Overnight mash temperature

[MikeW]

Hi All,

I would like to perform an overnight mash, reading previous posts on mash temperature I noticed someone had posted a standard deviation graph . From the ideal temperature it indicated higher temps produced a sweet, maltier taste with lower ABV and lower vice versa.

Now are these temperature characteristics based on the max temperature reached or the average during the mash or another black magic equation?

The brew in mind is a Boxcar Double Dark Mild with an 8.18KG grain bill.

My options open to me are ....
A. to Mash at 69 Deg for the 60mins then leave overnight. Then raise the temperature to 75 Deg for 10 mins.
B. Mash at 69 Deg then leave overnight, once again raising the temperature in the morning.

Would you experts believe I could expect the correct flavours on either plan. For me, taste is more important than achieving the quoted 6.3%

Cheers

 

[Rwilts]

The taste profile you mention is due to the mash temp, not duration as it's the conversion of fermentable sugars. Higher mash temp = more non fermentable sugars so more sweet and lower ABV.

So mash overnight at the indicated temp and mash out in morning, believe there are a few active overnighters on the forum.

 

[peebee]

You choose to mash overnight for convenience, not to improve mash efficiency (although you should expect a small increase in efficiency). Start a one-hour mash at 69C before leaving it overnight and it's unlikely to make a huge difference to the OG that it had at the end of the one-hour. The "alpha amylase" should keep going for the duration, but it's a fast worker and had most likely finished all it could do in that first hour; there's no point doing a "mashout", just get on with any sparge (forget option A). The "beta amylase" was already severely depleted after an hour and will probably manage at a gradually reducing performance for another 30 or 60 minutes. Some people do report mildly improved efficiency overnight (and mildly improved fermentability), but enzymes are not up to much for most of the night.

Mash enzymes permanently denature, they do not reactivate with cooling. The information you refer to about overnight mashing should detail how long effective enzyme activity goes on for?