potential for increased efficiency with a hotter sparge. Mainly b/c the higher temp can convert a little bit more starches.

I’m actually planning a cold sparge experiment in the future. Mash as normal (including mash-out) and sparge with cold water (50-60F). I think that it won’t make much difference for my efficiency just for longer heating times. I’m really curious if this will indeed be the case and if there will be a taste difference.

Kai

Wow, I appreciate all the replies. A lot of good information...

What exactly happens if you sparge lower in the 160170 area? Just, in theory a lower efficiency because you wont be doing enough to extract out the remainder of the mash?

janzik said:

Wow, I appreciate all the replies. A lot of good information...

What exactly happens if you sparge lower in the 160170 area? Just, in theory a lower efficiency because you wont be doing enough to extract out the remainder of the mash?

Click to expand...

The lower efficiency is the only defect I've noted.

I started cranking my batch sparge water to 180F-190F, too. Seemed scary at first but no ill effects.

Think of it this way, even if you fly sparge, the mashout is accomplished by infusing near boiling water to raise the temp to 168F. In batch sparging, you just use your sparge water to do the same thing and it's a lot cooler than boiling.

janzik said:

Wow, I appreciate all the replies. A lot of good information...

What exactly happens if you sparge lower in the 160- 170 area? Just, in theory a lower efficiency because you wont be doing enough to extract out the remainder of the mash?

Click to expand...

It is the efficiency that is affected by a drop in sparge temps to those values when batch sparging. The thing is not to let the grainbed temperture go above 168 - 170f.

boo boo said:

It is the efficiency that is affected by a drop in sparge temps to those values when batch sparging. The thing is not to let the grainbed temperture go above 168 - 170f.

Click to expand...

And you can even fudge that a bit if your pH is proper. I've found pH to make a much bigger difference than temp.