Double Brewday 31/03/07

[Garth]

Done two brews today, another EB stout (I think it's the 4th one now) and a Spitfire clone, recipe the same as in the recipe section apart from using British Caramalt in place of the Toasted 2 row.

I seem to improved my efficiency and once again, it's something I read on here, cheers whoever put it here, I simply sparged a lot hotter than I have been doing, I had the HLT running at over 90 degreesC and kept monitoring the grain bed to make sure it didn't get too cold. The liquor coming out of the sparger and hitting the grain was a good 85 so I think this is where the better result have come from.

It's not for everyone, but anyone considering doing two brews one after another should go for it, if you time it right you can stagger the two schedules so that you are starting to mash the 2nd one while the other is finishing the boil and getting chilled. Less to clean up than 2 separate brews and only a quick rinse round everything in between rather than full scrubs and dries. Plus I keep all my stuff in the converted loft so it saves dragging it all down twice. Just have to remember to keep your HLT or whatever, full and hot.

[Horden Hillbilly]

I seem to improved my efficiency and once again, it's something I read on here, cheers whoever put it here, I simply sparged a lot hotter than I have been doing, I had the HLT running at over 90 degreesC and kept monitoring the grain bed to make sure it didn't get too cold.

I normally heat my sparge water to around 77-80c & my recipes are based on 79% eff, I am usually near enough spot on, only a degree or so either way. I may heat my sparge water slightly higher next ag brew to see if I achieve a better effiency.

Pleased it all went to plan today Garth.

[Garth]

Cheers Daaba and Horden,

I not definately saying that it was the temperature of the sparge water that did the trick, but it's the only thing I changed, and it does make good sense.

[notassuch]

Nice one Garth,

I'll definitely be considering two brews in one day in the future.
Really interesting stuff.
Congrats on the increased efficiency too!

Dave.

[SteveD]

I seem to improved my efficiency and once again, it's something I read on here, cheers whoever put it here, I simply sparged a lot hotter than I have been doing, I had the HLT running at over 90 degreesC and kept monitoring the grain bed to make sure it didn't get too cold. The liquor coming out of the sparger and hitting the grain was a good 85 so I think this is where the better result have come from.

Might have been me. The written wisdom is that the grain bed should be raised to 77c for run off and sparging. This is done for two reasons.

(1) Once the mash time has elapsed and you're ready to run off, if you don't raise the temperature of the mash bed, the mash reactions will continue until you boil, and may result in thinning out your beer more than you wanted to. All the starch would have been used up but the alpha amylase will continue to convert dextrin to maltose, increasing fermentability but reducing body. raising to 77c stops the a-amylase doing its dirty work.

(2) Raising to 77c increases the liquidity of the wort which helps run off. It may also help sugars dissolve in the sparge liquor more easily - possibly a reason for higher efficiency.

So, they usually say sparge at 77-80c. But, I think a mistake has been made, which has been handed down from beer writer to beer writer and perpetuated. Yes, there are lots and lots of repeated mistakes in homebrewing texts. Harwood, for one. Chalk for another.

Anyway the mistake about sparge temperature is this:- they say 'sparge with liquor at 77-80c' and not 'keep the mash bed at 77c'. There's a big difference. If have your sparge liquor at that temperature, and monitor the mash bed temperature, you'll find that your mash bed will actually cool to about 60c or below! In order to keep the mash at 77c I find I have to sparge with liquor at 90c or above - it must lose a lot of heat between the HLT and the mash. Probably worse with a spinny sparger such as I have owing to the fine spray, and the fact that I sparge with lid off.

To correct what I believe to be a mistake, the texts should say:- 'sparge with liquor at a temperature that maintains the mash bed at 77c'

Different mash/sparge setsetups probably produce different 'heat differentials', for want of a better term, between HLT and mash bed but I think my set up is pretty common. So, what I do now is this: Mash with a grist to liquor ratio a bit on the stiff side 2L/kg ish. During the mash I heat up the HLT containing more than the brewlength of liquor to hit boiling point at mash end time. Using the insulated HLT>mashtun pipe I then run boiling water into the mash, stirring and monitoring the temperature until I hit 77c. Stop. Put the lid on and let the mash settle for a bit. I then run off and sparge with a temperature probe (or thermometer) in the mash bed. I juggle the sparge liquor temp to maintain the mash as near to but not over 77c as possible.

The other advantage is that the left over liquor can safely be used for yeast starting and topping up because it's been dechlorinated, acidified, and boiled!

Of course..I could be talking b0lloks! It has been known before.

[Garth]

Anyway the mistake about sparge temperature is this:- they say 'sparge with liquor at 77-80c' and not 'keep the mash bed at 77c'. There's a big difference. If have your sparge liquor at that temperature, and monitor the mash bed temperature, you'll find that your mash bed will actually cool to about 60c or below!

that is so true, I've checked the grain bed before and it was a little over 60

anyway, if it was you Steve cheers, and thanks for the input

[delboy]

Seems to stack up, well spotted steveD

[spearmint-wino]

Its a weird one - it is also written that if you sparge with water that's too hot you'll extract astringent flavvours from the grain...? My last 2 brews I've made sure that the sparge water temp in the HLT doesn't exceed 80°c and the end result has tasted noticeably smoother with no harsh lingering bitterness...?

Again, I may be talking b0ll0x here...
If I remember (been in the pub all afternoon... Roaring Meg, MMMMM!) I'll give another go at a higher temp and see what my results are

[SteveD]

Its a weird one - it is also written that if you sparge with water that's too hot you'll extract astringent flavvours from the grain...? My last 2 brews I've made sure that the sparge water temp in the HLT doesn't exceed 80°c and the end result has tasted noticeably smoother with no harsh lingering bitterness...?

Again, I may be talking b0ll0x here...
If I remember (been in the pub all afternoon... Roaring Meg, MMMMM!) I'll give another go at a higher temp and see what my results are

You might extract astringent flavours if the grain bed gets too hot, yes. But, the same writers that are telling you to sparge at 77c to 80c are assuming that the grain bed is at the same temperature - which it definitely isn't. So when they say if your sparge water gets too hot - ie, over 80c - they think the grain bed is doing likewise, and warn you of unwanted tannins, other phenols, etc. What they don't realise is the grain bed isn't too hot - nowhere near.