[KilroyWasHere]

Hi all,
This feels like a fermentation question, as opposed to equipment, apologies if it in the wrong category.
I cool my fermenting wort using a 4 inch diameter stainless coil (I forget the product name) immersed in the fermenter, like a smaller version of an immersion chiller. I pump cold water through it using a pond pump. The cooling water is in a 16 quart picnic cooler containing ice packs. Control is run on a Raspberry pi. I have readouts of the beer temp via a thermo well and the cooling water via a probe in the cooling water.
I am striving to get better yeast character is my beers. The two things that I feel could be culprits are yeast health at pitch, and yeast stress during fermentation. Since I routinely have water in the cooler that is 50F or cooler, I am wondering if pumping water that cold into the coil immersed in the wort can be stressing the yeast because the coil temp is potentially much lower than the beer temp. FWIW the fermentations finish in short order, so I don't think yeast is going dormant. I know there is a lot of forced convection going on during active fermentation so the actual temp of the coil while the pump is on is not clear. However, I also recognize that most cooling on the home brew and commercial scale is done on the exterior of the fermentation vessel.
I would be anxious to hear your thoughts on the topic. Thanks in advance.

[fredthecat]

what do you mean by "better" yeast character? what yeast and what temps are you hitting/believe you are hitting?

[KilroyWasHere]

what do you mean by "better" yeast character? what yeast and what temps are you hitting/believe you are hitting?

Particularly the Belgian strains (my LHBS carries WYeast) consistently seem to lack some or all of the advertised phenolics and/or esters. My control system allows me to hit and maintain any ramp or temperature profile I want. I can hold the beer temp within a degree either side of target. I'm trying to figure out if I need to look at my cooling process, or the general yeast health.

[denny]

what do you mean by "better" yeast character? what yeast and what temps are you hitting/believe you are hitting?

Particularly the Belgian strains (my LHBS carries WYeast) consistently seem to lack some or all of the advertised phenolics and/or esters. My control system allows me to hit and maintain any ramp or temperature profile I want. I can hold the beer temp within a degree either side of target. I'm trying to figure out if I need to look at my cooling process, or the general yeast health.

How much experience do you have with real Belgian beers? Could it be that you're expecting something that isn't supposed to be there?

[neuse]

Certainly the beer immediately at your coil will be cooler, but IMO the CO2 bubbles created during active fermentation would cause currents in the beer which would minimize this effect. Once the CO2 is no longer being generated, the beer is much less sensitive to temperature changes. I'm assuming you let the temperature rise after active fermentation is finished. No guarantees, but I think your temperature control is fine.

[CounterPressure]

Glycol chillers are used all the time by commercial breweries and they don't have issues with the coils being too cold. The beer doesn't mind.

Belgian yeasts typically produce more esters at warmer temps. So if you want more of that, don't cool so much. Stay closer to the upper end of the recommended range or even try above, and you'll definitely get more "character".  I'd be careful what you wish for though.

[denny]

Glycol chillers are used all the time by commercial breweries and they don't have issues with the coils being too cold. The beer doesn't mind.

Belgian yeasts typically produce more esters at warmer temps. So if you want more of that, don't cool so much. Stay closer to the upper end of the recommended range or even try above, and you'll definitely get more "character".  I'd be careful what you wish for though.

That last sentence is key.

[fredthecat]

without sounding cliched, there is definitely to trying a bunch of yeasts without stressing too much about highly specific fermentation temps and just getting ideas about which ones you like in a general sense. then spending some time focusing on that yeast or two and seeing how to treat it to create different things. im trying to do that nowadays a bit.

it all takes time and what works for one person wont work for another.

your cooling system sounds very interesting tbh, and i'd love it if you had pics or any explanation, even if yo point me towards a thread youve made about it if you have.

[KilroyWasHere]

Glycol chillers are used all the time by commercial breweries and they don't have issues with the coils being too cold. The beer doesn't mind.
...

Interesting to know, I thought the glycol chillers ran glycol through a jacket on the exterior of the vessel, but I have never actually seen one.

[KilroyWasHere]

...
How much experience do you have with real Belgian beers? Could it be that you're expecting something that isn't supposed to be there?

Fair question Denny. Assuming you are referring to tasting, not brewing, my experience is limited to what I can get here on the east coast. My favs are Chimay Red, Duvel, Saison DuPont, St. Bernardus Prior 8 & Abt 12, Rochefort 8 & 10, Piraat, Westmalle Tripel, LaTrappe Quad, Lachouffe. Never had any of those fresh in Belgium. 'Domestic' Belgians I drink are mostly Allagash white and Tripel, Oxbow Farmhouse beers, Ommegang 3 Philosophers and Hennepin, La Fin Du Monde (Canada I know), Golden Monkey.

[CounterPressure]

For newfangled ones like the X3 uni, yes that is true. But typically speaking I think it's far more common they just run through coils. It's a whole lot cheaper than building a double wall vessel.

[KilroyWasHere]

...
your cooling system sounds very interesting tbh, and i'd love it if you had pics or any explanation, even if yo point me towards a thread youve made about it if you have.

Happy to provide pics, thanks for asking. The overall system is below. If memory serves all of the parts less the fermenter cost under $150. There is a manually controlled heating pad strapped to the fermenter with velcro strips. It is controlled from the raspi via the hot relay. I drilled the lid of the fermenter for the thermowell on the left and the cooling coil on the right. A cheap 16 quart cooler has a couple of holes drilled for 3/8 tubing, duotight elbows to connect to the coil, duotight bulkhead fittings to fit to the lid. As you can see this is as sad fermenter, empty at the moment.




When I am fermenting, I button an old down vest around the fermenter, it is a perfect fit.





The thermowell and coil





A fish pond pump sits in the cooler, controlled by the raspi via the cold relay. a one wire temp probe sits in the water. The probes are typical of the kind you buy for raspi or Ardino. I swap frozen gel packs in and out of the water as needed.





The raspi controller manages both relays, has a web server so I can access via wifi to see the beer temp, water temp, target temp and the state of the relays. I can also set the target temp, so if I am ramping, I just have to bump the target temp up or down at the appropriate interval.

[KilroyWasHere]

For newfangled ones like the X3 uni, yes that is true. But typically speaking I think it's far more common they just run through coils. It's a whole lot cheaper than building a double wall vessel.

Ahhh I see that makes sense. Thanks I did not know that.

[CounterPressure]

That is a super cool setup you have there. I like it.

I'm not sure if you're familiar with this place or not, but I see you're using the solid state relays along with a couple other items that are often available at mpja.com.  I love that site!

[KilroyWasHere]

That is a super cool setup you have there. I like it.

I'm not sure if you're familiar with this place or not, but I see you're using the solid state relays along with a couple other items that are often available at mpja.com.  I love that site!

Thanks, I like what that site has to offer. I think I'll give them a try for the next project.