Spreadsheet For Calculating Pitching Temperature

[BlueJ]

When we brewed our first beer, about a month ago, we followed the kit instructions and added 2l of boiling water to the fermenter. It was a warm day (around 28C) and we added 20l of bottled water that we had bought that morning.

The temperature when we pitched the yeast was around 31C!!! Now even I know that is warmer than needed and likely to result in unpleasant flavours in the finished beer.

The resulting beer is not all that great, and we partially blame the too-hot pitching temperature.

Of course, the 20l of water held a lot of heat, being a warm day. The kit instructions assumed that cooler tap water would be used.

On any given day, the volume of boiling water that you need to reach your desired pitching temperature will change, depending on the temperature of your other ingredients. You may find that you only need 0.5l boiling water...but how to know how much you need?

For our last two brews, I have used a spreadsheet to calculate how much boiling water I need to reach my desired pitching temperature, based on the actual temperatures of my other ingredients. I have found this to be a very useful tool, and quite accurate as well.

I have polished it up a bit and attached it here. Instructions and explanations are included. If anyone would like further explanation, let me know. I could post some screenshots into this thread.

I hope that the calculator can be of interest, and maybe even useful. Of course, I welcome all suggestions and other feedback - there are probably some errors and typos at least.

Cheers!

View attachment Pitching_Temperature_Calculator.xls

 

[Foz]

Wow - Well done! Just had a fiddle with it then and if its even close to accurate (like you say it is) it's quite the handy tool to have!

Thanks

 

[Hopeye]

Sorry, but, I seem to have lost the point on this one..... Is this an All-Grain stepped mash or something that a simple thermometer could tell you ????

Not wanting to sound facetious or anything.

 

[BlueJ]

Wow - Well done! Just had a fiddle with it then and if its even close to accurate (like you say it is) it's quite the handy tool to have!

Thanks

[post="122475"][/post]​

Thanks Foz, you're welcome! I hope it works for you. I have found it to be accurate to within 0.5C. Your mileage may vary!

Sorry, but, I seem to have lost the point on this one..... Is this an All-Grain stepped mash or something that a simple thermometer could tell you ????

Not wanting to sound facetious or anything.

[post="122481"][/post]​

Thanks Hopeye. It is for kit'n'kilo brewing and the idea is to tell you how much boiling water to add to reach the target pitching temperature, without being too high or too low.

Of course you could just use your thermometer and if your wort is too hot you could let it cool down.

In my opinion it is better to have the right temperature in the first place, and pitch the yeast straight away. I think this minimises the risk of infection, compared to opening the fermenter several times to check the temperature. Hence I use this spreadsheet.

Does this answer the question? I imagine that the same type of calculations could be applied for AG. But I am a long way off trying AG.

 

[Linz]

I used to soak the can in a small sink of hot tap water and mix the rest in cold tap water and always came up with 24oC finished temp....ready for pitching.

BTW ...the first few litres to mix in dont have to be boiling/hot water; its only suggested to make mixing the ingredients easier..

hope this helps too

 

[Hopeye]

Thanks Hopeye. It is for kit'n'kilo brewing and the idea is to tell you how much boiling water to add to reach the target pitching temperature, without being too high or too low.

Of course you could just use your thermometer and if your wort is too hot you could let it cool down.

In my opinion it is better to have the right temperature in the first place, and pitch the yeast straight away. I think this minimises the risk of infection, compared to opening the fermenter several times to check the temperature. Hence I use this spreadsheet.

Does this answer the question? I imagine that the same type of calculations could be applied for AG. But I am a long way off trying AG.

[post="122485"][/post]​

Hi BlueJ,

You are correct in that the correct temp is required for pitching yeast, regardless of how the wort is obtained. My question is: why would anyone need a speadsheet to tell them how much hot water to add to a can of malt when they will be filling the rest of the fermentor up with cold water. Mixing 1 - 2 litres of boiling water to a can of malt to dissolve to LME and filling up with cold water will generally be sufficient, except in the summer months when some ice maybe needed to be added. I just found when I was doing K&K brews it was easier for me to gauge the actual temperature from the digital thermometor stuck to the outside of the carboy than rely on what a spreadsheet told me from possibly wrong inputs (when I didn't know what the actual temperature of the tap water was that I was adding to the carboy). It's just I feel that it is not needed to get so scientific with K&K brews and there is no need to scare new brewers that they need to calculate the precise temperature to pitch the yeast. K&K brews are much like bi-wing planes, you have a lot of room for error as long as you watch your telltales. If you ignore your telltales (in this case, the digital thermo stuck to the outside of the carboy), then on your head be it......

I'm not telling anyone who wants to use this spreadsheet, not to use it. All I'm saying is that for K&K, why bother ??? Just get used to what has to happen and don't get bogged down in the science. I'm not yet into AG and I don't bother with a spreadsheet to tell me how much cold water to add to my Mini-mashes to bring it down to the precise temperature. The digital thermo tells me it's in pitching range and I'm happy.

Too easy.

Beers

 

[BlueJ]

All I'm saying is that for K&K, why bother ???

Why use a $1,000+ PC to calculate how much boiling water to add? Probably it is the engineer thing.

My long-term plan is to put the fermenter on the LAN, setup a web server and monitor temperatures and airlock activity from the office during the day.

