Fermentation time

[Baron]

Hi All
First up I am an all grain novice for distilling. My son is full on all grain brewer. We have just mashed milled malted grain to distil for the first time and produced about 100L of wort. I have distiller's whiskey yeast to pitch which I am going to do in 4 x 25L washes.
My question is when will I know when the fermentation is complete? Do I use when the airlock stops bubbling, when it reaches aa specific SG or as I have seen in some places after 72hours and no longer than 80hours.
Any advice you can give me will be greatly appreciated.

[bluc]

Take readings with a hydrometer. When the mesurement remains the same for consecutive days its done.

Or use your senses. Listen for fizzing, if fizzing not done taste it is it dry and sour? Then it is done..

[hjubm2]

As bluc said, check the gravity to see how far through the ferment it is. I cheat with mine by adding an iSpindle at the start of fermentation these days. Usually taking about a day & a half for fermentation to finish so if I do it one weekend it's ready to run by the next

[howard]

also, the lack of bubbling and the reaching of a desired FG is not definitive.
the yeasties are cleaning up after fermentation has apparently finished.
an AG man should know that ;-)

[Yonder]

Depends on what you’re making and how. If you throw your pH out of range you’ll stall the ferment, for example. Make your li’l yeastie beasties unhappy by not supplying proper nutes and they won’t help you make your nice product. Using a hydrometer to get a steady reading is good, getting to 1.000 or .998 is better. But that won’t work on things like a good rum. Too much muck to get a proper reading. Taste it. If it’s sour okay. If its even a little sweet, keep going. Make it, check it and come back in around 4 or 5 days and check it again. Enjoy the process, learn along the way, don’t be in a rush.

[Baron]

Make your li’l yeastie beasties unhappy by not supplying proper nutes and they won’t help you make your nice product.

Should I be adding nutrients before I pitch the yeast? What would you suggest and what quantities? As I said I am a complete newbie to all brain washes.

[GrumbleStill]

Make your li’l yeastie beasties unhappy by not supplying proper nutes and they won’t help you make your nice product.

Should I be adding nutrients before I pitch the yeast? What would you suggest and what quantities? As I said I am a complete newbie to all brain washes.

Not necessary mate. A good all grain mash has all the nutrients the yeasties need. Extra nutrients are typically used for sugar washes, rum, fruit wines etc.

Have a chat to your young bloke, as an all grain brewer he will be all over this stuff. As a beginner, a pH meter (or simple test strips from Bunnies) and a hydrometer will tell you if it’s healthy and when it’s done, once you get the hang of it, your senses will do the same job.

If you’re keen on all grain, I’d highly recommend getting a copy of Palmer’s “How to Brew”.

Cheers