Mash one day, boil the next?

I was thinking about doing a brew over two days to free up some time on the weekend. The wort could sit in the garage overnight It's Wisconsin, it's winter so no problem. Does anyone know of any downside to this other than taking longer to get the boil going??

Thanks

Hi,
  The biggest problem would be the high chance of infection.  If you leave your unfermented (and unboiled) wort in the garage overnight a portion of it will start fermenting or spoil from wild yeast and bacteria.

Cheers,
Brad

Good point. The more I thought about it the less it seemed like a good idea.


Thanks
Mark

Just as a conversation point, how many bad flavors could develop in 24 hours (probably more like 16)?  An hour-long boil is going to destroy anything, so you'd be dealing purely with compounds created during that period between sparging and boiling.

I mean, a full pitching of large amounts of healthy yeast can result in full fermentation well inside of 24 hours (or 12, or however many you plan), but wild yeast or bacterial contamination is going to involve much smaller quantities of "bad guys."  I don't have any first-hand experience with this sort of contamination, so I really don't know how fast they move or how strong their flavor components are...

That's sort of what I was thinking. Especially since it's 34º in the garage right now. I probably wouldn't do it all the time but it would be convenient this weekend. I didn't brew because I didn't have the time either day but I would have time if I split it up. Oh well, I'd probably just end up making twice the mess. I came up with a good tip last batch. - Always make sure the drain valve on your primary fermenter is closed before staring to siphon from the kettle. Or at least position it so you can see it so you figure out that's something wrong before 2 gallons of wort ends up on the garage floor. Don't ask.

Mark

In The Home Brewer's Answer Book a similar question was asked on pg 391.  I won't retype the question or the answer here as they are both quite long.  However, the answer is somewhat interesting as a lot of things are addressed, such as the dryness of the beer and increased fermentability, using an overnight mash for souring the beer on purpose etc.  Long story short though, it is okay to do this but you really need a good insulated mash tun that won't lose very much of its temp.  You could start your mash, got to bed and sparge the next morning.  Your efficiency will probably rise and from what I can tell from his answer, light bodied, higher gravity beers may actually benefit from this practice.   

In food preparation the "danger zone" is between 40 and 140, and one is supposed to toss anything that has been in that range for over four hours - "when in toubt throw it out".  160 will kill most anything that wants to do you harm, but as someone who likes to mash at 145 knowing that 160 deactivates many enzymes,  I'd be reluctant to do an overnight mash and sparge/boil the next day. 
I actually tried it once and the next day my mash looked like a sourdough starter, all foamy and stuff.
The beer wasn't that great either.  I didn't get sick or anything being that it was soon boiled, but the wild yeast had had enough time to make their mark.

I wasn't thinking of mashing overnight. Just mashing and leaving the wort in the brew pot overnight to chill and be boiled the next morning. I would think leaving it in the mash tun overnight would turn into science fair project. Unless you had a way to keep it above 140º as MH pointed out.

I'm convinced. I'll check it off my Things to Try While Brewing list. Besides it''s more like 25º in the garage now and I don't want to start a thread the effects of freezing wort.

Thanks for all the input.

Mark

stoloma said:

I wasn't thinking of mashing overnight. Just mashing and leaving the wort in the brew pot overnight to chill and be boiled the next morning. I would think leaving it in the mash tun overnight would turn into science fair project. Unless you had a way to keep it above 140º as MH pointed out.
I'm convinced. I'll check it off my Things to Try While Brewing list. Besides it''s more like 25º in the garage now and I don't want to start a thread the effects of freezing wort.
Thanks for all the input.
Mark

Click to expand...

I had a very similar experience to Maine HB. I left the wort in the kettle over night and came back the next morning to begin the boil. Let me tell you, You NEVER want to smell that Smell! Good Lord it was bad. What do you do with 7G of bad wort? Down the drain it went.
If you want to make a lambic, that is REALY FUNKY, this is one way to start!
Cheers
Preston

I wasn't thinking of mashing overnight. Just mashing and leaving the wort in the brew pot overnight to chill and be boiled the next morning.

Click to expand...

That may work as long as it gets chilled very quickly. 
Keep in mind that at this point it has not been sterilized with a boil, so you have the potential for spoilage.

Personally I wouldn't do it.