Extract brewing - partial boil questions

[Matheos]

Hello guys,

I am rather new to the brewing scene and will do my third batch this weekend. Earlier batches have been 1x coopers lager prehopped LME (basic stuff) and last one was 19L own recipe DME extract recipe.
Last brew, I basically boiled my hops in plain water for 45min for "bittered hop tea" and then simply mixed my DME in cold water in the fermenter, then added the hop tea and topped off.

As I grow more experienced though, I strive to improve my process. This time, I have a 10L pot (large pots are extremely hard to come by here in Finland, especially ones that fit our induction stove). Last time I only had a 5L one. Because of the extra room, I am this time considering boiling some of the extract (mix it before the boil as it clumps easier when boiling), then bring it to a boil, add hops and boil for 60min and so on. Then maybe add the rest of the DME 15min from the end, or just straight in the FV. I am using 2.5KG of DME, no steeping grains nor LME.

My questions are now these:
- I have heard that boiling hops in just water is not the best, as the utilization suffers. Is this true or is it somewhat a myth, and to what extent?
- How much DME will I have to boil (in KG please), in order to get good utilization of my hop boil (considering above question is true)?
- If you guys suggest boiling DME is a good thing (either all or some), how much water would you suggest is sufficient per unit of DME? For example how much water for dissolving 1kg of DME? 50-50 ratio? This ratio may limit my ability to boil all DME, due to the size of my pot.
- I assume calculators (recipe), assume that the worth has fermentables in it when boiling hops? This affects the amount of hops needed to reach my IBU target, yes?

Excited to hear your opinions on the matter. I know a lot of these questions are debateable and subjective, but I am still to form my own opinion. Initial thoughts are that I would like to test boiling some of the DME this time, as last time I boiled none. Just to get experience and see the difference. Maybe 1KG DME in, pre-boil (bags are 500g each).

 

[BrewnWKopperKat]

My questions are now these:
- I have heard that boiling hops in just water is not the best, as the utilization suffers. Is this true or is it somewhat a myth, and to what extent?
- How much DME will I have to boil (in KG please), in order to get good utilization of my hop boil (considering above question is true)?
- If you guys suggest boiling DME is a good thing (either all or some), how much water would you suggest is sufficient per unit of DME? For example how much water for dissolving 1kg of DME? 50-50 ratio? This ratio may limit my ability to boil all DME, due to the size of my pot.
- I assume calculators (recipe), assume that the worth has fermentables in it when boiling hops? This affects the amount of hops needed to reach my IBU target, yes?

Assuming you want to continue with a full volume, 60 minute boil, have you seen this: Brewing better beer with Malt Extract ?

Basically, it's a full volume boil, but with a very low OG and most of the DME added at the end of the boil (for pasteurization). The article explains how to adjust the amount of bittering hops using some basic math (so no need for recipe software to adjust the recipe).

The idea isn't new: people will talk about doing something similar (for example, 25% of the DME at the start of the boil). The strength of the article is that it describes how to adjust hop amounts.

 

[Matheos]

Assuming you want to continue with a full volume, 60 minute boil, have you seen this: Brewing better beer with Malt Extract ?

Basically, it's a full volume boil, but with a very low OG and most of the DME added at the end of the boil (for pasteurization). The article explains how to adjust the amount of bittering hops using some basic math (so no need for recipe software to adjust the recipe).

The idea isn't new: people will talk about doing something similar (for example, 25% of the DME at the start of the boil). The strength of the article is that it describes how to adjust hop amounts.

I will have a look. Thanks! Though, by "full volume" I am not sure what you mean. My largest pot is 10L which is not enough for the whole batch, so I would either way have to top off with cold water in the FV (at least for batches greater than like 9L)

EDIT: Had a look but cannot find the part about how to adjust the bittering hops?

 

[BrewnWKopperKat]

Had a look but cannot find the part about how to adjust the bittering hops?

It's in the paragraph after step 10.

 

[BrewnWKopperKat]

full volume

All the water (+ water to account for boil off) at the start of the boil.

 

[Matheos]

It's in the paragraph after step 10.

Ah that's what you meant. I thought there would be some more complex calculation

All the water (+ water to account for boil off) at the start of the boil.

