Why Boil The Extract?

[vanceonbeach]

I'm sure this will sound like the stupidest newbie question ever, but here goes. Why do you boil malt extract?

I only discovered there can be more to homebrewing than mixing a tin of goop with a bag of sugar a couple of weeks ago. Since then I've read every book in the public library on the subject and spent every spare moment on the interweb finding out all the amazing stuff you can do. Based on the amount of time, space and cash available I'll be upgrading to brews with extracts, hops and steeping some grains (and dreaming of a day a few years from now when the kids can entertain themselves for a couple of hours).

Now I think I understand that you steep the grains to get the goodness into the wort, and you boil the hops to add bitterness and aroma, all makes sense so far. But why do you boil the extract? Does it change the sugars and resulting flavour because as far as I've read all it does is change the colour? Am I missing something here? Most recipes give a 60+ min boil time, others say you can do a late addition but still boil for 10-15 mins minimum? Some websites seem to be particularly militant and say it's also essential to boil kits even though the manufacturers say not to because it can ruin the flavour.

So, steeping grains - check. Boiling hops - check. Boiling extract - totally confused!

 

[Adamt]

Lots of funky bacteria and other stuff lives in grain. Without access to sugars these things will sit dormant. When the starches are converted to sugars and are dissolved (or just the sugars are dissolved, in the case of crystal malts) in the liquor, they are much more accessible to the funky beasts. Without a boil, a fair amount of the population survives, gets chewing, and makes your beer taste funky.

 

[Bribie G]

brewing 101

You take malted barley and mash it with hot water at around 66 degrees for 90 minutes. In that time enzymes in the malt convert starches to sugars which you drain out into the kettle, with rinsing (sparging).

Boil for another 90 minutes to break out proteins etc and you end up with wort.

At the malt extract factories they do that process for you and the wort (in this case with no hop additions) is boiled under vacuum to reduce the wort to a syrup, in the same way that milk is turned into Nestles condensed milk etc.

So the malt extract has already had the crapper boiled out of it so there is no need to boil it further IMHO. An exception to this is that if you are getting the extract 'on tap' from a honey dispenser at a local home brew shop you could dilute it and bring to the boil for a few minutes to sanitize in case someone has dropped their false teeth in it at the shop.

Apart from that I regard malt extract as being biologically sound much the same as honey and use it 'as is'

:icon_cheers:

edit: Adam got in first here and I totally agree that there is a zoo living in grains but I would maintain that during the production of malt extract the prolonged boil at the factory would destroy any organisms. However when using specialty grains such as crystal malt the steepings should be thoroughly boiled to sterilize them. Never add steepings directly to the wort or you risk all sorts of nasties. (I take it that's the aspect that Adam was referring to)

 

[manticle]

I do it because it makes me look like I know what I'm doing and I can pretend I'm slightly closer to all grain brewing.

Also it smells good and hops in water just wouldn't be the same.

 

[Alby]

Good questions Vas..have been wondering much the same. I understand exactly how you feel about waiting for the kids to be of an age where they can entertain themselves. Im lucky if I get 5 min at a time without needing to change nappies or play trains!

Apologies for a slight detour on this thread but Im a bit confused about the term 'extract'...I had thought this was the goop in the 1.7kg can that I add dex or BE2 to? Doesnt sound like what you guys are talking about.

 

[jonocarroll]

Just in case you haven't got it figured yet - the tendency for a lot of questions is you will ask 5 brewers and get 6 different answers. This is just one of those contentious points - to boil or not to boil. Don't worry, it's by far not the stupidest noob question. Don't get these folk started on what is.

Anyhoo - the all-grain (get used to that term, it's what the last few chapters of all those books are about, and what people on here will talk about 'till the cows come home - needless to say, it's a damn fine way to make beer... I'm off track, blame St. Patrick) method of making beer involves boiling for 60-90 minutes. There are many advantages here - proper utilisation times for hops (bitterness, flavour, and aroma all need rather specific boiling times) is just one, so that's definitely the way to go for all-grain.

For anything faster (read: shortcuts), as Adamt said, boiling has the advantage that you definitely kill anything lurking in the kit (although, I agree with BribieG that it should be 'food safe' by then) but has the disadvantage that you'll probably boil off any aroma hop additions that are included with a kit. If it's an unhopped extract, that's no worry. The 'hot-break' should already have occurred at the factory, so that shouldn't be an issue.

