Batch Sparge Technique Question

So, the guy at the LHBS said to hold your mash for 15 minutes, not 45? What is mash #2? What is your efficiency with your process?

 

The first technique is a pretty traditional batch sparge, absolutely nothing wrong with that.

It's likely that with today's malts, a mash doesn't need to last 60m in order to convert all the starches into sugars. Depending on a couple factors - mash temperature and grain bill, mostly - conversion can be done in as little 15m or maybe even less. So it sounds like the LHBS is telling you to give it a shorter rest and is also sizing the runoffs slightly differently.

And really, this is probably going to come down to preference and comfort. Have you been making beer you like? Do you like your current process? You're going to get beer either way. Kind of strange for the LHBS to hear your method and insist on a different one, though.

 

I batch sparge closer to this way....

1.5 quarts of water per pound of grain
mash for 60 minutes (on average.... sometimes 75 or 90 depending on how fermentable I want the wort to be)
at the end of the 60 minute mash, I stir it for maybe 30 seconds to 1 minute
vorlauf for 5 minutes to allow the grain bed to set again (I recirculate with a pump)
collect 1st runnings (original mash water volume - 0.13 gallons per pound of grain)

note: usually takes 5-10 minutes to collect the runnings (roughly 7 gallons)

sparge with volume equal to (or maybe 0.25 gallons more than) my intended 2nd runnings collection goal

note: I try to hit 170F wort temperature after batch sparging. I brew 11 gallon batches and usually have to add 190F sparge water to accomplish that.

hold my wort at 170F for 10 minutes to "mash out"
at the end of my 10 minute mash out, stir the wort for maybe 30 seconds to 1 minute
vorlauf for 5 minutes to allow the grain bed to set again (I recirculate with a pump)
collect 2nd runnings to reach target preboil volume

note: usually takes 5-10 minutes to collect the runnings (roughly 7 gallons)

 

I'm sure someone who knows better can be more accurate, but I recall reading that the vast majority of sugar extraction happens in the first 10-15 minutes of the mash. It seems, then, that what your LHBS is recommending is more of a way to speed up your brewday than anything else. It doesn't seem like it would make better (or worse) beer than any other method, but is more efficient time-wise.

As with everything in homebrewing, just do what you are comfortable with. There is no one right way to do things - if you are happy with the efficiency that you get from your current method, then by all means keep doing it. An LHBS that tells you that you are doing something wrong when you are following a pretty standard method for batch sparging is kind of a dick, IMO.

 

Your LHBS technique is driven by recipe volume (grain weight) as opposed to outcome (pre boil) volume, so that's a difference. However, I think your technique is somewhat recipe driven as well, my understanding is that the "first mash" is really where all the fermentables come from anyway. I use a technique pretty close to your technique.

The 2nd technique is going to give you far more volume on the second mash, which I wonder will impact outcome because I'd be concerned that the increased volume going through the mash/grains offers greater opportunity to pull off tannins and such. Plus, if you're short any volume, you'd add it to the boil pot, which waters the whole thing down.

 

Why do you stir before your first runnings?

I typically just mash for 60 min
I don't stir
vorlauf and take my first runnings out
I add 1/2 of my sparge water @ just below boiling temp to raise the grainbed up to 170
I stir and let it sit for about 5 min
vorlauf/runnoff
Add my second half of the sparge water (175F)
Stir and let sit for 5 min
Get my kettle on the burner to heat it up quicker
vorlauf/run my last runnings into a pot that I add to the main kettle about 15 min later.

I think it's important to remove your first runnings before adding any more water. This helps rinse the grainbed with more fresh water.

 

This is probably true for conversion (under most conditions) from starches to sugars/dextrins, but there's more to mashing than conversion. An iodine test may imply that you're done, but in fact, some of those sugars/dextrins are still being broken down into simpler sugars. This is why longer mash times result in a more fermentable wort.

 

HM's basic double-batch sparge technique follows:

Complete mash
Re-circulate until runnings clear
Run-off into boil kettle
Apply heat

Sparge #1 (equal sparge volume hot enough to raise grain bed temperature to 168°F)
Re-circulate until runnings clear
Run-off into kettle #2
Apply Heat

Combine 2nd running with 1st in boil kettle
Continue heating

Sparge #2 (equal sparge volume hot enough to raise grain bed temperature to 168°F)
Re-circulate until runnings clear
Run-off
Apply heat
Add 3rd runnings to 1st and 2nd runnings

Go to throttle up!

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With a little practice, Sparge #1 water can be ready as the 1st runnings finish and Sparge #2 is ready to go when Sparge #1 is done.

 

I do just about exactly what you've been doing, except that I don't bother mashing out the first 'batch.' I just drain the tun, then add ~190F water to bring the second batch to ~168F. Stir the mash thoroughly (the point being to rinse the grains), and let it sit about 10 minutes, during which time I put the first runnings on to boil. Vorlauf, add the second runnings, and you're off.

It's definitely possible to mash for shorter periods of time than one hour, but I wouldn't go as short as 15 minutes. I know there are guys who do 25 minutes, do an iodine test, and often find they're done. I've never tried this, because it seems like extra hassle without much payoff, but if I was really pressed for time I might give it a shot.

 

I think the iodine test is of very limited value. It tells you nothing about the fermentability of the wort, so it doesn't tell you that you should stop the mash. Well, maybe if you're trying to get the most possible unfermentable dextrins...then I guess the iodine test could be useful.

 

You do a batch sparge with mashout. Many say that most conversion takes place fast and opt for shorter mashes. I will typically do the first stage for 60 min. I typically don't do a mashout any more, but will entertain the idea of a decoction mashout if it seems appropriate to the style.

There are many good ways and many bad ways to do a mash. I don't see anything wrong with the way you described.

 

My thought was to aid getting as much sugar into solution as possible.

 

After stirring and sitting for an hour or so, your water had probably absorbed as much as it can. It doesnt hurt it, but probably isnt necessary. It is good to do it after the sparges because you generally dont give it as much time to absorb the sugars.

 

Then, along those lines, would you conclude that the main reason a fly sparge generally extracts more sugar than a batch sparge (for this exercise, let's forget about other variables like kettle geometry) be because the rate of lauter is slower with a fly sparge?

 

The reason fly sparging has higher efficiency than batch is because the wort left behind in the mash tun is more dilute than with batch sparging or no-sparging. It's because of volumes and concentrations, not speed per se.