Cloudy after fermentation? All grain troubleshooting

[RoomWithABrew]

We might live opposite sides of this globe, but I think you know me better than that! Or ... to put it another way, which of my pH meters do you think might be mis-calibrated?

I find Slaked Lime is handy when I find myself putting in loads of bicarbonate. There seems to be a point when adding more bicarbonate becomes ineffective? Probably nonsense, I just start getting impatient, or else something in the calculator over-steps a mark?

Just checking how far your leg would stretch. The slaked lime changes pH a lot in the water calculator and doesn't add sodium I'd certainly use it if I had it.

 

[ThreeSheets]

Brewer: Todd Ashman,Titletown Brewing in Green Bay, WI​

... Fermentation is exothermic, which means it will create its own heat.
https://byo.com/article/fermentation-temperature-control-tips-from-the-pros/

I found a pretty cool presentation on this: Thermal Beispieltext Process Engineering for Brewers
On slide 36 there is a constant "𝑒 = 587 kJ/kg fermentable sugar"
Slide 38 equation 2 uses wort density, this constant and the overall wort density change to figure out how many watts of heat are produced and need to be balanced with cooling to stabilise the temperature.
If I get time I might derive at watts/time curve based on density/time and figure out the wort temperature jump above ambient temperature for air versus water bath.

 

[foxy]

I found a pretty cool presentation on this: Thermal Beispieltext Process Engineering for Brewers
On slide 36 there is a constant "𝑒 = 587 kJ/kg fermentable sugar"
Slide 38 equation 2 uses wort density, this constant and the overall wort density change to figure out how many watts of heat are produced and need to be balanced with cooling to stabilise the temperature.
If I get time I might derive at watts/time curve based on density/time and figure out the wort temperature jump above ambient temperature for air versus water bath.

But importantly as it states it depends on the temperature outside of the tank. Would be easy in a controlled atmosphere, harder to judge with temperature swings.

 

[ThreeSheets]

But importantly as it states it depends on the temperature outside of the tank. Would be easy in a controlled atmosphere, harder to judge with temperature swings.

Absolutely - if I can get a little predictive model going, I could estimate the wort temperature based on weather and wort activity. What I'm planning on doing is developing a thermal model to predict my requirements.

Concerning temperature swing; take this study on the internal temp of a shipping container, high thermal inertia means much less of an internal temperature swing. The thermal response can be predicted using a thermal time constant to be determined:

For air and water - the density and specific heat capacity differences are enormous: 1.22kg/m3 versus 1000kg/m3 and 1005J/kg/K versus 4200J/kg/K (these values sit on the numerator of the fraction). The only thing air has going for it is the convection coefficient being lower as air is quite insulative.

So if I put it in water the temperature swing is much smaller. In my water bath last time I had a time constant of about 3 hours - I was only getting about 2 degrees rise after work and then I would just swap a litre or two of the water with fridge cooled water.

I need to figure out how the house responds to the weather, and how the water bath responds to the house temperature, with that and yeast activity as a heat source I might be able to have something just good enough avoid an expensive cooling system.

Probably all of that deserves a separate thread - if I get around to doing this I'll post it about it - maybe write a bit of code or a spreadsheet for others to give it a try.

 

[foxy]

Absolutely - if I can get a little predictive model going, I could estimate the wort temperature based on weather and wort activity. What I'm planning on doing is developing a thermal model to predict my requirements.

Concerning temperature swing; take this study on the internal temp of a shipping container, high thermal inertia means much less of an internal temperature swing. The thermal response can be predicted using a thermal time constant to be determined:

For air and water - the density and specific heat capacity differences are enormous: 1.22kg/m3 versus 1000kg/m3 and 1005J/kg/K versus 4200J/kg/K (these values sit on the numerator of the fraction). The only thing air has going for it is the convection coefficient being lower as air is quite insulative.

So if I put it in water the temperature swing is much smaller. In my water bath last time I had a time constant of about 3 hours - I was only getting about 2 degrees rise after work and then I would just swap a litre or two of the water with fridge cooled water.

I need to figure out how the house responds to the weather, and how the water bath responds to the house temperature, with that and yeast activity as a heat source I might be able to have something just good enough avoid an expensive cooling system.

Probably all of that deserves a separate thread - if I get around to doing this I'll post it about it - maybe write a bit of code or a spreadsheet for others to give it a try.

It will make life a lot less complicated if you got a fermenting fridge. You should be able to pick something up Buckshee, or at very little cost.

 

[ThreeSheets]

Hi All,

So after having a few of this batch, I can say for a bizarre beginning it turned out alright. It did finish fermenting and didn't explode in my face. It took a good long time to settle out but it does have at least some degree of clarity:

That surprised me to see it settle after a couple of months, so I guess the moss worked alright, but I think the residual haze is due to the poor cooling coil this hot summer, not a very good cold break, and thinking about it earlier I also reduced the flow rate through the coil to save on water... maybe that wasn't the best idea.

The separated stuff that didn't come out in filtering + single fermentation is very present at the bottom of the bottles:

So to stop this happening again, I think I'm going to go with an exchange to a secondary fermentation vessel just to stop some of the yeast and sedimentary crud coming though. I don't usually get this much though. I may consider gelatin after that if I'm not getting success.

The final bits I learned from this one:

• When you try to make a beer that everyone will be happy with, it comes out BORING. It tastes neat and clean, leans malty with no bitter. This could have definitely done with more interesting grains and either some aroma boiling stage or some dry hopping added in.
• The attenuation of the Empire Ale yeast was terrible, partly from me not hydrating it and partly what I saw online. I might start going with more secure dry yeasts even though that limits the options, for anything else I think I'll hydrate beforehand.

Thanks for the advice everyone! Instead of cold crash equipment, I'm going to look into a cooling sack and shove a lot of bottled ice in it prior to bottling. Will consider something more expensive in the long term if we get more space... most of my time, space and sleep is being consumed by a newborn atm...

 

[An Ankoù]

@peebee
Sure your pH meter is calibrated correctly and temp corrected. I rarely have added anything to raise a pH, I'd like to get some slaked lime for adjusting water profile for kegs of carbonated water, but it's really difficult to get here and I'm not sure the airline would take kindly to me slipping some into my suitcase. Have to find a friendly chemist in an academic unit or commercial place.

It shouldn't be difficult to get hold of, you can buy food grade calcium hydroxide on amazon UK. It even has an e number.