Boil Size

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Virginia_Ranger

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So I have heard that full boils produce a better flavor for extract brews so I would like to give it a shot. As of right now for extract brews I am simply boiling half and topping with cold water (saves an a** ton of time). I typically do 4 gallon batches and ferment in corny kegs. Can I do a 4 gallon boil in my 5 gallon pot? This would be on a gas stove burner. Thanks!
 

LostHopper

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Sounds dangerous (messy). 4 gallons of water+extract+4% boil volume expansion sounds over the top and on the the stove to me.

It might be worth boiling a 3 gallon batch and topping up 1 gallon.

I don't boil extract batches over 10 minutes and have done some where I heated just to boiling then stopped.
 

tsholl

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I agree, I've had some brews with 3 gallons of water + extract that have almost boiled over in my 5 gallon pot if I'm not paying attention. When I'm paying attention it's never a problem but that's with 3 gallons. I think 4 gallons would be too much.
 

IslandLizard

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So I have heard that full boils produce a better flavor for extract brews
Where did you hear that?
Generally that's not true. Especially when you split your extract additions, adding half at the beginning of the boil and the remainder at flameout.
In some cases, such as with very hoppy beers (e.g., IPAs, NEIPAs), a full boil may have some benefits, although there are ways to improve partial boils for those too.

I would allow for at least 2 inches of headspace in the kettle to prevent huge boilovers. You may still get some splashing, though.
Using a few drops of Fermcap-S will reduce foaming. You don't need a rocking rolling boil, a good simmer (surface rippling) is plenty.

Also keep in mind that your stove can only boil so much volume. By going much larger it takes longer to attain a boil, if ever, without using insulation and other tricks.
 

NGD

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So I have heard that full boils produce a better flavor for extract brews so I would like to give it a shot. As of right now for extract brews I am simply boiling half and topping with cold water (saves an a** ton of time). I typically do 4 gallon batches and ferment in corny kegs. Can I do a 4 gallon boil in my 5 gallon pot? This would be on a gas stove burner. Thanks!
I havent heard about full volume producing better flavor. Lighter color definitely. If you have any resources I could read up on please post them or shoot me a DM.
I‘ve done my last 4 brews with 3.5-4 gallon boils in a 5 gallon pot. You can do it, but I’m not sure if its worth the risk.

If you decide to do it here are my suggestions.

1. Do a really low boil...like a simmer. Theres zero need for a roiling boil as far as I know.

2. When you add hops, either turn the heat off or turn it way down.

3. When you start to get foam from the boil, scoop it off. No idea if this makes a difference but it seems to work.

4. Don’t walk away..second you do you’ll have a boilover.

5. If your doing a big beer with a lot of extract and hops...save half of the extract for flameout and stir the hell out of it. I typically do that for all my extract batches anyway. It is especially important for large malt bills. It adds a fair amount of volume.

Sure I’m forgetting something but thats what has worked for me.
 
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Virginia_Ranger

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Somewhat related question, how much DME do partial mash grains need? Preferably I like to add most of the DME right at flame out but I remember seeing somewhere partial mash grains need some DME to bind / extract properly.
 

IslandLizard

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Somewhat related question, how much DME do partial mash grains need? Preferably I like to add most of the DME right at flame out but I remember seeing somewhere partial mash grains need some DME to bind / extract properly.
I think I've read somewhere (How to Brew maybe) that having some gravity in the boil is beneficial, perhaps for hop extraction/bittering or other flavor development, kettle reactions, 'binding,' etc. Not sure if this is actually true though, but in early days I made some hop teas with plain water and they did not come out well. Not sure if there's a low gravity limit or what that is.

Unless it's a really small mini (partial) mash you'd probably have plenty of gravity in the wort, especially with reduced volume or partial boils. Now hop utilization, the isomerization of alpha acids (the bittering reactions), reduces with rising gravity. With partial boils, especially the more concentrated ones, that could start playing a role, so be aware of that.

Except for wanting extra kettle reactions (e.g., Scotch Ales, Barleywines), during partial boils I would try to keep the gravity and volume the same during the boil. IOW, add boiling or near boiling water as you boil off. If you're on a stove it's easy to keep a small pot on a very low simmer on the side for top ups during the boil.
 

