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General Category => Extract/Partial Mash Brewing => Topic started by: BP79 on December 07, 2011, 09:53:50 PM

Title: Full boil on stove-top: pre-heat "top off" volume
Post by: BP79 on December 07, 2011, 09:53:50 PM
I'll be making my first partial mash this upcoming weekend, have a new 8-gallon mega-pot, and would like to take advantage of finally being able to do a full boil.   Since I'll be doing this on a stove top that takes forever, I'm concerned about lag time after sparging, topping off the pot with another 4.5 gallons, and getting the volume up to a boil.

Would it be ok, at some point while the mash is resting for the hour, to simultaneously get the additional 4.5 gallons to a boil, or at least warmed up to my sparge temperature?  I just feel like something weird will happen post-sparge by 'cooking' everything for so long before ever getting up to a boil before I add the rest of the fermentables.  Any thoughts would be greatly appreciated.   
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: a10t2 on December 07, 2011, 10:00:49 PM
That should work, but if you're going to be boiling on the stove I wouldn't even try to do a full boil. It's a waste of energy IMHO, and depending on your stove it may not even be possible.
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: bigchicken on December 07, 2011, 11:49:51 PM
I'd have to agree. Boiling that much on a stove will either take forever or just not happen.  Invest in an outdoor propane heater and you won't be sorry.
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: euge on December 08, 2011, 01:21:18 AM
I also agree. See no appreciable difference between a full and partial boil. Sometimes expediency and ease of a concentrated boil outweighs the risk of the Maillard reaction.

That being said I also do full boils on my stovetop in my 80qt. Fits over two burners and I can bring 8 gallons to a boil fairly easily.
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: BP79 on December 08, 2011, 02:00:56 PM
I live on the 4th floor of an apartment complex in a rather urban area, so unfortunately I don't have the option of using a propane setup without doing something very stupid and/or illegal on the patio.  I'll do a test run tonight just to get a ballpark time of how long it'll take and to see if it's even possible.  That being said, the pot fits perfectly over two burners, so who knows.   
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: bo on December 08, 2011, 02:09:33 PM
Something you might try is to put the kettle in your oven, assuming it will fit. Get it to a boil and then place it on a burner to finish. The oven heats the entire pot, so you don't risk burning or caramelizing the wort during heatup. I would recommend putting a remote sensor in the wort so you know when it approaches boiling, so you can get it out of there before it boils over. I set my oven at 250F for food, because I'm not in a hurry. Not sure what to set it for with wort, but I would suggest starting around 300 -350.

I've never done this with wort, but I do it all the time with pots of food that I need to cook for long periods of time. It beats having to keep stirring to keep the food from burning on the bottom of the pot.
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: jeffy on December 08, 2011, 02:52:51 PM
Something you might try is to put the kettle in your oven, assuming it will fit. Get it to a boil and then place it on a burner to finish. The oven heats the entire pot, so you don't risk burning or caramelizing the wort during heatup. I would recommend putting a remote sensor in the wort so you know when it approaches boiling, so you can get it out of there before it boils over. I set my oven at 250F for food, because I'm not in a hurry. Not sure what to set it for with wort, but I would suggest starting around 300 -350.

I've never done this with wort, but I do it all the time with pots of food that I need to cook for long periods of time. It beats having to keep stirring to keep the food from burning on the bottom of the pot.

Brilliant!  I never thought of that.
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: rjharper on December 08, 2011, 03:13:30 PM
Something you might try is to put the kettle in your oven, assuming it will fit. Get it to a boil and then place it on a burner to finish. The oven heats the entire pot, so you don't risk burning or caramelizing the wort during heatup. I would recommend putting a remote sensor in the wort so you know when it approaches boiling, so you can get it out of there before it boils over. I set my oven at 250F for food, because I'm not in a hurry. Not sure what to set it for with wort, but I would suggest starting around 300 -350.

I've never done this with wort, but I do it all the time with pots of food that I need to cook for long periods of time. It beats having to keep stirring to keep the food from burning on the bottom of the pot.

Brilliant!  I never thought of that.

I would not want to try to lift a pot of 8 gallons of boiling wort out the oven and onto a stove top.  That's asking for a trip to the ER with scalds...
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: bo on December 08, 2011, 03:15:28 PM
Something you might try is to put the kettle in your oven, assuming it will fit. Get it to a boil and then place it on a burner to finish. The oven heats the entire pot, so you don't risk burning or caramelizing the wort during heatup. I would recommend putting a remote sensor in the wort so you know when it approaches boiling, so you can get it out of there before it boils over. I set my oven at 250F for food, because I'm not in a hurry. Not sure what to set it for with wort, but I would suggest starting around 300 -350.

I've never done this with wort, but I do it all the time with pots of food that I need to cook for long periods of time. It beats having to keep stirring to keep the food from burning on the bottom of the pot.

Brilliant!  I never thought of that.

I would not want to try to lift a pot of 8 gallons of boiling wort out the oven and onto a stove top.  That's asking for a trip to the ER with scalds...