Ah, well I can't do that. As I mentioned. So how would you suggest I adapt it to a partial boil? Add about 150g DME at pre-boil, do regular boil for bitterness and then mix the rest in with top of water in FV? Or maybe mixing it at flameout all to a very concentrated 8-9L worth.

 

[KeizerBrewr]

I agree with @BrewnWKopperKat has stated above. I still do extract batches. I despise LME with every fiber of my being(almost impossible to keep from scorching, no matter how slow I add it and stir, DME IMO is way easier to handle and use. I do 6 gallon boils(accounting for boil off and equipment loss for my set up) and I only add a half kilo to a kilo of my DME at the start of the boil to get proper utilization and then I add the remainder of my DME the last five minutes of the boil to help keep the wort from darkening. It's arguable that DME shouldn't need a boil given it has been properly stored, which is why the last few minutes would be sufficient to kill any nasties that probably aren't lurking in it. So for your 10L kettle a 500g bag during your boil would be sufficient. Most extract recipes are designed around a partial volume boil, so don't adjust the hop schedule. Just add 500g of DME to your kettle of water, bring to a boil and follow the hop schedule per your recipe and then add the remainder of the DME the last few minutes. Then adjust your final volume in your fermenter with more water. If you are able to find one, knowing it's hard to find large kettles in your neck of the woods, makes doing full volume boils easier. Just requires a chiller to get your wort to pitching temp as you lose the ability to add cold water to your fermenter like you did when you did partial boils.

 

[Birrofilo]

The answer depends to what you want your batch size to be.

Personally I wouldn't bother with a batch size of less than 15 litres.

A simple way to adopt a recipe for your setup would be to scale a recipe for 15 litres.

You should use an anti-foam during boiling so as not to have the very nasty event of an overboil (if that happens, stop doing anything and clean all the sticky stuff immediately before cleaning it becomes a nightmare).

Reach the density that your recipe calls for during hop extraction.

E.g. say that you want to make 15 litres of final product, put 8 litres in your kettle and as much DME as to reach the density which is called by your recipe.

Boil your wort with the amount of hop which is called for the entire 15 litres. You don't need to boil hop pellets more than 30 minutes. (You could also use twice the hop and boil for only 8 minutes).

Then after the boiling you top up with additional water and additional DME and you pitch yeast.

If you give us more detailed goald (what style, what volume) we can give more detailed examples.

 

[BrewnWKopperKat]

[...] So how would you suggest I adapt it to a partial boil?

Half the DME/water at the start of the boil, the rest of the DME at flame-out, top-off with chilled water.

How To Brew, 4e is a good source for the details (as well as pieces of information that don't often appear in forums).

 

[Matheos]

@KeizerBrewr @Birrofilo @BrewnWKopperKat Thanks guys for all the great advice. The recipe in question is a home made experiment so we made it ourselves.
Target in FV: 19L
Pre-boil: 9L
Boiloff maybe 1L
2.5KG Extra Light DME
24g 5,5AA Cascade @ 60min
add grated ginger @ 15min (amount on brewtarget but in bed atm so cannot check lol)
(No aroma hops)
US-05 yeast

That is basically it. The IBU should be 17-20 something according to brew target, though I assume now that assumes dissolved dme in the boil, so will have to maybe then boil like 1KG of DME from the start of the boil as you said.

Is this common knowledge that pellets don't need to be boiled longer than 30min? Never heard before, but I am very inexperienced too. I will have to check what the calculator says tomorrow if I change hop addition to 30.

Unfortunately I don't have any anti foam pills. So we will have to try to be careful and pull it off the heat if it starts foaming up. My understanding is thar once it has passed that crucial point, it will calm down a bit? In terms of boilover?

As to adding the last to the boil at 5, if ir is purely for pasteurization, I am not sure it is worth the hassle and risk of boilover. We are using muntons prepackaged 500g DME bags, so I am quite confident the DME should not be contaminated in any way. Last time I used muntons, I boiled none of it, adding all 2.5kg to fv.

 

[Birrofilo]

30' boil of pellets equal more or less 60' boil with cones*.

Antifoam will be crucial for peace of mind. If you like Russian roulette, you can do without. 9 litres cold will grow in volume, when boiling hot, to 9,36 (assuming 4% volume expansion). Not much margin. A good antifoam will allow you to cook that beer, without antifoam I think it will be a bit of a stress. You can reduce the volume and compensate with more water later.

