Is it normal for the grains to swell big time during mash out?

[Smellyglove]

For the entire duration of the main rest, I have a very nice grainbed, with about two inches of water on top.

When I raise the temperature for mash out the grains swell so much that there is no water on top whatsoever anymore. The grains eat up all that extra water.

I haven't been able to find much info about this topic. Is this normal? I'm mashing with 3L/kg. I know of people who mash with as little as 2L/kg without having this problem at all.

 

[Yooper]

I've never heard of that happening, so I would say it's highly unusual.

Where does the water "go"? Is the grainbed compacting due to using a pump or something? I can't imagine the grain puffing up much- it absorbs some water, but not enough that it gets puffy.

 

[Smellyglove]

If the grainbed would compact too much, wouldn't that leave me more water on top of it if it doesn't get stuck?

This has happened every single time on the new setup, 5 brews.

Yes I'm using a pump feeding a herms-coil.

 

[Thesomeguy]

If the grainbed would compact too much, wouldn't that leave me more water on top of it if it doesn't get stuck?

This has happened every single time on the new setup, 5 brews.

Yes I'm using a pump feeding a herms-coil.

Are you accounting for the water in the herms Coil when doing water Calculations? Depending on length of lines and the herms coil itself I could see maybe thinking that the grains have swollen when in reality the water has been moved.

 

[Smellyglove]

Are you accounting for the water in the herms Coil when doing water Calculations. Depending on length of lines and the herms coil itself I could see maybe thinking that the grains have swollen when in reality the water has been moved.

Yes. The 3L/kg is amount of water in direct contact with the grain at all times. The amount of water to grain ratio within the whole system is greater than this to compensate for deadspace, tubes and coil.

I recirculate the whole time, so the water doesn't actually get moved (from the mash tun).

 

[Smellyglove]

Will it in any way hurt to choke the pump to the BK completely for the first part of sparging so the grainbed gets covered again and then try to maintain that level? I'll lose some temp since I have to open the lid to verify the level, but other than that?

 

[pjj2ba]

For the entire duration of the main rest, I have a very nice grainbed, with about two inches of water on top.

When I raise the temperature for mash out the grains swell so much that there is no water on top whatsoever anymore. The grains eat up all that extra water.

I haven't been able to find much info about this topic. Is this normal? I'm mashing with 3L/kg. I know of people who mash with as little as 2L/kg without having this problem at all.

Something strange is going on. As the mash proceeds, the starch is being consumed and the amount of solid material in the mash tun should decrease. At the end of the mash, all that should be left is the husks and little bits of embryo. These should not be swelling when you mash out.

Is the grain bed simply lifting/floating up? I don't recirculate during the mash, but when I add water from the HLT, I add it from undernearth via my manifold. This causes the grain bed to lift up. I stir it to break it up

 

[patthebrewer]

I've never had that happen. Could it be that there is more water in your MT due to a slower flow during recirculation at mash out(possibly a grain buildup in your outflow), and what your seeing is in fact grain floating, instead of bulking up as you say???

 

[Smellyglove]

Something strange is going on. As the mash proceeds, the starch is being consumed and the amount of solid material in the mash tun should decrease. At the end of the mash, all that should be left is the husks and little bits of embryo. These should not be swelling when you mash out.

Is the grain bed simply lifting/floating up? I don't recirculate during the mash, but when I add water from the HLT, I add it from undernearth via my manifold. This causes the grain bed to lift up. I stir it to break it up

I havent actually measured the height of the grainbed before/after what I reckon is swelling. But, all of the water I start the mash with is still within the system, and the grains do look bigger, puffy-ish.

I add water from the HLT with a hose, just like the Blich autosparge but without the the actual autosparge.

 

[Smellyglove]

I've never had that happen. Could it be that there is more water in your MT due to a slower flow during recirculation at mash out(possibly a grain buildup in your outflow), and what your seeing is in fact grain floating, instead of bulking up as you say???

I've stuck my finger down in the mash, and it didn't feel like they were floating. It's dense. Just like you boil spaghetti with the lid on, the spaghetti swells and take up more room, all the way down.

When I open one of my dump-valves to check clarity of the wort it seems a bit more sluggish-flowing than during the start of the mash.

This is my last nut I have to crack in my new system which is awesome comparing to the last one I had, so I just hope this headscratcher can be solved. I've read some places (not even brewing-forums) that the grains swell with higher temperature, but if I'm the "only" one having this problem amongst homebrewers I must be doing something wrong.

 

[Smellyglove]

I don't know if this has anything to do with it, but I got my grains crushed at another LHBS today and this issue didn't happen at all. Did nothing differently.

 

[fartinmartin]

Were the grains used by the original poster crushed at all ?

 

[Smellyglove]

Were the grains used by the original poster crushed at all ?

Yes they were.