I've heard arguments saying that there's a chemical reaction between hops and malt when boiling, but I have no references to back that up. In the end, it's up to you. I like the idea of a boil, but I've made beer with and without and never had a 'bad' batch. I know I never actually answered your question, but c'est la vie. Good luck with it, you're in for a heck of a ride. :icon_cheers:

 

[Adamt]

Just to tack onto the end of QB's post... if you're boiling hops to extract bitterness, or flavour, etc.; the mild acidity of the wort aids in extracting the compounds you want from the hops.

 

[jonocarroll]

Just to tack onto the end of QB's post... if you're boiling hops to extract bitterness, or flavour, etc.; the mild acidity of the wort aids in extracting the compounds you want from the hops.

Well, there you go. Cheers Adamt.

 

[loikar]

I know I never actually answered your question, but c'est la vie. Good luck with it, you're in for a heck of a ride. :icon_cheers:

HAHAHHAA!, GOLD!

 

[flattop]

Extract
LME= Liquid Malt Extract (like a can of goop but can be many varieties including for example a Coopers Kit)
DME= Dried Malt Extract which is LME that apparently is blown up in the air and dries in crystals

*Note cans of goop often have other additives, some have Hops for example....

I'm with Bribie on this one, i don't boil mine, however i do dissolve both in boiling water which is probably enough to kill the weaker bugs....
The stronger bugs get killed by my stomach acids after a month or more in the bottle

 

[vanceonbeach]

Wow this site is awesome, loads of really helpful responses

So I wasn't going crazy, this is one of those questions of style or preference rather than a hard and fast "if you don't boil your extract you'll end up with 23L of balsamic vinegar" type situation.

To get the mildly acidic wort I want for better hop boiling, is this for example the amount of LME or DME that ianh's excellent kit and extract spreadsheet recommends adding to the boil?

 

[chappo1970]

...I only discovered there can be more to homebrewing than mixing a tin of goop with a bag of sugar a couple of weeks ago...

Welcome Vas to dark art of brewing your own beer. Don't worry this is only the start of the obsession just wait to your talking to your wort. I does happen.
Really can't add more to what has already been said by the guys. But I can say your about to learn a hell of a lot if ya stick around.

Just in case you haven't got it figured yet - the tendency for a lot of questions is you will ask 5 brewers and get 6 different answers... Don't worry, it's by far not the stupidest noob question. Don't get these folk started on what is.
....

Never a truer word written QB...

Just don't ask the dreaded airlock question Vas and all will be fine and dandy.

 

[pdilley]

Its been a many a year since canned anything could be found on the shelf with the can puffed out from infection. The canning process kills off the bugs that spoil food so it stands to reason that canned extract is rather bug free.

 

[geoffd]

Boiling the extract is simply to pasteurise your brewing water, it will also drive off chlorine which is not good for yeast. It also gives the oportunity to add hops for bittering and flavour. Aroma oils from hops quickly evaporate at boiling point so either wait to add hops from aroma while the wort is cooling or better still dry hop (steeping hops in the cooled fermenting wort - preferably about 3 days or so from the end of fermentation so the aroma doesnt come out the air lock with all the Co2). Welcome to the all consuming passion of drinking brewing.

 

[QldKev]

I've just converted to the dark side (AG); but I used to be a kit boiler. My experience follows.

Now there's bringing a kit to the boil, and boiling a kit.

Bringing a kit to a boil: Bring your water up to a boil add LDME (Light Dried Malt Extract) and some hops, boil for 5 to 15mins, then add contents of can/kit, add some more aroma hops at flame out. In this process you have not converted a higher percentage of the hops into bittering.

Boiling a kit: Bring your water up to a boil, add LDME then the can/kit. Boiling the entire kit at this stage you will convert a lot of falvour hops into more bittering hops; you can boil for up to 60mins, but personally I would not go more than 40mins. So you are changing the profile of the kit. Since you have lost the flavouring hops, at 15mins prior to he end of boil add extra hops to replace the flavour hops you have bittered. At flame out you can add some aroma hops if required. By doing this you start with a more bitter base and allow yourself to customise the beer with different hops.

I haven't mentioned about ratios of LDME to hops etc here, as this varies to a specific beer style.

QldKev

 

[smollocks]

To get the mildly acidic wort I want for better hop boiling, is this for example the amount of LME or DME that ianh's excellent kit and extract spreadsheet recommends adding to the boil?

Yes, the consensus seems to be that you should have a specific gravity of 1040 in the solution that you are boiling with your hops. This is achieved with 100g DME per litre of water. LME uses a slightly different ratio that you could find by searching. The more you increase the gravity over 1040, the less efficiently you will utilise the hops. If you're using ianh's spreadsheet, I believe you are prompted for the correct amount of dry or liquid extract required to achieve the boil gravity of 1040.

