Robobrew Question?

[snidepath]

I just picked up the Robobrew with pump. I have some concerns about water calculations. I have read that the grain father calculator seems to be pretty spot on.

According to the grain father calculator, a 5.5 gallon batch with 13 pounds of grain and a 60 minute boil, should put me at a 5.13 gallon mash with a 2.67 gallon sparge. Seems off to me? Then again I'm brand new to all grain. Can anyone verify this?

Also, my backup plan is to just put a couple gallons of water into my fermentation chamber over night in case I need to add some water before I pitch yeast. I'm thinking that might be a bad idea since I won't have the boil to kill off any bacteria. I'm just needing some clarification, reassurance and\or correcting. Thanks guys

 

[MSK_Chess]

You need to know four things. How much wort you plan on fermenting (your batch size). How much dead space you have at the bottom of your robobrew. How much your grain will absorb and how much wort will evaporate during the boil.

[ame]https://www.youtube.com/watch?v=cQd7KOTBHIA[/ame]

 

[MSK_Chess]

You desire in your fermenter 5.5G US (20 litres)

batch size + dead space + boil off + grain absorption = Total volume

5.5G + 1G (assumed value) + 1G/h (assumed value) + 1.5G = 9G (34 litres)

total volume - mash volume = sparge volume

9G - 5G = 4 G (15 litres)

So in summery for a 5.5 gallon batch you need 9G total liquor, mashing with 5G and sparging with 4G

Naturally these values will be sightly different. You need to test your dead space and your boil off. You will come to be more accurate with experience for sure. Enjoy all grain it really is the biz!

 

[snidepath]

Boil off should be 1.32 gallons and dead space is 1.5 gallons

 

[snidepath]

Better yet, does anyone have an equipment profile for the Robobrew? I found one but it was calculated for 6 gallon batches

 

[MSK_Chess]

Boil off should be 1.32 gallons and dead space is 1.5 gallons

ok, awesome

We want 5.5 Gallon US in the fermenter.

batch size + dead space + boil off + grain absorption = Total volume

(Gallons US) 5.5 + 1.5+ 1.32 + 1.5 = 9.82 US Gallons total liquor

total volume - mash volume = sparge volume

9.82 - 5 = 4.82 US Gallons sparge volume

In summation

Total volume is 9.82 US Gallons
Mash volume is 5 US Gallons
Sparge Water is 5.82 Gallons

Sounds much more accurate than the original grainfather one which failed to take into account the profile of your own equipment.

 

[snidepath]

I really wish Robobrew would put out a calculator since I'm not 100% sure on my evap rate and dead space.

 

[MSK_Chess]

You can measure your dead space simply by filling it just above the tap with water and seeing how much is left after you drain it. Evaporation rate will need to be gauged over time. 1-1.5G/h seems a good place to begin though. You will gain experience, get to know your new equipment and eventually become cavalier about it!