Bizarre experience: mash turns to milk

[darlacat]

Anyone know what might have happened here? Brewing a vienna lager this morning, mashing in with 60c strike water, and the wort turns milky instantly. Then the element in the mash tun (under a false bottom) scorched instantly and tripped out. Recipe was mainly Vienna malt, small amount of pils, bit of carapils and carafa for colour. My usual method for brewing lagers, and has never happened before!

 

[Agentgonzo]

Milkiness could be the starch in the wort.
It happens with mine all the time. As the mash progresses, the starch gets converted to sugar and the mash clears.
Possibly you had a finer crush and more flour this brew?

I've just this second mashed in on my brewday. Here is what it looks like

 

[darlacat]

Milkiness could be the starch in the wort.
It happens with mine all the time. As the mash progresses, the starch gets converted to sugar and the mash clears.
Possibly you had a finer crush and more flour this brew?

I've just this second mashed in on my brewday. Here is what it looks like
View attachment 95859

Yes, I used a 3kg pre-crushed bag of Vienna from Malt Miller, and am thinking the crush was too fine. Too much flour in the crush?

 

[Agentgonzo]

Yes, I used a 3kg pre-crushed bag of Vienna from Malt Miller, and am thinking the crush was too fine. Too much flour in the crush?

Probably. If it settles into the element, it'll insulate the element from the cooling power of the wort and could scorch, overheat and cut out. Give it more of a stir. As the mash progresses, the starch should convert to sugar, dissolve in the wort and it'll become clear like normal

 

[darlacat]

Probably. If it settles into the element, it'll insulate the element from the cooling power of the wort and could scorch, overheat and cut out. Give it more of a stir. As the mash progresses, the starch should convert to sugar, dissolve in the wort and it'll become clear like normal

I had to dump it all due to the scorching, unfortunately. Scorching was so bad it tripped the element, so couldn't perform a mash until cleaning it out. Will contact Malt Miller as it was clearly an issue with the crush and flour content of the bag of Vienna.

 

[MashBag]

Fine crush. Lots of milk colour and then a bung up which starved the element?

 

[Sadfield]

Process rather than the malt is the issue.

Mashing cold grains into 60°c water will have dropped the temperature below the gelatinisation temperature of malted barley, and also performed a protein rest. This will have released un-gelatinise starch and proteins into your wort, that then gelatinised when the temperature was raised (61-65°C), scorching your element. Much in the same way rice swells and the water goes more opaque when you heat rice.

 

[Agentgonzo]

I had to dump it all due to the scorching, unfortunately. Scorching was so bad it tripped the element, so couldn't perform a mash until cleaning it out. Will contact Malt Miller as it was clearly an issue with the crush and flour content of the bag of Vienna.

You could contact MM, but to be honest I don't think the malt is at fault. Sometimes the crush varies and sometimes you can get more or less flour in a bag, as it will settle a little in the big 25Kg sacks they get. They may have more input for you though.

Chalk it up to experience and stir the mash more next time so that it doesn't allow the element to scorch

 

[darlacat]

Yes, I think this was the issue

Fine crush. Lots of milk colour and then a bung up which starved the element?

 

[darlacat]

Process rather than the malt is the issue.

Mashing cold grains into 60°c water will have dropped the temperature below the gelatinisation temperature of malted barley, and also performed a protein rest. This will have released un-gelatinise starch and proteins into your wort, that then gelatinised when the temperature was raised (61-65°C), scorching your element. Much in the same way rice swells and the water goes more opaque when you heat rice.

I would have thought this on reading my post, but grain was at room temperature, and the water didn't get below gelatinisation temperature. Had two thermometers measuring temperature and it was fine.

Also, I've experienced a mash at under the gelatinisation temperature once before. A few years ago I was attempting a ferulic acid rest for a saison, and had the issue with grain below gelatinisation temperature. The mash turned to wallpaper paste! This didn't happen this time: mash at 62c, how I always start off lagers. When I drained off the wort for the vienna it eventually separated and I had an inch of normal wort at the top, and a solution of finely crushed flour beneath. Wort consistency was normal.

 

[darlacat]

You could contact MM, but to be honest I don't think the malt is at fault. Sometimes the crush varies and sometimes you can get more or less flour in a bag, as it will settle a little in the big 25Kg sacks they get. They may have more input for you though.

Chalk it up to experience and stir the mash more next time so that it doesn't allow the element to scorch

It was a 3kg bag of vienna.

 

[Agentgonzo]

It was a 3kg bag of vienna.

Yeah. But it depends how it was prepared.
If (if) TMM gets 25kg sacks of pre crushed malt, then there is a likelihood that it'll settle a bit in the bag (think if how the cornflake packet has the small dust particles at the bottom). If they happened to get your 3kg from the bottom of a 25kg pre-crushed sack, then it'll likely have more-than-average amounts of flour.

As I said, it's just guesswork - if any of my "if" statements doesn't hold true, then the entire postulation falls down

 

[Sadfield]

I would have thought this on reading my post, but grain was at room temperature, and the water didn't get below gelatinisation temperature. Had two thermometers measuring temperature and it was fine.

How could it have been if your adding c20°C to 60°C strike water, that's going to lower temperature, not raise it above 62°C?

You've releases starch from your grain husks before gelatinisation, then heated it, causing gelatinisation around your element.

 

[darlacat]

Yeah. But it depends how it was prepared.
If (if) TMM gets 25kg sacks of pre crushed malt, then there is a likelihood that it'll settle a bit in the bag (think if how the cornflake packet has the small dust particles at the bottom). If they happened to get your 3kg from the bottom of a 25kg pre-crushed sack, then it'll likely have more-than-average amounts of flour.

As I said, it's just guesswork - if any of my "if" statements doesn't hold true, then the entire postulation falls down

Ah, sorry, I understand. Misread your initial post.

 

[Agentgonzo]

Ah, sorry, I understand. Misread your initial post.

No worries. I didn't explain it very clearly

 

[darlacat]

How could it have been if your adding c20°C to 60°C strike water, that's going to lower temperature, not raise it above 62°C?

Strike water was heated above this temp in HLT, so water once mixed in with the grain in separate mash tun was at 62c.

 

[Sadfield]

Ah, sorry, I understand. Miswritten initial post.

 

[The Baron]

You could contact MM, but to be honest I don't think the malt is at fault. Sometimes the crush varies and sometimes you can get more or less flour in a bag, as it will settle a little in the big 25Kg sacks they get. They may have more input for you though.

Chalk it up to experience and stir the mash more next time so that it doesn't allow the element to scorch

Correct me if I am wrong do MM offer more than one type of crush for BIAB or AIO's etc

 

[Buffers brewery]

I've seen the same milkiness in the early stage of my mashes but it clears quite quickly. As others have said, probably starch that eventually converts to sugar and dissolves in the wort. As I circulate my wort through a HERMS I don't have the problem of scorching during the mash. Do you circulate the wort during the mash?

 

[Caramel Ox]

Pretty sure TMM crush everything to order from whole grains, so the husk/flour ratio won’t vary.