Call me crazy, you won't be the first nor the last... :blink: ...engineers tend to have obsessive personalities. Or maybe that's just me?

 

[BlueJ]

I used to soak the can in a small sink of hot tap water and mix the rest in cold tap water and always came up with 24oC finished temp....ready for pitching.

Hi Linz

Here in Melbourne the tap water temperature varies greatly from season to season. This morning it was 15C, earlier in Autumn it was 20.5C.

And we use 10 litre bottles of 'spring water' rather than tap water, of course their temperature depends on ambient.

Reason: the brother-in-law has a theory. It is: if we use the same ingredients (eg kit, sugar, water) all the time and only change the conditions (eg ferment temp) we will learn about the effects that these changes can have on the finished product. Whereas if we change lots of things all at the one time - for example, we change ingredients and conditions - we won't know what effect was caused by what.

So we are assuming that tap water varies in its mineral content, which in turn may affect the yeast in mysterious ways. And we hope to avoid that by using the bottled 'spring' water (which probably varies more than Melbourne Water's finest anyway...).

Having said that, so far we have made a lager, a stout and are now making a wheat beer. So much for not changing the ingredients...

 

[Hopeye]

All I'm saying is that for K&K, why bother ???

Why use a $1,000+ PC to calculate how much boiling water to add?

[post="122534"][/post]​

OK. I'll bite. Why use a $1000+ PC to calculate how much hot water to add ?? You've got me stumped.

 

[BlueJ]

Hopeye, I love your avatar.

What can I say? Too much time on my hands?

Actually it just springs from a curious mind. In reaction to the 31C pitching temp of our first brew, as explained above, we decided the kit instructions (which specified 2l boiling water) were way off. I wondered if it wouldn't be possible to work out how much to add, dimly remembering long-ago lessons in thermodynamics and laws of conservation of energy?

Engineers have this thing about understanding how the natural world works. And understanding it means being able to predict it using a mathematical formula. The prediction of the temperature of a mix of brew can, boiling water and bottle water being an example of the natural world at work.

Turns out it is possible, actually easy with the help of Google. Of course, an EXPERIENCED brewer wouldn't need such a crutch as a spreadsheet to crunch the thermal numbers. I am not an experienced brewer.

 

[BlueJ]

Sorry, I don't mean to scare any new brewers that may be reading this. New brewers: don't worry about the 'science', don't worry about temperatures, just make the brew and enjoy. Or add ice as Hopeye suggests (damn fine idea, wish I had thought of that).


Think I need another beer now. Replying to my own thread is thirsty work!

 

[MHD]

Umm... just some minor problems with the spreadsheat...

I assume it is using heat capacity of the liquid to calculate the KJ in the wort... Well there is a problem... Using E=CT where C is the specific heat of the substance (Mass * heat capacity which) and E is the thermal energy (Heat is only a transferable quantity not a state quantity) T should be in Kelvin... The area this falls down is when you use a sub zero cooling water (aka ice) which has, miraculously -ve thermal energy...

Also, the SH of wort may be slightly different, but possibly not enough to change the calculation...

Cheers,
Scott
(Research School of Physical Sciences ANU)

 

[MHD]

btw... a few pale ales have been harmed in the making of the above post so it may not be entirely accurate... but the intent remains the same

 

[BlueJ]

Thanks MHD

I thought of the Kelvin issue, but it seems to work anyway. I rationalise it by thinking that the formula for heat content of water is only relevant for 0C to 100C only, and of course that is when water is water not ice nor steam.

Maybe I'll do a Kelvin version and see if it gives the same results. It may well, as we are only talking about the kJ delta between two liquids. Whether the delta is referenced from -273 or from 0, the delta is the same.

I won't do it now as too many Weihenstephaners "have been harmed in the making of this post" and it looks like we are as guilty of the wanton destruction of young beers in their prime as each other.

I also doubt that the SG differences are big enough to affect the calculations.

Was the weather as magnificent in Canberra today as it was here?

 

[hopping mad]

I notice a little bit of criticism of your work!

I'd like to say well done! Youve obviously put a bit of thought and work into you idea. Some people will benefit and some won't. Regardless, it's this type of in-depth thought and research that can often lead to discoveries that can benefit home brewers around the world.

What ever the out come it is certainly a good read.

 

[Fingerlickin_B]

I've always got a 4L of water in the fridge, a thermometer and a kettle on hand, so I don't need the spreadsheet, BUT...

Nice work man, I know people like stuff and this is the stuff you like.

No need to shoot the man down, he's just enjoying the art the way he wishes to.

Isn't life all about doing things your way (even if asking advice along the way (pun intened))? :chug:

PZ.

 

[Foz]

Well said hopping mad!

I've just read the thread since my last post and am at a loss to explain the criticism?

BlueJ has made a resource that anyone can use to their benifit - if that doesn't suit you because you would rather 'estimate' the temps then don't use the spreadsheet.

All i can say, as i've said above, is well done BlueJ, because of your hard work the rest of us (beginners) can put down a wort at exact temps (according to the yeast strand).

Well done - and if you have any other handy ideas make sure we all get to know them - because that's what this site is for, helping each other to come as close as possible to that unreachable 'perfect beer'.

 

[Mr Bond]

Wow ,you guys make K'NK sound scary,Glad I've moved on to AG(for simplicities sake) :lol:

Just kidding.Good work Blue J