Strike temp, mash temp, etc.

[JohnB]

Hi folks,
I hope my brewing terms are about right, and wondered if someone could point me in the right direction here, please? I am doing my Christmas stuff today, a brown ale and a golden ale. I batch brew, so I have a mash tun (30l plastic jobby) and a second plastic jobby to catch the (batch) sparge, and a third to collect the wort. I also have a boiler for me hot water.

Now I heat the water to around 80 DegC and this I think is the strike temp? which gives me a mash temp of between 65 DegC and 68 DegC. I sort of understand the workings of the alpha and beta amylase and how they convert starch into different sugars. BUT I see some folks change the temperature during the brew, increasing the temp as the mash takes place. I can't do this, and I rely on a lagged mash tun in which the temp drops from an initial 67 (ish) DegC to perhaps as low as 58 DegC - 60 DegC. how critical is this mash temp and am I compromising sugar conversion along the way? I did the starch test on each brew, but that has been discussed before on here aunsure.....

What is likely to happen with such a drop in temp over my 60 minute mash, please?

Regards,
JB.

 

[JohnB]

Ooops! I should say "Some folks change the temp during the mash phase" - not brew phase.

 

[Ciaran12s]

That is quite a drop in temperature for 60 minutes.

A strike temperature of 80 also seems quite high.

My strike temperature is usually 70-75 for a 63-68 target mash temp, depending on mash thickness and ambient temperature of course. If you are reaching the target mash temp with that strike temp then fair enough it's working.

I have no ability to raise mash temp throughout and so don't. I've played around with low 60 mashes and high 60 mashes but just aim for 65 now and it's working fine. I believe these different temp rests aren't entirely necessary nowadays as the maltster has performed much of what these rest temperatures are designed to achieve. The additional rests may improve the resultant brew but are no longer an essential step for the everyday brew anyway.

With an ambient temp of just above freezing and brewing in my shed, I expect a temperature drop of up to 3C. I've never had any noticeable desirable effects from this kind of drop and my effeciency is fairly consistent. Are you measuring effeciency?
Is it just a plastic fv you're using as a mash tun?

 

[JohnB]

Hi Ciaran, yes it's just 5 gallon plastic buckets, but I do try to lag as best I can with towels (when SWMBO is out! ). My mash temp varies as well with how big the brew is. big brews, i.e. 5 gallons holds the temp much better, at 23l batch I'm mashing 10lbs of malt with 10-12l of water. My temp at start today on a small batch of brown ale (10l) was 68 DegC, and the finishing temp 62DegC so it dropped 6 DegC. Maybe I'm worrying over much?

No I'm not looking at efficiency yet, I only just started AG brewing and made Oh, perhaps 5 or 6 brews, which I must say are improving all the time and my latest is a cracker!! The first one or two were a bit dodgy, then I tried Clibit's SMaSH brew and it took off from there. One thing bothered me was the high starting temp to get somewhere near the 65 mark at finish and if this is likely to bugger the enzymes doing the sugar conversion. I should look into doing efficiency stuff really I suppose.

 

[Bigcol49]

Hi!
Try insulating the bucket with exercise mats - if you don't want to fit them permanently, use bungee cords.
Stand the bucket on a piece of polystyrene packaging and spread an old quilt over it. Add anything you can to prevent temperature loss.
If you are planning a brown ale you may want to aim for a high mash temperature (up to 70°C).

 

[Ciaran12s]

Worrying too much is usually a given. If you're happy with your results so far you can't be doing too much wrong.
That temperature drop may produce a more fermentable wort than desirable, as @Bigcol49 says, for certain beers you want to mash high and maintain that temperature throughout for a sweeter, fuller bodied result.

Better and/or more lagging should help.

Different temperature rests are quite advanced. I'm on AG 17 or 18 atm and have no intention of going down that route as yet. My set-up doesn't allow for it and I'm not in a position to make that investment, my beers are getting better every time as well.

Like lots of hobbies homebrew can be one where you make good beer with the most basic equipment or spend 1000s on professional equipment. The most important thing is we're all enjoying it, the hobby and the fruits of the labour!

 

[prog99]

I use an old duvet to insulate my mash tun. Seems to do the job quite nicely.

