Low extraction rate from back to back ales

[Liam Callaghan]

I have not done many ales for some reason in all the years I have been brewing, some at the beginning and then I have been enjoying all the varieties of lager, pilsner and blondes.  Yesterday I had the whole day free to brew after a week of additional chores and jobs that just couldn't wait...

Before I start, the system I run is the same as most other people but the way I run it is a little different than most and I do not get this issue with the lagers, so I am a little unsure why it occurred this time.  I have been experimenting (just for fun and to learn) on how to make beers faster, just pushing the envelope and see if I can still make a great beer. There is always room for improvement and I like to experiment.  This summer I have been looking at speeding up the brewing process and done very well with some great pilsners and blondes.   I would really appreciate some advice on why I got such and unusually low extraction from ale grains than I do from the pilsners and blonde grains.

The ales yesterday were brewed back to back, three 30 litre beers from 9:45 to 5:30pm including washing down.  A leffe blonde clone from Richard Stanners (the best tasting beer I have ever had), an ordinary bitter for the Limbo competition and and ESB.  All ran very smoothly, a few minor mistakes on the first one but happy with the days brewing apart from the low extraction rates.  I have two more to run tomorrow (Stouts) and want to up the extraction back to a satisfactory level.  

The single infusion mash for each was between 65-67 degrees using tap water with no modifications (I have never tried modifying the water although I have spent a little time this week looking at that).  Mash times for each was about 50 minutes.  Sparge extraction temp was 74-76 degrees and after 15 litres the mash was thoroughly stirred up again and left to run until clear before taking the remainder.  Boil and hopping was done over 40 minutes with a full boil up and full roiling boil for the full period.  Chilled to 24 degrees in 20 minutes and pitched into the fermentor etc.

I know the mash time and boil times are not traditional but I have used these and much lower all winter as I have experimented with lagers of all varieties and had some amazing results with very fast brewing times.  What I don't understand is the difference between the malts and why my extraction would be so low, around 65% as opposed to 80-85%.  The sparge extraction temp was a little lower than I usually do.  I usually run around 85 degrees.

The other difference I had with the sparge was that I filled the mash tun so I had a good 6 inches of head over the grain and let that run (I usually dribble the water in or keep the head down to 1 inch or so).  Stir and run again, adding the last hot water for the final 10 litres.  The grain was tasteless and seemed spent on all the parts I tasted so was quite surprised by the OG.  I couldn't find the iodine so couldn't make a check of the conversion which I am kicking myself for as I can't rule that out.

If I use the ESB as a base:-

4.5kg Maris Otter

1kg Carapils

0.5kg Crystal 40L

0.25 Special B

Cascade and EK Goldings hops mixed for 60m boil

Mash in at 13:20 65 degrees

Sparge complete at 14:10 with 76 degree extraction temp

15 litres extracted, stirred mash and left to run clear and a further 20 litres extracted.

Boil and hopping as per normal, I don't presume any of this part will affect the malt extraction so no need to go through that part.

Any ideas?

Happy to explain the back to back brewing method I employ if anyone is interested.

[Liam Callaghan]

Hmmm...  Was really looking for some help there.

I will try a 60 min mash and slow sparge at a higher temp today with a couple of stouts, see how I go.

[Dougal]

In a similar vein to Brett's comment, how much do you stir? If there's a lot of flour in your crush then excessive stirring can cause it to form a layer on the top which prevents even sparging of the grain. You should be able to see this when you drain the mashtun though.

I'd be inclined to agree that mash pH is the most likely explanation. Try a 90 min mash if you don't have the means to correct it.  

[MrC]

There's nothing obvious that I can think of to explain the different efficiencies.  My efficiency is pretty static regardless of the grain types that I use.  Some grains can be slightly different in size where the bigger grains will contain more material for conversion into sugars for the same weight of grain but that is usually factored into your brewing software with a gravity potential value for each grain.

Personally, I think the most likely explanation would be differences in your process or mash pH from the different grains.

Do you check pH?

[Doublehoppy]

Hi Liam,

Also, what about the crush? Any changes there? Do you buy grain pre-crushed or crush it yourself?

Brett

[Liam Callaghan]

I crush them at a friends place (my mill is ready now so they will be from home now).  Its just cracked not smashed and pretty much the same as my lager grains from the looks, about to chill batch #1 so will see.  Went for a 60 min mash for the first one and 90m for batch #2

Just about to turn the chiller on so will be back shortly, personally I think it might be the ph or a mixture of ph and mash time.  I usually measure the conversion but not always the ph.

[Liam Callaghan]

Well thats a bit better, 1.042 and anticipated 1.046 so maybe it was purely mash time.  I'll have to buy some more papers and iodine as I can't find it since I cleaned the workshop - knew that was a bad idea haha!

