My first mash

[Alestar]

I've been homebrewing for a few years now, but yesterday was my first "real" attempt with mashing from scratch, rather than the "tinned extract and a few extra steeped goodies" approach that I have previously followed.

Running my figures through ProMash, I seem to have a mash efficiency (not brewhouse) of about 55%. I am aware of the dilemma between high mash efficiency and quality of output, but even so this sounds a little low to me. I was just wondering if anyone had any tips, or indeed if it is anything to be worried about!

My mash went something like this:

Mash tun - insulated "Cool Box" style.

Grain bill -
5kg Maris Otter;
1kg light crystal malt;
1kg wheat malt;
0.5kg Cara Red;
0.25kg Special B.

Water - no treatment, nothing fancy, just pure Durham tap!

I added 15 litres of water at 73 deg. C, for a mash temperature of 66 deg. C. After one hour I stirred the mash: temperature had dropped to 60 deg. C so I added 1.25 litres of boiling water to take the temperature back to 66 deg. C. After half an hour more, temperature had dropped to 61 deg. C and I collected the first wort, 7.5 litres at 1.083 SG.

I worried a little that the initial mash temperature may have been slightly low, so I decided to overcompensate for the second batch and added 10 litres of water at 76 deg. C, for a mash temperature of 70 deg. C. After a stir and half an hour waiting this had dropped to 63 deg. C and I collected the second running of wort, 10 litres at 1.048 SG.

Then to make up my boil volume of 30 litres, I sparged continuously (nothing fancy, a plate with holes in and jug of water job!) with 73 deg. C water for an additional 12.5 litres.

My total pre-boil volume of 30 litres was 1.045 SG (meaning the final sparging "averaged out" at about 1.020 SG by my rudimentary maths).

Just looking for any advice from old hands really. Should I worry about an efficiency of 55%? And if so, are there any "schoolboy blunders" immediately apparent from my method!

Cheers in advance for any help.

 

[Wez]

Hi Alestar

It's a nice feeling getting your first mash under your belt isn't it. :thumb:

55% mash efficiency seems a bit low - I would look at the temperature loss on the tun first you seem to be loosing far to much far too quickly - wrapping the coolbox in an old quilt works well, I wrap mine in a sleeping bag :grin:

I'm also a little unsure of your mash process - am I right in thinking you mashed, run off then mashed again?

 

[Parva]

I'm with Wez. I use a 'Thermos' cool box and over the course of 90 minutes lose little more than 1c, there's something wrong there. The total amount of insulation my coolbox gets is one cushion on the lid.

 

[MEB]

+2 for what Wez said. You shouldn't be losing that much temp that quickly. The mash relies on a constantly held temp to extract the required sugars. I too wrap mine up in a sleeping bag and i get -1C loss over a 90 min mash. I'd guess your low eff is due to the loss of temp during your mash period mate.
Good fun though isn't it? :thumb:
Well done for getting your first Ag brew under your belt-welcome to the dark side :clap:

 

[Alestar]

Yep, it feels good to look at the fermentor in the corner of the living room and think: "I remember when all that was grain..." :P

I did kind of mash, run off, mash again, Wez, yes. To be precise I was planning to just batch sparge straight away, but when I saw the temperature drop in the first instance I thought: "It can't do any harm to leave it for another half hour with slightly hotter water before running off the second lot of wort." Making it up as I go along a bit!

Anyway, thanks for all the advice! It sounds like I was trusting too much in the retentive powers of the coolbox, as I'd heard so much good about them. I shall raid the guest bedroom for a spare quilt next time as supplementary insulation (making sure SWMBO is out of the house first of course ). The tun is one of these, Mash Tun, and has a hole cut out of the insulation for the tap slightly bigger than the tap itself. I was thinking I might try and fill that in with Polyfilla or the like as well.

 

[bolty]

I've got the same exact mash tun. I just put a doubled up quilt over it, and round it, and hardly loose a degree! The main thing to remember is that heat rises, and the lid is not really that insulated (no polystyrene in it, just hollow plastic).

 

[tubby_shaw]

Extra insulation will help Alestar :thumb:
Just something else to consider, did you preheat the mashtun prior to adding your mash liquor?
Some of those insulated chests can absorb a lot of heat before they stabilise :shock:
It is a good idea to add a couple of kettles of hot water (which is then thrown away) or add your mash liquor 10 C hotter and allow it to cool to strike heat :thumb:

 

[Wez]

Good advice right ^^^^^ there :thumb:

I add 10c hotter and allow it to cool to strike temp.

 

[llannige]

Another one for the 10C hotter and cool gang. :thumb:

 

[Parva]

I have exactly the same mash tun also and the only insulation mine gets is a cushion on the lid and it loses 1c over the course of 90 minutes. Regarding doughing-in, I have the water in my HLT at 82c for all parts of the process. I don't preheat the mash tun, I half fill it with the 82c water, add and mix the grain and I invariably hit 67c-68c every single time. Come batch sparge time I fill to within an inch of the top with 82c and this gets my mash upto 72c-74c, leave 10 minutes, drain off and refill with 82c water again and usually end up at around 78c, leave 10 mins, drain off and boil. Works for me everytime. :)