Good point, but a lid placed on the top will prevent splashing. Works with a fairly large pot off soup.
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: rjharper on December 08, 2011, 03:23:04 PM
Something you might try is to put the kettle in your oven, assuming it will fit. Get it to a boil and then place it on a burner to finish. The oven heats the entire pot, so you don't risk burning or caramelizing the wort during heatup. I would recommend putting a remote sensor in the wort so you know when it approaches boiling, so you can get it out of there before it boils over. I set my oven at 250F for food, because I'm not in a hurry. Not sure what to set it for with wort, but I would suggest starting around 300 -350.

I've never done this with wort, but I do it all the time with pots of food that I need to cook for long periods of time. It beats having to keep stirring to keep the food from burning on the bottom of the pot.

Brilliant!  I never thought of that.

I would not want to try to lift a pot of 8 gallons of boiling wort out the oven and onto a stove top.  That's asking for a trip to the ER with scalds...

Good point, but a lid placed on the top will prevent splashing. Works with a fairly large pot off soup.

Its not just the splashing, its also the weight.  Each gallon weight 8lbs.  Moving 50+ lbs of boiling water anywhere is just an unnecessary risk IMHO.

While you may get to the boil in the oven, there's no guarantee it will stay boiling.  My stove top cant keep much more than 3 gallons at a boil.  Maybe with a high BTU burner on a gas stove you can achieve more, but if this is a rental apartment like the sound of it, I'd wager its the typical electrical stove top.  It's also going to take quite a while to boil water in the oven given the poor heat transfer of air.  I'd rather have a pot sitting on a burner than blowing 400F air on it.

There's nothing wrong with partial boils to keep it simple and faster (unless you're trying to do a pils). Just hop accordingly.
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: bo on December 08, 2011, 03:31:25 PM
Something you might try is to put the kettle in your oven, assuming it will fit. Get it to a boil and then place it on a burner to finish. The oven heats the entire pot, so you don't risk burning or caramelizing the wort during heatup. I would recommend putting a remote sensor in the wort so you know when it approaches boiling, so you can get it out of there before it boils over. I set my oven at 250F for food, because I'm not in a hurry. Not sure what to set it for with wort, but I would suggest starting around 300 -350.

I've never done this with wort, but I do it all the time with pots of food that I need to cook for long periods of time. It beats having to keep stirring to keep the food from burning on the bottom of the pot.

Brilliant!  I never thought of that.

I would not want to try to lift a pot of 8 gallons of boiling wort out the oven and onto a stove top.  That's asking for a trip to the ER with scalds...

Good point, but a lid placed on the top will prevent splashing. Works with a fairly large pot off soup.

Its not just the splashing, its also the weight.  Each gallon weight 8lbs.  Moving 50+ lbs of boiling water anywhere is just an unnecessary risk IMHO.

While you may get to the boil in the oven, there's no guarantee it will stay boiling.  My stove top cant keep much more than 3 gallons at a boil.  Maybe with a high BTU burner on a gas stove you can achieve more, but if this is a rental apartment like the sound of it, I'd wager its the typical electrical stove top.  It's also going to take quite a while to boil water in the oven given the poor heat transfer of air.  I'd rather have a pot sitting on a burner than blowing 400F air on it.

There's nothing wrong with partial boils to keep it simple and faster (unless you're trying to do a pils). Just hop accordingly.

Before I moved inside, I used to boil on the back porch and carry it into the house to chill. I needed to be close to the sink and I didn't feel the outside was a great environment for cooled wort. Not perfect, but it worked for years. Yes, you need to be very careful.

As for speed, I'm not sure what it would take. Keep in mind that the entire pot is surrounded by hot air, so you're not just heating the bottom. Of course the burner is very hot.

Just suggesting an alternate way to heat.
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: BP79 on December 08, 2011, 03:51:31 PM
I think the o-ring from the ball valve would melt if i tried the oven technique.  I'm also not the size of an NFL lineman, so there's no way I'm lifting a 50lb pot of hot liquid.
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: bo on December 08, 2011, 04:01:23 PM
The o-ring should be silicone, so that wouldn't melt. Now the ball in the ball valve might be another thing. I didn't realize it was more than just a pot.

Why don't you look into making a heatstick to supplement your range?
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: morticaixavier on December 08, 2011, 04:27:23 PM
I live on the 4th floor of an apartment complex in a rather urban area, so unfortunately I don't have the option of using a propane setup without doing something very stupid and/or illegal on the patio.  I'll do a test run tonight just to get a ballpark time of how long it'll take and to see if it's even possible.  That being said, the pot fits perfectly over two burners, so who knows.   

I don't think you will have a problem. I have done plenty of full boils on two burners of some pretty funky old electric and gas stoves. Maybe ended up a little darker than it might have otherwise but never tasted scorched. It might also take longer so there is the issue of continued conversion of the partial mash part. Until it reaches a temp sufficient to denature all the enzymes your wort will continue to convert and thus get slighly more fermentable. But not much I would think.
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: Jimmy K on December 08, 2011, 04:41:20 PM
It really depends on the stove and the heat output of the burners. My stove can easily boil 6.5 gallons of wort.  The pot will be loosing a lot of heat from the sides, so depending on how your setup is, you could put some insulation around the pot to help it boil.

