Fly spargers---do you drain your grain?

[guypettigrew]

When you get to the end of your fly sparging process---determined either by having collected your desired volume of wort or having reached your desired gravity for the runnings---are your grains still floating or have you allowed them to run dry?

My method is to do the latter, but I'm wondering if it's ideal.

An example. If I'm making a standard bitter with (say) 5kg of various grains then the volume of the mash liquor would be 12.5 litres (2 3/4 gallons). I then prepare about 21 litres (4 1/2 gallons) of sparge liquor. These volumes are as suggested in Graham Wheeler's "Beer Engine", and 21 litres is the maximum capacity of my current hot liquor tank. Bit lucky, that!

The run off from the mash is balanced with the run in from the HLT so the grains "float" during the sparge. However, once the HLT is empty this changes. I leave the wort running from the grains until no more runs out. In other words, the grain is as dry as it can be by the end of the sparge. This generally gives me about 28.5 litres (6 1/4 gallons) to boil.

So, is this technique OK, or should I prepare a greater volume of sparge liquor to ensure the grains are still floating when I stop the sparge at the 28 litre mark?

Thanks.

Guy

[floydmeddler]

I allow to run 'dry' too. Always have done and always will I reckon.

[fisherman]

I never let my floating mash run dry,when the tun drains I change the bucket under the tap to collect the late runnings, I may test them for gravity but rarely use them. I prepare 40 litres of liquor for a 27 litre brew and usually throw a litre or two away.
No problem.

[Stoat on a rope]

I let the runoff go until the water level has just dipped below the grain bed, then start the sparge to bring about half inch of water on the top of the grain bed.

My concern with running dry is loss of temperature in the mash tun but now I think of it it's probably unfounded as the heat sticks around in there pretty well. However I do notice a substantial drop in temperature in the grain bed and I like to get that up to 72 ASAP.

I would give run dry a go though and see if it improved efficiency, and I'm keen to know if anyone could testify to one being better than the other.

[vacant]

I think the only minor disadvantage of running dry would be that you might have collected more usable wort.

[Horatio]

No, I sparge until I have the volume required and as I always prepare a little more sparge liquor than I actually need, I still have some liquid in the grains. Not enough to float the grains but a few litres or so come out when I drain it before emptying into the compost heap.

[micromaniac]

i do as haratio said but use any excass to top up the boil with .thats if theres no tannins in it

[fego]

i let it run dry but check the gravity to make sure its what I want and stop if it gets too low.

[micmacmoc]

I keep sparging until the volume is reached plus a litre or two....then add some more water to the mash, but not all I have prepared and leave it til later. If the volume is then short and more extractables are available, then I add this to the wort to make it up. I've been tempted to put the unused mash into a demijohn as a yeast starter base....but then the possibility of tannins and what this would do to the yeast dissuaded me.

[Dennis King]

As it gets near the end I keep checking until is down to the required gravity. Turn off the sparge but keep running off. By not adding any more water the final running's should stay the same, in theory.

[micmacmoc]

Ah, that makes sense. then any boil off can be replaced by the hot sparge water. Quite right, ta!

[Stoat on a rope]

Disregard my last comment, I didn't read the question right!

I don't run dry, I turn off the tap once I have the required amount of runoff for the boil.

[Dr. Dextrin]

I normally sparge until I have the correct volume for the boiler. While the boil is on I then drain the mash tun, collect the late runnings and use them to top up during the boil. To ensure they get the same boil time as the main boil, they go in a pan on the hob over a low heat. The only time I wouldn't normally do this is with low gravity beers (say 1039 and below) where the late runnings have practically no sugar left.

Just recently, I've stopped collecting the late runnings and have noticed a drop of a couple of points in gravity. Possibly there are other causes (like different pale malt), but I'll be starting to use them again to see if that brings the gravity back up.

[weiht]

What are your concerns regarding this? I dont think there is much difference at the final stage of the runoff as to whether the grains are floating or dry. I run it dry because I pre-measure my volume needed, and dont want to waste water as well as have a heavy mash tun to clear out. Most of the superior sugars you want would have already been transferred to the kettle, so that very last bit isn't going to make much of a difference.

Am i reading your qns wrong?

[guypettigrew]

Hi weiht

You're reading the query right!

It just struck me the other day that perhaps a better beer would be produced by keeping the grains floating all the time and just stop collecting the wort in the boiler when there is the desired amount in there. I'd then allow the grains to drain, but discard these final runnings.

From the replies on here it seems people do it all sorts of ways, so I'm still not sure if there is a "best" way.

It would be great if the commercial brewers on here could let us know whether they run the grain dry and then boil all the run off.

Guy