Stella SMASH Clone Water Calculation Check

[Tetsuo1981]

Hi all.

I'm looking at making a Stella clone (here's the thread with the recipe Stella SMASH Clone Recipe Check )

Think I'm happy with it but the water calculations are a bit of a mystery to me. I've used the following video to try and figure it out


This is what I've got for 12.5 ltr batch size:

Strike water: 10.75ltr
Grain absorbtion: -2.5ltr
First runnings: 8.25ltr
Sparge: +8.25ltr
Pre boil vol: 16.5ltr
Evaporation: 3ltr (approx)
Post boil vol: 13.5ltr
Kettle loss: 0ltr (unknown, need to check and recalculate)
Fermenter vol: 13.5ltr
Trub loss: 1ltr (approx, over estimate)
Batch size: 12.5ltr

The evaporation, kettle loss and Trub loss are all approx as this is my first BIAB / all grain brew. The kettle loss I'm going to change by seeing how much my water kettle takes before hitting the tap (it has a false bottom).

Does this look correct? I think on my recipe thread I confused "batch size" with "strike water".

All feedback and criticism welcome, maths is not my strong point but I've got to start somewhere.

Thanks

 

[The-Engineer-That-Brews]

I think you've got a bit too much strike water there: you should be aiming for 2.3 - 3.0 litres of strike water per kilo of grain.
More detailed answer to follow...

 

[The-Engineer-That-Brews]

First of all, I'd say that water volumes can end up being somewhat specific to one's own kit and technique. However, within reason, if you wind up under/over volume then you can either carry on boiling a bit longer, or top up with a bit of (boiled/bottled) water.

In case it helps here are a few pointers based on my experience:

• typically it's easiest to start from the volume you want to end up with going into the FV ('batch size') and work backwards to the desired pre-boil volume (i.e. the amount you want to get out of the mash)
• remember that the volume of your beer will shrink by about 4% as it cools down, so don't be surprised if it looks like you've "lost some" compared to what initially came out of the kettle
• the amount that evaporates during the boil is hard to estimate, because it depends on how vigorously you boil and the surface area of your kettle
• I personally don't have any kettle loss, because I tip it all into the fermenter (obviously once I've filtered all the hop debris out)
• I always find I lose a surprising amount to the gunk at the bottom of the fermenter: you might find 1 litre a bit of a conservative estimate

OK so all that said, 16.5 litres looks about right for your pre-boil volume (although 3 litres is quite a lot of boil-off).

• you therefore want to get 16.5 litres out of the mash
• starting from your grain weight of 2.5 kg, you want to mash with about 2.3 - 3.0 litres of water per kilo of grain (so in your case, 5.75 to 7.5 litres of water). People will be queueing up to say you can go higher than that with impunity, but personally I wouldn't advise it.
• let's say you go with 3.0 litres per kilo: 7.5 litres of strike
• each kilo of grain will absorb something like 1 litre of water per kilo during the mash; so your first runnings will be something like 5 litres. You might get a bit more by squeezing the bag, but it could get a bit cloudy so don't overdo it.
• In that case, to hit 16.5 litres into the kettle you'd have to sparge with 11.5 litres.... which to me sounds like quite a lot of sparge for 2.5 kg of grain and you'd have to be very careful to avoid the gravity of the final runnings dropping below 1.010 sg.

If I were you, I'd stick with 7.5 litres of strike but go very gentle on the sparge and keep a close eye on the gravity of the runnings, and don't be afraid to stop and settle for less volume if things are getting marginal. I'd also take the boil fairly gently in order to try to get the evaporation less than 3 litres - that's not far off what I get on a 25 litre brew, and it's what is making your volumes challenging... however, that boil off is also going to drive your gravity up, so if you're over-target on SG but a bit short on volume then don't be afraid to top up with boiled/bottled plain water at the end.

 

[Tetsuo1981]

First of all, I'd say that water volumes can end up being somewhat specific to one's own kit and technique. However, within reason, if you wind up under/over volume then you can either carry on boiling a bit longer, or top up with a bit of (boiled/bottled) water.

