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Extract Kit - Full Boil vs. Partial Boil

So, I have a 7.5 gallon kettle and I’m considering doing a full boil for my next brew (sticking with extract for now).

Do I need to alter partial boil extract recipes/instructions in any way (other than boiling 5 gallons instead of 2.5)? Will I likely need to move from the stove to a propane burner? And, is it possible to cool 5 gallons quickly enough in a sink or tub full of ice water, or should I couple this change with a new wort chiller?


Hop utilization will increase with a decrease in wort gravity - you could adjust by using slightly less hops in the boil (or ignore). You will probably need to use propane to boil unless you have an awesome stove. And you can chill the whole kettle, but this is a perfect excuse to buy a new IC (and you will wish you had if you don’t).

If you can do a full boil, do it.

When I do a full boil following a kit I steep my specialty grains in 2-3 gallons till i reach 165, then I add a quarter to a third (eye-balling it) of the malt extract at the beginning of the 60 minute boil, and the final parts at the last 10 minutes. This will make your wort more hoppy, so adjust your hop additions accordingly if you care about this.

The 7.5 gallon pot I use is huge and fits over two of my burners, so I use it on the stove top and it boils 5.5 gallons no problem. You will have to see if your stovetop can handle all that liquid and if a burner is a better option.

I would encourage you to get a chiller. Setting it in ice water is going to take a while. I stir my wort continuously with a wort chiller and it takes about twenty minute to get to 62F.

you know what, this weekend we did all our boils at 5gal with extract kits (started with 6gal) and that was a suggestion by a fellow member whos been brewing for a few years now so i wouldnt know the difference just did what he said and will know in about 4-6 weeks … everything is moving along fine in the fermentation dept !!
Sorry that was prob no help … other than “he said so” :slight_smile:

Great stuff, thanks!

I can kinda sorta fit the kettle over two burners, but it leaves flames exposed, which makes me a little nervous. I have a propane burner on my grill, so I’ll see if it can handle the weight/size of the kettle and use that if it can.

What’s the benefit of splitting the extract like that? Do you do that with all malts in the recipe (e.g., 1/3 of DME, 1/3 of LME up front, then the rest of both during last 10 minutes)? And, finally, if you have a 10 minute hop addition, do you adjust that to account for the late malt addition(s)?

Would “slightly less” entail 3/4 as much? Or, just a few pellets?

Finally, does a decrease in wort gravity result in lower ABV?

The difference in hops would be about 10%, its really not going to that noticeable. The late additions are even less affected, so no need to adjust those. If I was going to pull a few grams from my bittering charge at 60min, I’d throw them in at 5min.

Yes a decrease in gravity means lower ABV.

Yeah you can split both LME and DME that way. It helps with maintaining a truer color because there is less caramelization occuring. That malt has already been cooked considerably in the extract process, and while you can make great beer by adding it all at the beginning, I do think and others agree, that splitting the extract helps get rid of the so called extract “twang”.

About your flames going over the sides, just turn them down a bit, your still getting a lot of heat on the bottom of that kettle. I have my pot sitting more over the front on a bigger flame and then I turn the rear flame down so it is focused on the bottom, works well.

When you make it a full boil, is it better to add what you lose in evaporation at the end or add more at the beginning?

Yeah, that’s a good question. Is it better to start with ~5.5 gallons and boil down to 5? Or, is it better to start with 5 and compensate later for anything lost during the boil, so as not to produce a watered-down wort?

Until you’ve figured out your boil-off, you’ll probably want to plan on topping off afterwards. That’s the luxury of extract. All the sugar is condensed so you just need to dilute it. Start off boiling 5 gallons and measure how much you lose during the 60 minute boil. Your next batch, add the difference to the kettle and you’ll come out with 5 gallons after the 60 minutes.

Cool, thanks. I think I’ll go full brew + immersion chiller for my next brew day (weekend after this one).

Good luck!

I’ve yet to full boils but I may try it tonight since I just demo’d my enormous hood above my electric range. With that eyesore installed, there was only a few inches of clearance above the pot.

Thanks, good luck to you, too! Hope it goes well for you tonight.

Luckily my super smart girlfriend thinks (not drinks) prior to brewing. I was about to boil 6 gallons and she brought up that adding the extract would add volume which would probably have made us overshoot the 5 gallons post-boil. We boiled 5 gallons, added 3.15lb syrup, 1lb DME, and 1lb corn sugar. Post boil we needed to add more than a half gallon to reach the 5. If it was a different recipe with say 12lbs of malt syrup, I’m sure we’d be kicking ourselves for boiling too much water.

Remember to account for the additional volume the ingredients add!


Wow, nice save by your lovely lady, and thanks for the tip! :cheers:

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