Batch sparge - good to the last drop?

Just curious, is it just me, or everyone?

When batch sparging, I drain my rectangular cooler mash tun directly into my boil kettle (which is already heating the first runnings). Once the line starts gurgling, I close the valve on my mash tun and remove the tubing.

I then prop up the other end of my mash tun (with the outlet/ball valve on the low end) and leave it for several minutes.

Then, I take a drink pitcher (the same one I use to vorlauf), hold it under the mash tun outlet valve, and open it up, draining more wort from the mash tun. At first, it flows freely, then eventually slows down to a trickle again. I close the valve and pour this into the boil kettle with the rest of the wort.

I'll repeat this 4-5 times, trying to get every last drop out of my mash tun, before finally spraying the grains down with cold water and disposing of them.

Does anyone else do this, or do you stop after the flow slows to a trickle the first time? Is there any potential drawbacks to attempting to collect every last drop of wort from the mash tun?

No problem doing that. I figure my volumes pretty close and only end up with a few cups of extra wort. I hang on to it in case my gravity is short and I need to add it to the pot but most times it goes down the sink

I usually leave something in the tun. Once the gravity falls below a certain point all you are doing is watering down your wort. Once the pH rises above a certain point you run the risk of extracting flavors you don't want. Every once in a while I have to tip the tun in order to get out enough for my boil and the gravity and pH are still good. This usually means I didn't add quite enough sparge water.

If what you are pulling out at the end still has plenty of sugar to make it worthwhile then it is fine.

I adjusted my volume to compensate for the loss you are recovering, because I am lazy.

cluckk said:

I usually leave something in the tun. Once the gravity falls below a certain point all you are doing is watering down your wort.

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My BeerSmith recipe printouts usually have a step that says something like, "top up volume to 7.25 gallons" in between mashing and boiling. I figured if I can drain a few more quarts from the grains while they're still at the right temperature, it's better to "top up" with water with even a few sugars in it than with plain old tap water.

cluckk said:

Once the pH rises above a certain point you run the risk of extracting flavors you don't want.

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Hmm, I hadn't thought of that. To be honest, I've never checked my pH at any step. I should probably invest in some test strips and see where my pH is at various steps of my brewing, just to get an idea of what steps might need a little tweaking.

I collect every last drop. Mainly for efficiency reasons, the last 0.5 gallon takes a while to drain out while tipped up to about a 30 degree angle. While the wort heats up on the burner I drain the last 0.5 gallons out.

I do the same as OP. I will drain the first/quick runnings into my pot and start it to boiling. I will then collect the slower dregs during the course of the next 15 mins or so, into a second pot or a pitcher, and just add to the boil kettle as I go along.

If I reach my boil volume at any point, I'll just drain whatever is left in the tun into a mason jar, and save that as starter wort for a future batch. (after checking via refractometer that I'm getting liquid of value).

negativereaction said:

If I reach my boil volume at any point, I'll just drain whatever is left in the tun into a mason jar, and save that as starter wort for a future batch. (after checking via refractometer that I'm getting liquid of value).

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I tried that once, and when I measured the gravity of the last of the runnings, it was only around 1.010. I figured I'd have to boil off 75% of it to get it to a gravity useful for starters, so I just dumped it instead.

kombat said:

I tried that once, and when I measured the gravity of the last of the runnings, it was only around 1.010. I figured I'd have to boil off 75% of it to get it to a gravity useful for starters, so I just dumped it instead.

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That's true as well. It's not often that the last drops are anything above 1.010 or 1.015, but on a larger grain bill, there's almost always enough left in the tank to put some good sugar water into at least one mason jar.

i do similar.. usually i don't want to wait too long because i do multiple batches on brewdays so sometimes i just add a little extra sparge water in the process so it comes out quicker.. may drop the sugar content a bit but i'm always around the preboil gravity that it is supposed to be so it seems to work that way

Yeah I do the cooler tipping thing but only once. I do a 2 step batch sparge...drain cooler, add sparge water, vorlauf again and drain. That last one is where I tip the cooler. For some reason, I don't get that last few quarts to drain otherwise. Doing this typically helps me nail me preboil volume and gravity. Might have to start doing that on the first drain actually. May notice a slight uptick in efficiency.

cluckk said:

I usually leave something in the tun. Once the gravity falls below a certain point all you are doing is watering down your wort. Once the pH rises above a certain point you run the risk of extracting flavors you don't want. Every once in a while I have to tip the tun in order to get out enough for my boil and the gravity and pH are still good. This usually means I didn't add quite enough sparge water.

If what you are pulling out at the end still has plenty of sugar to make it worthwhile then it is fine.

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This is good advice, if you are CONTINUOUS (fly) sparging. With a BATCH sparge, your pH will not change as you drain the mash tun- it's at whatever pH it's going to be since you've already added all the water you need. Drain that baby. Get every bit of sugary goodness.

You are right. I forgot we were talking about batch sparging.