In case it helps here are a few pointers based on my experience:

• typically it's easiest to start from the volume you want to end up with going into the FV ('batch size') and work backwards to the desired pre-boil volume (i.e. the amount you want to get out of the mash)
• remember that the volume of your beer will shrink by about 4% as it cools down, so don't be surprised if it looks like you've "lost some" compared to what initially came out of the kettle
• the amount that evaporates during the boil is hard to estimate, because it depends on how vigorously you boil and the surface area of your kettle
• I personally don't have any kettle loss, because I tip it all into the fermenter (obviously once I've filtered all the hop debris out)
• I always find I lose a surprising amount to the gunk at the bottom of the fermenter: you might find 1 litre a bit of a conservative estimate

OK so all that said, 16.5 litres looks about right for your pre-boil volume (although 3 litres is quite a lot of boil-off).

• you therefore want to get 16.5 litres out of the mash
• starting from your grain weight of 2.5 kg, you want to mash with about 2.3 - 3.0 litres of water per kilo of grain (so in your case, 5.75 to 7.5 litres of water). People will be queueing up to say you can go higher than that with impunity, but personally I wouldn't advise it.
• let's say you go with 3.0 litres per kilo: 7.5 litres of strike
• each kilo of grain will absorb something like 1 litre of water per kilo during the mash; so your first runnings will be something like 5 litres. You might get a bit more by squeezing the bag, but it could get a bit cloudy so don't overdo it.
• In that case, to hit 16.5 litres into the kettle you'd have to sparge with 11.5 litres.... which to me sounds like quite a lot of sparge for 2.5 kg of grain and you'd have to be very careful to avoid the gravity of the final runnings dropping below 1.010 sg.

If I were you, I'd stick with 7.5 litres of strike but go very gentle on the sparge and keep a close eye on the gravity of the runnings, and don't be afraid to stop and settle for less volume if things are getting marginal. I'd also take the boil fairly gently in order to try to get the evaporation less than 3 litres - that's not far off what I get on a 25 litre brew, and it's what is making your volumes challenging... however, that boil off is also going to drive your gravity up, so if you're over-target on SG but a bit short on volume then don't be afraid to top up with boiled/bottled plain water at the end.

Wow!! Thank you for the great in depth reply, it's really appreciated. I'll have a look at adjusting the kettle loss and evaporation figures (I thought that 3ltr was a bit steep for such a small amount). And take it easy with the sparge, originally I was gonnan just use 12.5ltr as it was half of what the recipe said and just sparge with a kettle worth of water.

Sadly the recipe video doesn't give any gravity indications aparf from the pre boil gravity so I've got that to aim to.

 

[The-Engineer-That-Brews]

Wow!! Thank you for the great in depth reply, it's really appreciated. I'll have a look at adjusting the kettle loss and evaporation figures (I thought that 3ltr was a bit steep for such a small amount). And take it easy with the sparge, originally I was gonnan just use 12.5ltr as it was half of what the recipe said and just sparge with a kettle worth of water.

Sadly the recipe video doesn't give any gravity indications aparf from the pre boil gravity so I've got that to aim to.

You’re welcome: but as I say, your mileage may vary… :hat:
Unfortunately the rate of boil-off is pretty independent of batch size so 2-3 litres wouldn’t be surprising; but of course with a smaller batch the effect on the SG will be higher so topping up after the boil might be more of a viable strategy.
If I were you I’d probably focus on getting a reasonable OG (say 1.040 to 1.045) rather than trying to hit a specific batch size - and do take really good notes so you can tweak things next time.

Incidentally, just in case of any confusion, I think that when people talk about ‘batch size’ they generally mean the volume into the fermenter, not the final finished volume into the keg/bottles etc (‘bottling volume’).

 

[Tetsuo1981]

your mileage may

If there's one thing I've learned so far in home brewing this that there's no truer statement than that!!

the rate of boil-off is pretty independent of batch size so 2-3 litres wouldn’t be surprising; but of course with a smaller batch the effect on the SG will be higher

Ok, that make sense more I think about it. Will go for a decent gravity over volume this time around, better to have s small amount of something drinkable than tons of rubbish.