BrewnWKopperKat

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Chapter 1 of How to Brew, 4e offers a well thought-out process for stove top brewing (half the water and DME at start, rest at end of boil). Chapters 2 through 8 cover various topics in detail (including using brewing salts with DME/LME).

If you are going to brew for a while, this book is worth your time.

Somewhat related question, how much DME do partial mash grains need? Preferably I like to add most of the DME right at flame out but I remember seeing somewhere partial mash grains need some DME to bind / extract properly.
With extract+steep, some people taste tannins in the beer. This is often attributed to "improper steeping". There are a number of suggested approaches to preventing this, including adding a small amount of DME to the kettle during the steep (the approach that "How To Brew" takes).
 

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With extract+steep, some people taste tannins in the beer. This is often attributed to "improper steeping". There are a number of suggested approaches to preventing this, including adding a small amount of DME to the kettle during the steep (the approach that "How To Brew" takes).
Often because instructions indicate to steep the (mere 1-2 pounds) of grains in the 3-4 gallons of brewing water. When the water has high alkalinity the pH will remain too high, which promotes tannin extraction. Nothing wrong steeping in 2-4 quarts of water instead and do a quick sparge. And/or add a few drops of lactic or phosphoric acid to the steeping water.
 

BrewnWKopperKat

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Often because instructions indicate to steep the (mere 1-2 pounds) of grains in the 3-4 gallons of brewing water.
Kit instructions get us started, forum discussions and well curated resources (books, magazines, ...) move us forward.

When the water has high alkalinity the pH will remain too high, which promotes tannin extraction. Nothing wrong steeping in 2-4 quarts of water instead and do a quick sparge. And/or add a few drops of lactic or phosphoric acid to the steeping water.
Good advice.

Chris Colby's Methods of Modern Homebrewing has a couple of additional variations on steeping that can be useful.
 

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They're all based on the notion of better hop extraction/utilization and less wort darkening due to reduced gravity when doing full volume boils.
As I mentioned before, a partial boil only using half (or less) of the extract in the boil (aim for around 1.030-1.040) can get you similar results for most beers. Not many extract brewers can boil that 6 gallons on their system (often a kitchen stove). Then there is the chilling issue.
For example, from The Maltose Falcons:
Well, you are not getting the best utilization of the hops this way, plus you end up darkening and at times over cooking the wort because of they concentration of sugars in the water. This is more true in the higher gravity beers. Going full volume boil, in a 7-10 gallon pot out on a propane burner will give you a better and more consistent product, without the excessive darkening and kettle caramelization normally associated with extract beers.
The HBT link mentions full boils prevent 'extract twang.' Would that be related to reduced caramelization/darkening? I thought the cause of 'extract twang' is not known.
 

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I'll add that there is believed to be a limit of around 100 IBUs in maximum solubility (subject to debate). So if you partial boil at half volume and add equal volume for top-off, you can only get about 50 IBUs in the final wort. That may or may not bother you.
 

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I'll add that there is believed to be a limit of around 100 IBUs in maximum solubility (subject to debate). So if you partial boil at half volume and add equal volume for top-off, you can only get about 50 IBUs in the final wort. That may or may not bother you.
That's certainly a limitation. General dissolvability of hop oils is related to that too, so hop drenched IPAs and NEIPAs need a revised process as do more bitter beers, over 50 IBU.
In some cases, such as with very hoppy beers (e.g., IPAs, NEIPAs), a full boil may have some benefits, although there are ways to improve partial boils for those too.
Brewing twice a half batch (without topping up) is probably the easiest way around those limitations.

In that scenario, using malt extract a boil is not absolutely needed, except to attain bitterness (IBUs). A partial extract brewer could use a somewhat larger bittering charge or a little more hop oil extract to cut down on boil time. Late hop additions and/or a whirlpool/hopstand at lower temps provide the intended lupulin load. Having a chiller would be handy.

Keep a simmering pot with water on the side to top up the boil kettle perpetually to counteract evaporation and resulting wort concentration during the boil.
 

Smellyglove

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Nobody has mentioned maillard reactions? If you have more sugar in the kettle from the start, the more maillard you will get, and less "watery" mouthfeel.
 

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