This whole question of whether and why to boil extract used to confuse me too, but I've rationalised it to what I think are 2 options:

1. If you wish to use your own hops for bitterness, flavour & aroma, use an unhopped extract and boil a 1040 solution for an hour as you add the hops. Optionally add the remainder of the extract for the final 10 minutes if you wish to sanitise and/or help it to dissolve more easily.

2. If your extract already has hops, boiling will drive off the effect of the hops and is therefore not recommended (unless this is your objective). A short boil of your extract may be used to sanitise and/or help it to dissolve more easily, but again this is optional.

So the answer to boiling extract is "it depends". If you are controlling the hops of the beer, then you should boil. If you are happy with the hops provided in your kit, then anything more than a short sanitation boil is detrimental.

 

[MHB]

The important distinction between Kit and Extract brewing needs to be clearly understood.
Kit brewers rely on the kit to provide the bitterness; extract brewers are adding the bitterness themselves.

There is no need to boil kit brews; not saying there aren't advantages just that you don't have to. One big reason to boil a kit is that when the LME is made is that it only receives a minimum boil usually 10-15 minutes; this removes the bulk of the hot break material. The sweet water is then sent to the vacuum evaporator, producing concentrated extract (LME)
The bitterness is added later in the form of an extract (mostly Iso); other hops where they are used are also added in the form of extracts, any grain in the form of concentrated pasteurised tea.

Extract brewers are in effect reconstituting the sweet water that was originally made in the brewery. From then on all the same processes and procedures are followed as with an AG wort.

The one big difference being that it is easy to boil only a portion of the extract in water (to give a smaller wort of similar gravity to the full volume finished wort) with the hops and then add the balance of the extract late in the boil. It's important to get the gravity of your boil right or your hop utilisation will be all over the place.

Here is a helpful teaching article on wort boiling (from the IBD website) View attachment 25497

A couple of myths that need busting:-

You can't really boil the bitterness out of a kit; the half life of Iso Alpha Acid is in the order of 40 minutes in the kettle. That means that the end of a 2 hour boil of the alpha will still be there.

A kit isn't concentrated wort; if you tried to reduce finished wort you would get too many reactions, mainly between small protein fragments and organic acids. Some of these reactions are very similar to what happen in the formation of chill/permanent haze accelerated to the point were the results are like tar.


Extract brewing is a great step on the way to AG, you need all the skills and equipment you use as an extract brewer and you can make some fantastic beer.



MHB

 

[vanceonbeach]

OK thanks to all the helpful answers I think I know where I'm at on this question.

When I steep my grains I need to boil the resulting wort to kill all the funky bacteria [thanks Adamt]. I'll want to add some malt extract to that wort to bring the SG up to 1040 when I use it to boil my hops [thanks QB & Adamt]. But I don't need to boil the whole of my malt extract because it's sterile out of the can and they boiled the crap out of it during the manufacturing process [thanks flattop, BribieG & MHB].

Even better this is the answer I wanted to hear because I do have a 12L stock pot with enough head room to boil 7L or so of grain steeped, hoppy goodness but I really didn't want to splash out on something big enough to boil 19-23L (the wife might suggest if I have hours to stir expensive pots of boiling goop maybe I'd like to do a bit more of the cooking).

Cheers everyone

 

[chappo1970]

...(the wife might suggest if I have hours to stir expensive pots of boiling goop maybe I'd like to do a bit more of the cooking).

Cheers everyone

pssst! Vas! That's why you end up with a man cave to do your brewing in mate!

 

[manticle]

OK thanks to all the helpful answers I think I know where I'm at on this question.

When I steep my grains I need to boil the resulting wort to kill all the funky bacteria [thanks Adamt]. I'll want to add some malt extract to that wort to bring the SG up to 1040 when I use it to boil my hops [thanks QB & Adamt]. But I don't need to boil the whole of my malt extract because it's sterile out of the can and they boiled the crap out of it during the manufacturing process [thanks flattop, BribieG & MHB].

Even better this is the answer I wanted to hear because I do have a 12L stock pot with enough head room to boil 7L or so of grain steeped, hoppy goodness but I really didn't want to splash out on something big enough to boil 19-23L (the wife might suggest if I have hours to stir expensive pots of boiling goop maybe I'd like to do a bit more of the cooking).

Cheers everyone

I steep my grains then strain and rinse into a 10L stock pot, bring that to the boil and use that liquid to boil my LME in, adding hops along the way. The fermenter is topped up with cold water to drop the temp. If you're super worried about infection you can boil and cool 10 L of water first. I'm in Melbourne and I happily drink water from the tap every day so I don't bother.