 

[cushyno]

Using a coolbox as a mash tun I have found these measures made a difference to hitting and holding mash temp:

• Pre-heat. 3 litres of water boiled in a kitchen kettle, pour into mash tun, put lid on, swill it around and leave a few minutes. Drain/pour out.
• Insulate. Sit the mash tun on foam mat, polystyrene sheet, old carpet, layers of bubble wrap, or anything that will keep the base off the cold floor. Insulate the sides and top the same way. If you're brewing a small batch it will lose heat quicker. You could even cut out a circle of polystyrene to act as an inner lid and slide down inside the bucket, which should reduce the amount of heat loss through convection inside the bucket.
• Add less water than planned to the mash but hotter. Let's say for a 4kg grain bill and aiming for 65°C mash. Calculate your mash figures based on 3L/kg so that should be 12L. Instead only add 10L but at a slightly higher strike temperature (Brewers friend calculates 75°C but I add 5°C to get 80°C). Dough in and stir. Check temperature (let's say it's at 60°C). Add water steadily from there on continuing with hot strike water. If your temperature looks like it's climbing too quickly, stop when you get to the right temperature mash and add remaining water at 65°C. 1 part cold water to every 3 (summer) or 4 (winter) parts hot water at 80°C should get your Strike water to about 65°C.
• Don't keep opening the mash tun to check temperature. Only open once to stir at 20 minutes left. Every time I open the mash tun and stir I lose 2°C.

Doing this I don't lose any temperature between stirs. Last brew I omitted the stir and only lost 0.5°C over 60 minutes. The mash tun had an old down jacket wrapped around it and was sat on a 5cm thick sheet of builders insulation.
Best brew yet.

 

[Dutto]

MASHING TIPS

Strike Water = 2.6 to 3.0 litres per 1kg of grain.
(Note: Strike Water is normally at 80*C for higher end temperature mashes and when grain and Mash Tun are cold.)

Mash for ONE HOUR minimum at:

• 55*C to 66*C for a High Alcohol – Dry brew.
• 68*C to 72*C for a Low Alcohol – Sweet brew.

DO NOT exceed 75*C.
Stir Mash after 20 and 40 minutes.

Heat SPARGE water 80*C to 85*C. Note: Lower in summer!

Lauter until wort runs clear (using two jugs) and then Sparge at one litre per minute.

Stop sparge when Boiler reaches 30 litre capacity. (This is usually when runnings reach SG1.008 or below.)

 

[JohnB]

Certainly enjoying the results [hic] ... I think I may have hit on an idea after chatting to a mate last night and he says "Oh, somewhere in the shed I have an old brew belt, electric jobby with an element and ties to go round a FV ..." Sounds good to me, I'm picking it up this evening. I'm hoping this may help to keep my temps closer to the optimum. I've also now got a polystyrene pad about 2 inches thick for the base, and an old sleeping bag to wrap the mash tun in.

So mash temp controls, sort of, the alcohol and sweetness of a brew. I checked the SG of my last brew and at the end it came out clear but was below 1008, it was about 1005 - 1006. Is there anything in the wort at that SG that is not good for the brew - proteins, starches?

@Dutto Please correct if this is wrong - when I sparge, I hold the grain in a filter bag, it's a nylon brewbag, then open the tap and let the wort run through. The first litre or so I recirculate back to get rid of any grain and bits that have come through the bag, this also helps to clear the wort that comes through. Once the water has drained off, I then I get a litre jug and slowly pour hot water at around 80 DegC through the grain into the collector with the tap closed then once I have re-wetted the grain, I open the tap and drain of the water a second time. I normally do this 3 times and at this point I have almost clear water running through. Should I be running the water continuously, i.e. pouring in and draining off at the same time. Maybe I'm a bit too fast as well 'cos I tend to pour the water in, slosh it around a bit, let it drain off into the collector, then pour in the next lot of water.

Thanks, everyone for the idea's - I'll get there in the end.

 

[cushyno]

If your SG at the end - Final Gravity (FG) - was 1.005-1.006 that's a sign that your mash temperature was lower, maybe around 60°C. No harm done, it just means there were more fermentable sugars so you got higher alcohol and less body. It's still drinkable beer and shouldn't be any more prone to infection or off tastes.

 

[Dutto]

I've never used the BIAB method but what you describe fits perfectly with what I do with my "Coolbox Mash Tun". With regard to the "continuous flow" I think what you is doing is okay. (Other BIAB aficionados may disagree!)

The high temperature Sparge Water is so that the temperature of the grain-bed goes above 75*C and the production of sugar stops. (Apparently , as this is another thing that I read somewhere!)

 

[pms67]

electric jobby

Sounds sore