Let's assume 9 litres in the kettle including the 1,2 kg or so DME, with gentle boiling (without cover) and constant watch.
You should end up with more than 8 litres if you don't boil furiously, and with a density which is between 40 and 50 points, which is normal.
You boil the entire quantity of pellets in the kettle.

You then put the wort in your fermenter and you add the water and DME which you need to arrive to your final density (all the DME which you did not use in the kettle, and water enough to arrive to your volume). Don't use tap water because that will bring chlorine which is not good. Use bottled water from new bottles for toppling up. Considering that half of the water is not boiled, you might avoid aerating the wort.

*Hop extraction according to Strong:
cones 60': 23,1%
pellets 30': 21,9%
pellets 10': 10,4%

That means that if you multiply your cones hop weight by 2,2 and you use pellets you will extract the same "bitterness" in 10 minutes instead of boiling for 1 hour, which can be interesting if you fear browning of your beer. If you don't mind the browning, the long boil will impart a certain caramel-melanoidin-biscuit undertone (caramelization and Maillard reaction) which you could like.

I don't know what "style" is your beer so I don't know how important is clarity and how important is the effect of long boiling of DME on taste. Some people don't like it and will say it tastes of "extract beer".

 

[BrewnWKopperKat]

Thanks guys for all the great advice.

You're welcome.

 

[Matheos]

30' boil of pellets equal more or less 60' boil with cones*.

Antifoam will be crucial for peace of mind. If you like Russian roulette, you can do without. 9 litres cold will grow in volume, when boiling hot, to 9,36 (assuming 4% volume expansion). Not much margin. A good antifoam will allow you to cook that beer, without antifoam I think it will be a bit of a stress. You can reduce the volume and compensate with more water later.

Let's assume 9 litres in the kettle including the 1,2 kg or so DME, with gentle boiling (without cover) and constant watch.
You should end up with more than 8 litres if you don't boil furiously, and with a density which is between 40 and 50 points, which is normal.
You boil the entire quantity of pellets in the kettle.

You then put the wort in your fermenter and you add the water and DME which you need to arrive to your final density (all the DME which you did not use in the kettle, and water enough to arrive to your volume). Don't use tap water because that will bring chlorine which is not good. Use bottled water from new bottles for toppling up. Considering that half of the water is not boiled, you might avoid aerating the wort.

*Hop extraction according to Strong:
cones 60': 23,1%
pellets 30': 21,9%
pellets 10': 10,4%

That means that if you multiply your cones hop weight by 2,2 and you use pellets you will extract the same "bitterness" in 10 minutes instead of boiling for 1 hour, which can be interesting if you fear browning of your beer. If you don't mind the browning, the long boil will impart a certain caramel-melanoidin-biscuit undertone (caramelization and Maillard reaction) which you could like.

I don't know what "style" is your beer so I don't know how important is clarity and how important is the effect of long boiling of DME on taste. Some people don't like it and will say it tastes of "extract beer".

Visited the brewing store yesterday, so should have got those anti-foams then. Not even sure what they might be called in Finnish...
As the recipe is mine, and I live in Finland where we can't really grow hops, we almost exclusively use pellets here. So the recipe is made for pellet usage. I will play around with the boiltime though, as it would be nice to avoid as much caramelization as possible.

Regarding the pre-boil gravity, I have never measured this, would I simply mix the DME in the kettle and take a reading using my hydrometer? and then add until I achieve my pre-boil gravity? I assume this sample can safely be put back, as it will be boiled either way.

Regarding the tap water, I have a whole other thread about my water and it's contents and stuff. We used tap water last time and it was fine. I did however yesterday pick up campden powder to try to fight the chlorine. It is not bad, does not smell or taste (the chlroine), but would be nice to get out of there. Not sure if we can use the powder tomorrow though, as I don't yet have a scale with enough precision to measure that small amounts. Though, maybe we could pick up bottled water for the topping up, It's not too expensive, but it is a hassle

EDIT: Maybe we should lower the boil amount to 8L to try to counter boilovers as much as possible
EDIT2: Added beerxml file if anyone is interested. Can be imported to brewtarget. Tried playing with the boil time, but I won't reach my IBU target with 30min for the same amount of pellet hops according to the calculator. 60min is what makes me reach the target

 

[Birrofilo]

Pre-boil gravity can be calculated. A certain amount of DME dissolved in a certain amount of water will give you a certain amount of density.

