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Re-pitching with fresh sediment from my Dubbel: Lalbrew Belgian-style Wit. I put about 500ml in… who knows how many cells 🤣

Sounds like a few of us are doing Wits at the moment; maybe lets do a collaborative swap when they’re ready?

@Agentgonzo
I'll be happy to do that, but I won't be brewing it for a month as the fermenter will be tired up for the next 3 weeks with my grand cru
 
Apologies this is a bit geeky, but just as a future reference for myself here's a detailed view of the response to a mash step from 55 to 63 degrees.

The 'kettle' trace shows the temperature of the water in the outer circuit of the heat exchanger, and the 'wortometer' trace shows the temperature of the recirculating liquor immediately before it goes into the spray arm.

Depth of the grain bed is about 14cm. It's interesting to see how much of a temperature difference there is between the top and bottom of the mash for about 5mins during the step; but the lower parts of the grain bed should get the same overall exposure to different temperatures by the end of the mash.

I set the recirculation temp a little high initially to accelerate the rate of temperature change:

View attachment 98580

And here's the corresponding step from 63 to 68 degrees:

View attachment 98581


Possibly of interest @Buffers brewery, @DocAnna
OOhhh that's brilliant, do you happen to know the recirculation flow rate as a proportion of total fluid volume or mass? I'm thinking this could lead into some scaling factor of expected ramp times for temperature change. 😍.... oh and what's wrong with being Geeky 😜
 
OOhhh that's brilliant, do you happen to know the recirculation flow rate as a proportion of total fluid volume or mass? I'm thinking this could lead into some scaling factor of expected ramp times for temperature change. 😍.... oh and what's wrong with being Geeky 😜
Yes indeed!
  • recirculation flow rate 1.9L/min
  • total fluid volume (before grain absorption) 15.15L
  • grain mass 4.45kg
  • diameter of the mash tun 33cm
  • dead space 2L
The mash tun was closed at the top, and there was about 1.5cm liquor standing on top of the grain :cool:

What surprised me was how much the droplets cool down between leaving the spray bar and arriving at the surface of the mash. High surface area to volume ratio?
 
I have a brew lined up before then, and the ferm fridge is currently out of use for a lager, but may be able to squeeze in the Wit and ferment at room temp by the end of May.
I'll be happy to do that, but I won't be brewing it for a month as the fermenter will be tired up for the next 3 weeks with my grand cru

No rush, gentlemen :-) plenty of time

Anyone else who fancies joining is welcome... @DocAnna ?
 
Well after today’s brew my stock levels are now definitely the best they’ve been.

In order of brewing:
  • Münich Helles (drinking - about half left)
  • Bière de Garde (conditioning)
  • Belgian Dubbel (conditioning)
  • London Bitter (fermenting)
  • Belgian Wit (fermenting)
That’s all kegs in action for the first time ever!
 
No rush, gentlemen :-) plenty of time

Anyone else who fancies joining is welcome... @DocAnna ?
Why my fine gentlemen, shall we call it dubbel or quits...I'm in.

[EDIT ... just to emphasise I'm not referring to betting, as I don't do gambling, not my thing.... I don't even enter the lottery]
 
Last edited:
Yes indeed!
  • recirculation flow rate 1.9L/min
  • total fluid volume (before grain absorption) 15.15L
  • grain mass 4.45kg
  • diameter of the mash tun 33cm
  • dead space 2L
The mash tun was closed at the top, and there was about 1.5cm liquor standing on top of the grain :cool:

What surprised me was how much the droplets cool down between leaving the spray bar and arriving at the surface of the mash. High surface area to volume ratio?
Just spent far too long working out things that were probably more obvious than I thought. I made several assumptions about the grain bed mean average temperature, that for the first 6 minutes your heating element was providing 0.71 kW to your mash, and in the next 5min 0.39kW, the equivalent energy flux to the body of the mash was 0.65kW and and 0.36kW respectively. Interestingly this means your mash was warming at about the same pace as the boiler was replacing the energy transferred to the grain. This is intuitively right but interesting to see. However because these are point estimates at 6 and 11 minutes, the energy flux declined as the temperature differential reduced, which also makes sense but makes working out an estimated ramp time an exercise in graphical calculus... and I do have limits on where it's worth going with this. I'm guessing I could estimate the thermal conductivity of the grain but
 
This is intuitively right but interesting to see. However because these are point estimates at 6 and 11 minutes, the energy flux declined as the temperature differential reduced, which also makes sense but makes working out an estimated ramp time an exercise in graphical calculus... and I do have limits on where it's worth going with this. I'm guessing I could estimate the thermal conductivity of the grain but

Probably could draw it 99% accurately and read back off that (cheating I know).

If there had been a 8 or 9 minute data point excel would have calculated the slope (another cheat). 😁
 


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