Plastic and Maximum Temperature

[wherestheyeast]

I bought a 3 gallon better bottle a while back and saw a warning to not exeed 140F liquid. My hot water is probably at or above 140F, so I'm nervous about what I'm doing to the plastic, or if I'm leeching chemicals from it, when cleaning. Does anyone have any experience with temperature of liquid and plastics? I'm not that interested in anecdotal evidence, but more curious about the scientific side.

So this also got me thinking about water coolers (or coolers in general) as mash tun. Is it really safe to use as a mash tun (with sparge temps reaching 170F)?

I know some of you have been using cooler mash tuns for years, but what is happening to the plastic? I know I can just use stainless, but I'd really like to find out some specifics on the matter.

-WTY

PS -- I had a conversation with a chemist a while back (before my brewing days) about cooking food in plastic containers in the microwave. He doesn't do it: the chemical (molecular?) structure of the plastic & food changes & who knows what effect that has you.

 

[gandalfiii]

Microwaves do not change the chemical structure of your food anymore than cooking with any other heat source. Many dieticians, in fact recommend cooking with microwaves because the nutrients are better preserved in foods when cooked with a microwave. As for the plastics, I don't really know. I'm pretty sure that the coolers are generally made of a more tolerant plastic than most plastic bottles and are preobably less likely therefore to leach into your beer, but I can't say for sure.

 

[JJL]

It all depends on the type of plastic you use. There are a number of different types of plastic. The term plastic is very generic. You can have PET, polycarbonate, HDPE, LDPE, polystyrene, PVC, etc. These are all plastics. In general, you aren't worried about heat as it relates to leeching. Heat will eventually melt the plastic. Each type of plastic has a different melt point. If your Better Bottle says 140F max, then it probably starts losing stuctural integrity at temps a little above that.

IIRC, the rough max temps are as follows,
PVC - 170F
CPVC - 200F
Polycarbonate - 250F
HDPE - 250F
Silicone - 400F

 

[jaytizzle]

I highly doubt that your hot water for residential use exceeds 140°F. Typical household water heaters are set to 120°-125°F as this is getting to the threshold of risk of injury/burns and also the proper temperature for dishwashers and hot water fed washing machines. When you cross that 125°F mark then you run into trouble. Human skin burns in about 5 seconds at 140°F.

Additionally, a quick search turned this up:
https://www.homebrewtalk.com/f11/6-gal-better-bottle-primary-fermenter-43774/index2.html

The link basically says that at 167°F that the better bottle will begin to soften.

 

[gandalfiii]

I have scar tissue from a 3rd degree burn on my foot that I suffered from running hot tap water on my foot when I was 3 or 4 years old. I don't know what the actual temp of that water was, but it was hot enough. Now that was about 30 years ago and I'm sure things are a bit safer now but it may be possible for his tap water to be quite hot based on my experience. Not to gross anybody out but my water was hot enough that when my mom pulled my sock off the skin on my foot came off with it. So pretty hot.

 

[wherestheyeast]

I get 140F+ out of the faucet -- I have my water heater cranked; big house with a lot of demand; I can't stick my hand in the water. I do have anti-scald device on my bathtub.

What material(s) are coolers made from? We they made (or approved?) for the purpose of holding 145F+ temps for 60-90 minutes?

So, does leeching occur independent of heat?

 

[TyTanium]

...So this also got me thinking about water coolers (or coolers in general) as mash tun. Is it really safe to use as a mash tun (with sparge temps reaching 170F)?

I know some of you have been using cooler mash tuns for years, but what is happening to the plastic? I know I can just use stainless, but I'd really like to find out some specifics on the matter...

The "is a cooler safe?" debate has been discussed frequently and thoroughly here. There are plenty of threads containing excellent info.

Each brewer must decide for him/herself.

And remember, in many cases, "safe" isn't binary...there's a scale and there are tradeoffs.

 

[gandalfiii]

I beleive that most of the coolers are made from #2 plastic or HDPE which according to wikipedia can withstand continuous temps of 230 F and up to 248 F for shorter periods.