Search in the forum for "total density" and you will find the way to compute it, it's easy.

 

[KeizerBrewr]

I wouldn't make this a big calculation-heavy brew. Brewing should be enjoyable and simple. Just add part of your extract pre-boil, run your hops, add the rest and be done. That's what I do now and my beers turn out great. RDWHAHB

 

[Matheos]

Pre-boil gravity can be calculated. A certain amount of DME dissolved in a certain amount of water will give you a certain amount of density.

Search in the forum for "total density" and you will find the way to compute it, it's easy.

I wouldn't make this a big calculation-heavy brew. Brewing should be enjoyable and simple. Just add part of your extract pre-boil, run your hops, add the rest and be done. That's what I do now and my beers turn out great. RDWHAHB

Interesting thing about the calculation. Will maybe check it out, but I also agree with Keizer that I don't think it's perhaps necessary to make it too much about the numbers. Tomorrow is brew day so we will see how it goes

 

[Birrofilo]

Mathematics is easy for the mathematically inclined (not my case), or for those who are not really mathematically challenged (that's my case)

Do you want what, 10 litres at 40 points: you want 400 points of density.
A kg DME has 367 points.

With 1 kg in 10 litres total volume you get 1,0367.
If you want 1,040 you must dissolve 400/367 = 1,09 kg or 1090 grams.

Playing with the hydrometer is much more work IMHO.

Good theory makes homebrewing simple.

 

[D.B.Moody]

Then maybe add the rest of the DME 15min from the end, or just straight in the FV.

I've been brewing with partial boils for over 25 years. My next brew I'm trying adding DME disolved in cold warter after the boil to the fermenter. I am not a fan of adding DME to hot wort as it creates a cloud of sticky dust that wants to settle all over the kitchen. When doing partial boils, you have to watch the pot, especially when hops are added. Be ready to move it off the heat source to calm down.

 

[IslandLizard]

Half the DME/water at the start of the boil, the rest of the DME at flame-out, top-off with chilled water.

Or use even less than half the DME at the start of the boil.
The lower the boil gravity, the faster you create bitterness from the hops, so you could boil shorter for the same IBUs, and the less you caramelize the wort.
The add the remainder of the DME directly after flameout. It dissolved much easier/better in hot than in cold wort.

How To Brew, 4e is a good source for the details (as well as pieces of information that don't often appear in forums).

That! ^

 

[Matheos]

Going to check out the book!

Yet to decide when adding the last part of the DME, might try to add to the hot wort, if for no other reason, to get experience as I did it in cold wort last time.

I am planning an 8L boil today to try to stay as safe as possible from boil overs. I know I have to monitor it closely either way, but I don't want to make my life harder than it already is xD

Using a DME calculator for a starter: DME Calculator | MoreBeer I calculated that for 8L I would need 913g of DME to reach around 1040 pre-boil SG. Brew target almost agrees, calculating the Boil SG at 1042. Perhaps brew target knows some specifics of my DME that the calculator does not?
I hope I got this correctly, though I am yet to find any detailed calculations for this, other than @Birrofilo's own post How to increase Abv %. What is the source of DME typically having 1.0367 for 1kg in 10L? Is there a way to get a more accurate measure, for my specific kind of DME?

I am probably complicating things as always. and should probably be fine just putting 1kg, but I think maybe I wil try to measure around 910g of DME instead to add before the boil today.

Oh yes, today is brew day Also side note: Got bottled water for the whole brew this time. I have campden powder bought but no scale good enough to measure the small amounts

 

[BrewnWKopperKat]

What is the source of DME typically having 1.0367 for 1kg in 10L? Is there a way to get a more accurate measure, for my specific kind of DME?

Chapter 4 (starting at about p 51) of How to Brew 4e walks through the math (in both lb/gal and kg/liters)

Perhaps brew target knows some specifics of my DME that the calculator does not?

Recipe software is a tool for estimating. Different apps will have slightly different models for estimating and may have slightly different source data.

Yet to decide when adding the last part of the DME, might try to add to the hot wort, if for no other reason, to get experience as I did it in cold wort last time.