Something like this
http://www.homebrewersassociation.org/forum/index.php?topic=9969.0
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: BP79 on December 09, 2011, 01:31:41 PM
So it took about 50 minutes, but with two burners I was able to get 6.5 gallons to a boil.  Thanks for that link, I ordered some reflectix overnight on Amazon, so hopefully that time can get reduced... no hardware store w/in 30 miles of Manhattan has it. Pathetic, I know.

Great call on the heat stick.  I asked my wife to get me a stir-plate for Christmas.  I can't imagine how she'll react when I ask her for one of those too.





Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: gymrat on December 09, 2011, 02:50:53 PM
Can someone describe how you do a partial boil? Do you only boil first runnings and top off with water in the fermenter? Or do you boil the first runnings and add the sparged runnings later?
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: a10t2 on December 09, 2011, 03:04:52 PM
Can someone describe how you do a partial boil? Do you only boil first runnings and top off with water in the fermenter? Or do you boil the first runnings and add the sparged runnings later?

It would depend on what you were brewing. If it was a big beer you'd probably only be able to use the first runnings. For a smaller beer you could probably fit in a sparge by doing a thick mash.

http://seanterrill.com/2011/01/16/of-ice-and-10p/
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: Jimmy K on December 09, 2011, 04:25:21 PM
Most homebrewers are doing extract/partial mash recipes when they talk about partial boil.  This makes it easier to just add less water to the kettle. You could boil just the first runnings of an all grain batch and top up later with water - it will hurt your efficiency though so you'd have to mash extra grain. I don't know anyone who does this.
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: euge on December 09, 2011, 06:21:59 PM
Most homebrewers are doing extract/partial mash recipes when they talk about partial boil.  This makes it easier to just add less water to the kettle. You could boil just the first runnings of an all grain batch and top up later with water - it will hurt your efficiency though so you'd have to mash extra grain. I don't know anyone who does this.

It's that awkward intermediate stage before people go AG. Like puberty. ;)

Useful technique if you have equipment/space issues- I actually built a 2 gallon tun to do this for AG test batches but could certainly do it's job for a partial boil.

I guess it (the term) could double for a late extract addition as well?
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: bo on December 09, 2011, 06:28:09 PM
Most homebrewers are doing extract/partial mash recipes when they talk about partial boil.  This makes it easier to just add less water to the kettle. You could boil just the first runnings of an all grain batch and top up later with water - it will hurt your efficiency though so you'd have to mash extra grain. I don't know anyone who does this.

It's that awkward intermediate stage before people go AG. Like puberty. ;)

Useful technique if you have equipment/space issues- I actually built a 2 gallon tun to do this for AG test batches but could certainly do it's job for a partial boil.

I guess it (the term) could double for a late extract addition as well?

Once I started growing hair around my fermenter, I decided it was time to move on to all grain. :D
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: a10t2 on December 09, 2011, 07:59:28 PM
I don't know anyone who does this.

I can only brew outside 7-8 months a year, so it's partial boils on the stove or nothing. For a 1.040 no-sparge beer the efficiency is about 70%, so it isn't like it absolutely kills you either.
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: Bret on December 10, 2011, 06:33:01 PM
It really depends on the stove and the heat output of the burners. My stove can easily boil 6.5 gallons of wort.  The pot will be loosing a lot of heat from the sides, so depending on how your setup is, you could put some insulation around the pot to help it boil.

Something like this
http://www.homebrewersassociation.org/forum/index.php?topic=9969.0

^me too.  My GE gas stove has a high output burner. It's not ideal, but works just fine.
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: madscientist on December 12, 2011, 01:48:04 PM
Most homebrewers are doing extract/partial mash recipes when they talk about partial boil.  This makes it easier to just add less water to the kettle. You could boil just the first runnings of an all grain batch and top up later with water - it will hurt your efficiency though so you'd have to mash extra grain. I don't know anyone who does this.

It's that awkward intermediate stage before people go AG. Like puberty. ;)

Useful technique if you have equipment/space issues- I actually built a 2 gallon tun to do this for AG test batches but could certainly do it's job for a partial boil.

I guess it (the term) could double for a late extract addition as well?


I have a 2.5gal mash tun that I use for partial mash batches.  I also do partial boils.  My mash volume + sparge volume gets me right around my 3 gallon boil volume. All the beers I have done this way come out great. I have everything calculated out in Beersmith though, so it makes it pretty easy. 

I can mash 2-3lbs of grain and suppliment the rest with DME.
Title: Re: Full boil on stove-top: pre-heat "top off" volume
Post by: krustybb on December 20, 2011, 03:12:45 AM
Yeah I do a full boil in an 8 gallon pot and have no problem. I do have a commercial gas stove with some serious output. I think the big pot is great.

Krusty

http://krustysbigbrews.blogspot.com/ (http://krustysbigbrews.blogspot.com/)