Really unusual to have the extraction change so much.  The difference between this mash and the three the other day was the malts (Special B, carahell and Carafa)  Not sure if they make a change to the ph.  Either way will look at changing my water profile from now on, especially if it improves the beer.

Certainly not a lot of flour Dougal.

I'll see how I get on with the 2nd batch shortly.  Very excited about this recipe :p

[Liam Callaghan]

Final stout out and all washed up - few beers to keep me going :p

1.061 for final OG expected 1.063 so very happy with that so seems a lot of it was the mash time.  A mate (Thanks Tony) came over and took a PH reading which was a little high at 7-8 but the extraction was ok, more to go it seems.

I'll make the same beers again in 2 weeks time and use a longer mash see if I get the right results.  I am also going to look at the water profile, hopefully will have that down pat before I brew the next lot.

Thanks for the help guys, much appreciated :)

Bit of pressure building on the belgian ales from the cultivated yeast too Dougal, airlocks are bubbling very slowly so I am just going to let them roll, hopefully full steam ahead by Monday night.

[Grant R Baker]

Looks like you have it sorted.

I thought your mash was a little short, some of mine are 90minute, but 60 minutes would be my minimum recommedation.

btw the sparge method of immersing the mash wet malts again in the 74-77C water is called Batch Sparging. (I've been using this method for a while now). Supposedly it is a very old method that a lot of the original English Ale brewers used.

"Hot sparge water is added into the Mashtun, the mash is restirred and then left for 15-20 minutes. It is then drain using the same method you would run then drain the mash."

Happy brewing.

[Liam Callaghan]

Thanks Grant, it did go better the second round.  

Having looking back on my notes My mash temps were lower than normal so I would have been mashing in the beta amalyse range which can take longer to convert than my normal temp which is within the range for the alpha amalyse, which could account for the lack of extraction.  Wish I had measured but can't turn back the clock...  

I normally mash for 60 minutes but I have been pushing the limits for a bit of fun and found I can cut down the brewing process quite a bit and still produce really good beers.  Been great when life is really busy.  Brew in the morning and still have time to play with Mrs C by lunchtime.  I usually test the mash as I go though, just can't find my testing gear since i tidied up...  Knew I should have left it a mess :)

I have mashed for as little amount as 20 minutes and made some really good beers, no off flavours at all.  Worth bearing in mind.  Saying that if you don't check you can sometimes get an unwelcome surprise.

I went back to fly sparging the second day and mashed at 67 degrees and kept it at a constant flow.  Although I often do this with a head of an inch or so water on the grain bed, so might be a bit of a hybrid?  The batch sparge was nice to do though, nice and quick.  I just wanted to rule out one reason why the extraction was low. How do you find the extraction from the batch sparge?

Might be a combination of all of them.  PH, mash time, mash temp and sparge method...  Either way, measuring conversion would have helped.

A nice learning curve which was really good.  Opened my eyes to water profiling and I found another sparge technique :).  Next time I will be running a water profile, mash temp will be 67 and I will track the conversion.  Should be sweet!

Once I run my next few batches I will write a thread on back to back brewing and speed brewing with some of the pitfalls.  I've had a few queries on it.  Not always with great results but I am still learning and changing my method each time.  I can obviously spend the time and relax and brew traditionally as well, but I like tinkering, its half the fun :p

[Grant R Baker]

Extraction when using batch sparging has been very close to target every time (often a little too high, buggar). I usually measure after combining the strike and batch sparge sweet water together and its is always close.

It is amazing how close in colour the batch sparge sweet water ends up when compared to the orignal mash sweet water. I must measure them both separately next time (it will be a while since both fermentor and carboy is full).

.

Batch sparging also means the sparge water should not be as hot as a Sprinkle sparge since you do not lose so much heat from the water during the the transfer from hot water urn to mashtun.

When brewing the lighter Ales and Bitters I keep the sparge water below 75C and go no where near the 80-90C my Brewmate software recommends for the Sprinkle sparge. Darker ales and I may go as high as 77C.

.

I read on a US homebrew form where a couple of guys where discussing the merits of two batch sparges after a mash to ensure the got a higher percentage out of the grains. Interesting idea but you can easily end up with too much water with not enough malt in it.

.

In the end Batch Sparging is a bit like BIAB where you soak all the grain in a mesh bag until you get the finial gravity you are after... it is what I use for my small 4litre test brews when creating new recipes (quick, easy and only one 8l pot to clean).

.

Yep tinkering is lots of fun. :-))

[Liam Callaghan]

Once I hav ironed out what went wrong I will try it as a comparison for a couple of batches.

 

Interesting idea making 4 litre recipe batches, never thought of doing that.  Great idea.

[Grant R Baker]

Cool.  I be interested to see how it goes for you.