Using a counterflow chiller to pasteurize?

[videojunkie1208]

Was reading about pasteurizing low ABV meads, and was wondering if one could use a counterflow chiller (or a plate chiller?!) to heat mead to pasteurization temperatures by running near boiling water one way, and racking the mead the other way.

Questions are:
1. can you get the mead warm enough to pasteurize within the timeframe of a single run?
2. could you use a valve to control the flow to hold the temperatures like you do for cooling?
3. would you then need a second chiller to cool the now pasteurized mead back to normal temps?

Looking for a chemical free way to take care of killing the yeasts while maintaining flavor and such...

 

[RPh_Guy]

1. Yes, if you run the mead slowly enough it's certainly possible. However you need to maintain temp lower than ethanol boiling point, and you need to maintain that temp for a long enough time to effectively pasteurize, which is very difficult (or perhaps impossible) to measure.
2. Of course. However the mead would likely need to be pumped, which would present its own set of obstacles.
3. Yep, and both chillers should be stainless steel. $$$

You're better off sterile filtering IMO, or bottle pasteurizing. Or using chemical stabilization.

 

[videojunkie1208]

So, according to The Oxford Companion to Beer Definition of pasteurization
You'd need 30 seconds at 160°F (10° below the boiling point of ethanol) you'd have to play with your flow rates, but I am betting it wouldn't be that difficult to setup.

Pressure transfer from ss fermenter -> pasteurization plate chiller, -> longish loop of silicone tubing in a hot water bath, -> cold side plate chiller, -> keg.

Betcha with one of the coffee pot all in ones, you could set the temp to like 165°F, and recirculate the hot water through the pasteurization loop. Then loop a few feet of silicone tubing into the pot, dropping the other end into a 2nd plate chiller with cold water running through it.

Requires some thinking and maybe a test or three....

 

[videojunkie1208]

The other issue I see, is could pasteurizing cause any pectins to activate, causing issues with taste, clarity, etc.

 

[RPh_Guy]

Seems like you're off to a good start. If you can work out all the problems I'd love to see your setup.

I think you would need to control the flow with a valve on the fermenter, or at least somewhere between the fermenter and the first heat exchanger.

I also think you would need to use a rotameter on the way into the first exchanger in order to measure flow rate.

Don't forget the heater will need to be powerful enough to heat the entire batch to the desired temperature over the course of the the transfer.