Glycol

[brewpete]

Hi this has probably been asked before but can you use glycol in a maxi 110

[LeeH]

Yes but it’s safer to use food grade or cheap vodka.


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[Kev888]

Yes it works in the cool bath (to reduce freezing temperature). It thickens the liquid slightly so in higher concentrations can make any recirc pump's life a little more challenging, is about all.

Propylene glycol is safer around food/drink use, whereas ethylene glycol (typical car anti-freeze) is toxic so I wouldn't use that if there was the slightest chance of leaks or cross-contamination.

[Sorcerer]

Any solid dissolved in water depresses the freezing point, so dissolving salt or sugar in the water, will lower its freezing point, salt is more corrosive than sugar, the more solid you dissolve the lower the freezing point, up to a saturation point when it will not lower even though more solute is added, I think salt will bring the freezing point down to minus 6, and I'm sure sugar would be fairly similar. Probably easier to get your hands on than food grade glycol, and its also food safe.

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[brewpete]

Hi I can only get the fermenter down to 7c using the maxi with a cooling coil would using the glycol get it to drop any more

[Kev888]

The glycol reduces the temperature at which the cool bath freezes. It may then go a little bit colder by itself, but generally the use of glycol would be teamed with a different thermostat in order to set the bath temperature colder than standard. It depends how efficient the system is, but if you wanted the beer to be at 0c then the maxi bath would need to be somewhat colder - e.g. around -4c

Insulation of the FV and hoses is key in helping the efficiency (not just the immersion coil). As the coolant and beer get colder then they will suck in ever more heat from the air, trying to defeat the benefits. And whereas things may have been a bit prone to condensation before, with colder coolant it will be worse and can even start to freeze in some cases.

[orlando]

The glycol reduces the temperature at which the cool bath freezes. It may then go a little bit colder by itself, but generally the use of glycol would be teamed with a different thermostat in order to set the bath temperature colder than standard. It depends how efficient the system is, but if you wanted the beer to be at 0c then the maxi bath would need to be somewhat colder - e.g. around -4c

Insulation of the FV and hoses is key in helping the efficiency (not just the immersion coil). As the coolant and beer get colder then they will suck in ever more heat from the air, trying to defeat the benefits. And whereas things may have been a bit prone to condensation before, with colder coolant it will be worse and can even start to freeze in some cases.

With the odd leak, changing out hoses from the cooling coil e.g. and summer evaporation, means I'm always topping the cooling bath up. This has made me fight shy of using glycol even though it would be very useful in the summer. How can you keep track of the correct amount of glycol to water given the above? Is there a test for concentration levels?

[Kev888]

With the odd leak, changing out hoses from the cooling coil e.g. and summer evaporation, means I'm always topping the cooling bath up. This has made me fight shy of using glycol even though it would be very useful in the summer. How can you keep track of the correct amount of glycol to water given the above? Is there a test for concentration levels?

You can buy test strips and refractometers for measuring propylene glycol, though I never have. Not sure if one could use a brewing/sugar refractometer, perhaps it would be okay to check consistency - though obviously not to read out absolute glycol concentrations. (I've used hydrometers in the past for car antifreeze, but I don't think they work with higher concentrations of propylene glycol as the gravity doesn't correlate well with concentration).

Personally I just top up with the same strength as was in there to begin with. Evaporation will probably concentrate things over time, but for me that isn't really a problem (within reason) I just need to know it isn't getting less concentrated.

For the latest build though, like you I have only used water (in my case RO). It is just to maintain fermentation temperature so the cool bath is only set to about 16c. It is also for four FVs so the chances of leaks/losses is greater - not such a problem with water.

TBH I've rather gone off crash chilling the FV, I much prefer to let the yeast do their thing for longer and for the beer to become less green first. So if any chilling is wanted to help clear then my preference these days would be later on, e.g. in the keg. I half wonder if chilling the FV might be another influence from commercial brewing, designed to tackle requirements that homebrewers may not need to compromise over.

[orlando]

TBH I've rather gone off crash chilling the FV, I much prefer to let the yeast do their thing for longer and for the beer to become less green first. So if any chilling is wanted to help clear then my preference these days would be later on, e.g. in the keg. I half wonder if chilling the FV might be another influence from commercial brewing, designed to tackle requirements that homebrewers may not need to compromise over.

If your process focuses on clarity of final Beer, mine does, then chilling helps to deal with poorly flocculating yeast. The answer to that could be to choose a highly flocculent yeast and adjust your process to accommodate it. I've recently tried Wyeast 1099 that drops as clear as if it had been fined in the fermentor. Clearly (pardon the pun) if you want the character of a less flocculent yeast then you may have little choice than to chill if you're impatient. I think your point about commercial influence is valid. They need to produce Beer that is commercially acceptable and clarity, craft brewing excepted, is a factor. They also need to get it to the trade quickly for cash flow purposes, the two combining, forcing a solution that is unnecessary in home production.

[Kev888]

Yes, chilling can certainly help speed up clearing, particularly with awkward yeast and chill haze; the closer to freezing (without freezing) that one can get the beer the better, in terms of speed. My change in preference has been more about 'when' to chill, rather than whether to.

Chilling soon after fermentation pauses the yeast in their post-fermentation activity and removes lots of them before the work is complete. This sets things back so unless clarity is the only measure of beer quality then it can actually extend time to glass IMO. As homebrewers though, we have the beer within our control for longer, so these days my preference is to let the post-fermentation processes carry on normally, then deal with final polishing somewhat later.

By then the beer might be in a bright tank (or keg in my case) and so wrt this thread happens to remove need for very cold glycol chilling of the fermenter. I may chill the keg and/or fine it and/or filter it - though for styles that mature for reasonable periods the beer will usually become very clear naturally if allowed.

[orlando]

I don't believe the choices I make in my process, that focus on clarity, are detrimental to the overall quality, in my view they underpin it. Getting the mash pH wrong for example can mean tannins not binding to proteins properly, leading to issues beyond just clarity. Simmering rather than boiling, poor cold break, can all impact not just clarity. The pursuit of clarity can "fix" a lot of problems before they even arise. So many questions on here look for a fix rather than adressing the problem further up the process chain.

[Kev888]

Yes, there are lots of things that contribute to clarity and that go 'much' deeper into quality of the beer than aesthetics alone. To be clear (heh!) I'm not at all arguing against chilling - provided it is an addition to the process rather than an attempt to hide deficiencies earlier on. It is just that doing so prematurely, before the yeast have finished, isn't the optimum time 'unless' practical considerations force it.

Which they may of course, very little in brewing is entirely positive or without compromise. One reason it is done commercially is to clear even before fermentation is quite finished and then cask early without priming - another thing that is less suitable for many homebrewers.

[orlando]

One reason it is done commercially is to clear even before fermentation is quite finished and then cask early without priming - another thing that is less suitable for many homebrewers.

We have a local brewery that suffers terribly from diacetyl, it would be interesting to know how quick they turn on the attemperators.

[Kev888]

Crikey, that puts these subtleties into perspective. I'd hate to brew to tight schedules and turnovers, must be quite frustrating at times.

[orlando]

I understand that some people have a high threshold for perception of diacetyl with some incapable of detecting it. I wonder.....?