I have found a copy of the Biabacus that I'm going to plumb the recipe into (I believe you can state your kettle size and it gives a close-ish approx of your boil off) but will keep notes as I go.

when people talk about ‘batch size’ they generally mean the volume into the fermenter, not the final finished volume into the keg/bottles

Yeah, again that makes sense too. Got to brush up on my BIAB terminology, with can kits I just make everything to 20ltrs and had at it!!

Thanks again for your help

 

[Tetsuo1981]

Ok, I've had a read around and and a play around with BIABacus and have come up with this:

Does this seem a bit more reasonable? I used the recipe from YouTube and also found a recipe that matches it which gave me OG and other info:
Stella Artois Clone | Bohemian Pilsener All Grain Beer Recipe | Brewer's Friend

So does this seem more realistic?

 

[The-Engineer-That-Brews]

Ok, I've had a read around and and a play around with BIABacus and have come up with this:
View attachment 67756

Does this seem a bit more reasonable? I used the recipe from YouTube and also found a recipe that matches it which gave me OG and other info:
Stella Artois Clone | Bohemian Pilsener All Grain Beer Recipe | Brewer's Friend

So does this seem more realistic?

I'm not familiar with BIABacus, but I'm a bit perplexed how it reconciles a 'total water needed' of 19.88 litres with a 'strike water needed' of 20.28 litres.
As it doesn't mention any sparge volume, I guess it's assuming you do a full volume mash. In this case (assuming you're doing half the recipe) that would be 8 litres per kilo of grain, which I would call very thin. I'm not saying it won't work, but the efficiency might be rather low and the beer might come out a bit sweet / low abv.

Each to their own, but I must say that if I were doing this recipe then I'd probably go for 7.5 litres of strike water (maybe up to 9.0) and then sparge carefully with 10 litres. If you're concerned about the sparging, maybe you could collect the first wort into a separate container, then refill your mash tun with 10 litres of fresh water, heat to 75ºC and then dunk the grain bag into it for 5-10 mins.

Also for my first iteration with a new setup I think I might try something a little more forgiving than a Pilsner, maybe a best bitter or a saison?

 

[Tetsuo1981]

I'm a bit perplexed how it reconciles a 'total water needed' of 19.88 litres with a 'strike water needed' of 20.28 litres

Yeah, that got me too, I might go back in and have a fiddle and see what I've possibly entered wrong

it doesn't mention any sparge volume, I guess it's assuming you do a full volume mash

Again that threw me so was going on that line of thinking as well

7.5 litres of strike water (maybe up to 9.0) and then sparge carefully with 10 litres. If you're concerned about the sparging, maybe you could collect the first wort into a separate container, then refill your mash tun with 10 litres of fresh water, heat to 75ºC and then dunk the grain bag into it for 5-10 mins.

This is probably what I'm going to end up doing so thanks for that

Also for my first iteration with a new setup I think I might try something a little more forgiving than a Pilsner, maybe a best bitter or a saison?

Glutton for punishment??? I guess I got lulled into the 'its a smash, it must be easy' mentality. Hindsight it a wonderfull thing

 

[Michael Burnley]

As this is your first all grain I would recommend forgetting about water chemistry for now and just do a very simple and cheap recipe, so that you can work out your water losses and efficiencies. If the worst case scenario happens and you have to write it off you haven't lost much. I very much doubt it will go down the drain and you will also have learnt a heck of a lot about your equipment and method so you can refine, dial in your numbers and then do the chemistry as you progress along.

 

[Tetsuo1981]

As this is your first all grain I would recommend forgetting about water chemistry for now and just do a very simple and cheap recipe, so that you can work out your water losses and efficiencies. If the worst case scenario happens and you have to write it off you haven't lost much. I very much doubt it will go down the drain and you will also have learnt a heck of a lot about your equipment and method so you can refine, dial in your numbers and then do the chemistry as you progress along.

That's what I was hoping to do by cutting a recipe in half. The biggest problem was the recipe in question didn't have any volumes apart from grain, hops and 'batch size'. I've just been trying to fill in the blanks with how much water to start with, sparge with, losses etc. Think I've got a better idea now thanks to research and helpful replies here when I get home tonight I'm gonna add the Biabacus spreadsheet for people to have a look at