With regard to adding ingredients "cold side" be sure you understand which ingredients are safe to add after the wort has been chilled and understand which ingredients must be boiled / pasteurized.

 

[Matheos]

Chapter 4 (starting at about p 51) of How to Brew 4e walks through the math (in both lb/gal and kg/liters)


Recipe software is a tool for estimating. Different apps will have slightly different models for estimating and may have slightly different source data.


With regard to adding ingredients "cold side" be sure you understand which ingredients are safe to add after the wort has been chilled and understand which ingredients must be boiled / pasteurized.

Yea I had time to check the chapter before the brew (Y).

And yea I think I have a pretty good idea of what ingredients can be added cold. Speaking of, we did add the remaining DME after flameout now, though as steam still was rising it was a bit of a hassle as it got sticky already in the bag at times... But we got it there Now fermenting

 

[BrewnWKopperKat]

as steam still was rising it was a bit of a hassle as it got sticky already in the bag at times

Ingredient producer (or supplier) web sites are often a good source of information on good practices:

[...]
4. DME—To keep Briess CBW® dry malt extract (DME) from clumping, dissolve it in hot but not boiling water (100-120°F) to make a slurry, then add the slurry to your boil.
[...]

https://www.brewingwithbriess.com/homebrewing/extract-brewing-basics/

So, rather than adding a dry product over a steamy liquid, make a slurry in a second dish, then add the slurry to the kettle.

 

[Matheos]

Ingredient producer (or supplier) web sites are often a good source of information on good practices:



https://www.brewingwithbriess.com/homebrewing/extract-brewing-basics/

So, rather than adding a dry product over a steamy liquid, make a slurry in a second dish, then add the slurry to the kettle.

Yup. This is exactly what we realised we should have done, but then it was too late haha. Oh well. We know until next time now. I suppose this slurry does not need to contain a lot of liquid, as in our case that would be a problem because we don't have much extra room. But yea obviously only enough to hydrate it a bit. Next time we are definately adapting this!

The brand was muntons, and from what I have found, they give very little info away, but I am confident the suggestion above would work well (Y)

 

[Birrofilo]

What is the source of DME typically having 1.0367 for 1kg in 10L? Is there a way to get a more accurate measure, for my specific kind of DME?

The potential varies but it is something like 1,035 or a bit higher than that. Sugar is 1,038 circa, or a bit lower than that, and DME is always some percentage points below sugar. 1,0355 is probably more representative of the average DME, because normally DME is 42 ppg, and 1,0367 equals 44 ppg.

Yes you can measure the exact potential of your DME if you need that precision.

You can, by way of example, weight 20 grams of your DME.
Then you put them in a graduated container and top it with warm water up to 200ml. You wait for it to dissolve.
You stir and pour the syrup in your cylinder and take a density measure with your hydrometer.

Let's say that your density will your density is 1,035.
That means that the potential of your DME is such that a kg of it, in 10 litres water, gives you a syrup with a density of 1,035 (because 20g in 200ml is like 1 kg in 10 litres).

This means that a kg of your DME has 35*10 = 350 total points.
This potential, giving a density of 1,035, of 1 kg in 10 litres can be divided by 0,8345 to arrive to the potential expressed in pound per gallon (ppg): 35 / 0,8345 = 41,94.

You can then insert the exact value in your program or spreadsheet (a note of caution: some programs use ppg, some others use a metric unit, e.g. 1 kg in 1 liter, and you also have the case where the documentation doesn't specify what it uses. This is a source of problems in the use of programs for what I read around. Insert the value in the exact unit of measure).

The variation between the various maltsters will be 1 density point or so, but if you brew with all extract, knowing the exact potential of your DME will make your calculation more precise and your results more predictable.

I usually don't care about this level of precision because being precise with water quantities is more difficult than it seems. So being in the ballpark is fine, and then the hydrometer will give me what I have exactly. In my mind, a typical batch is 23 litres, and 100g of a typical dry thing (be it sugar or DME) adds circa 36 points in 1 litre, which means: 60 grams add 1 density point to 23 litres approximately. This is useful for rapid "field" calculation and adjustment without having to go the computer.

Sugar also varies: some sources say 36 points per kg per 10 litres, others say 38 points, or 38,3, because sugars were all not made equals, like DMEs.