Mash/Mashout times

Post #1 made 3 years ago
I'm happy with my current BIAB process (90 min mash, 10 min mashout, 90 min boil), and now just trying to do small refinements and try gain some time back in my day.

My query is about mash/mashout timings, for example I currently do a 90 min mash, then add heat to the urn and wait 15 minutes to get up to temp for mashout (grain is in the urn during this stage), then a 10 min mashout before hoisting the bag. So all up it's 115 minutes for the mash and mashout phase.

Instead I was thinking of combining the mashout into the 90 minute timeframe. So mash for 65 mins, then add heat and wait 15 mins for it to get to temp, then mashout for 10 mins.

Any thoughts/comments as to whether this will cause any problems? Or a variation that will bring down the time but not mess with efficiency etc?


Post #2 made 3 years ago
Good question MD :peace:,

My brain is done in for today so I'm not sure if I'll come up with a quality post for you; it might be a bit of a ramble (maybe not?)...

Lots of BIABrewers have contributed their numbers to the thread called Mash Gravity Figures Needed for BIABacus.

In that thread, we were exploring whether length of the full-volume mash affects gravity. It does as a general rule. In other words, ignore any posts you read on the internet about most of the conversion is done in the first ten or twenty minutes and/or conversion is done when an iodine test says it is done.

That research, however, does not answer your question. Here is what I think, but don't know for sure...

I don't think your proposal would work as when you go to mash-out temps, you are basically finalising all mash activity. It is your full-stop to the mash.

If you wanted to save time, your first option would be to mash for 90 minutes and then just pull the bag. But, then again, if you have a pulley system, there is no harm leaving the bag in until you reach 76-78°C. You don't need to mash-out for ten minutes, just make sure the bag is well-agitated.


Another point to be aware of is that there are no hard and fast rules. For example, I don't think (but don't know as it would require too much experimentation) that you would sacrifice any quality with a 60 minute mash versus a 90 minute mash. The thread linked above though shows that you would sacrifice some efficiency.

There are a few brewers you'll see on other forums doing 20 minute mashes but when I read their posts, I know that the best of scientists. For example, they say it makes no difference to efficiency whereas we know that it does. I have also never tasted their beer. But, in saying that, maybe their beer is better, just costs a bit more grain?

To explore these sort of questions requires side by side brewing (same time, same day) of the same recipe several times just to start. After testing on one recipe (style) then you need to explore other styles. All of these need to be triangular tested by several brewers.

Experimenting properly is very hard. I've done it many times here but just end up with too much of the same beer!!!

One day though, I will do at least one side by side on a very short mash versus a 90 minute one. Your proposal though, good thought that it is, I don't think will be the best or first way I would go about shortening your brew day.

Last edited by PistolPatch on 02 May 2016, 19:46, edited 1 time in total.
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Post #3 made 3 years ago
As PP points out, we've done research here that verifies the benefit of a full 90 minute mash (plus it gives me more nap time) so I wouldn't go shortening the mash time. That said, you can shorten the mashout time. Once the mash hits an even mashout temp (@170F), the enzymes cease to function and you're good to pull the bag and go on with your day. I have not found any benefit to maintaining mashout temps for more than a minute or two. The biggest benefit of mashout temp is to thin the wort a bit more and make the bag drain slightly easier.

Do you employ no-chill? The biggest change I made to shortening my brew day was moving to no-chill. No need to sanitize a chiller, muck with hoses and water supply, etc. Just shut the heat off at end of boil, drain into cube, clean kettle, done!

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Post #4 made 3 years ago
Thanks for the reply, all good advice. I'll try a few of the suggestions listed and see how they go with my efficiency numbers.

Yep I no chill thughes, I also ferment in the same no chill cube to again save time on sanitising/cleaning a new container, I haven't noticed any issues with fermenting with the cold break included and it makes things very simple using the 1 container through the entire process.
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