Mash schedule

[Matplat]

I thought I would be a bit technical and step mash my most recent Weizen.

I had intended on doing a protein rest at 52 for 10mins, Beta rest at 63 for 30 mins, Alpha rest at 72 for 30, mash out at 78 for 10.

I used a step mash table I found somewhere on here for this schedule.

I decided to pre boil my water, as some crap came out of the lines when I recirculated my strike water (to mix the sodium metabisulphite properly)

Unfortunately by the time I was ready to dough in, it had only cooled to 62 so I thought I would just omit the preotein rest and carry on with the rest of the schedule.

The beer has stopped now at 1.016, I am doing a fast-ferment test at the moment, but just wondering if this FG should be expected?

The grist was a simple 50:50 wheat/ale malt, and the OG was only 1.043. I dry pitched a fresh pack of MJ M20 bavarian wheat yeast which kicked off fairly smartly, and I aerated the wort by running through one of those taps that screw on to the lid of the cube.

Cheers, Matt.

 

[manticle]

If you rested at 63 for 30, then bumped it up and all else was equal, I'd expect 1010 - 1012. Caveat being I've not used that yeast. Next time drop the alpha rest to 69/70 though.

 

[Matplat]

Thanks Manticle,

Yeah I was thinking 30 mins at 63 should balance the 30 mins at 72 and result in something around the 1.012 mark, but having never step mashed before I wasn't sure.

This is the second MJ yeast I have used that has been difficult to finish... I will report back once the fast ferment test has completed.

 

[MHB]

Doing a protein rest doesn't affect the fermentability of the wort, just the size of the protein molecules (more smaller less large); Caveat being that if there was a lot of unmalted or a lot of undermodified grist a protein rest might make some more of the starch available to the Amylase for conversion to sugars. I very much doubt that this applies in your case.

Your apparent attenuation is only about 63% so no it isn't where I would be expecting it to finish at closer to 77% or higher (around 1.006-1.010). Wheat yeasts tend to be highly attenuateive.

The milling of your Wheat could have some impact, if its too coarse (which is often the case if people don't reset their mill and crack the wheat separately), you can get lower than expected extraction and its is possible to get a less fermentable wort (not highly likely and I would have to know a hell of a lot more about your system and process to give a better answer.

All I can really suggest is Temperature - you haven't said but we are getting to the time of year where it cools pretty fast at night, can upset the yeast no end - try warming up the fast test sample and if you haven't already make sure the main ferment isn't changing temperature too rapidly.
Mark

 

[Bribie G]

I believe that the Hochkurz mash does 40 minute rests.

 

[timmi9191]

The milling of your Wheat could have some impact, if its too coarse (which is often the case if people don't reset their mill and crack the wheat separately), you can get lower than expected extraction

As the grist is 50/50 wheat and ale, would this really make a significant difference?

 

[Matplat]

Hmmm...... the plot thickens.

I requested the coarse grind from hoppydays as that has worked well for me in other brews. But I did get worse efficiency this time around 65% IIRC, 1v recirc in a bigW malt pipe, mashed with 25l strike water and sparged with 9l. I put the efficiency down to doing a smaller sparge than usual, and not stirring the mash as much as I usually do, I digress however.

Temp shouldn't be an issue, got the STC-1000 taking care of that....

 

[MHB]

Wheat as it has no husk usually gives a higher yield than barley if its cracked properly.
Wheat is also smaller than barley, and a fair amount harder so it mills very differently.
If you had the grist cracked properly I would expect a lot higher yield (by around 20%). Order the same grain bill from Brewman and do everything the same if you want to see what a well done wheat grist should look like. I know he would crack the wheat separately and properly.

Where is your fast test is it somewhere warmer than the main ferment - it wont ferment faster if it isn't - and is it subject to day/night temp change?

Mark

As the grist is 50/50 wheat and ale, would this really make a significant difference?

Hell yes, the more wheat the bigger the difference it makes
M

 

[TidalPete]

Back in the day our Weizen expert Zwickel always recommended a 40-minute rest at 40 deg c especially when using 50% or more wheat.

 

[Matplat]

Yep fast ferment is out of the fermenting fridge in the nice warm garage that usually sits around 27 deg although with the cooler change, it may have dropped to 21-22 overnight, shook the crap out of it to encourage it along....

I was thinking about doing Zwickels schedule, but I couldn't quite bring myself to doing a 2 hour mash!

 

[MHB]

With modern well modified malts (both wheat and barley) a 40 minute protein rest would I think be excessive (all due respect to Zwickel) It simply isn't necessary and would be likely to reduce the head, given long enough the Proteases active around 50oC will reduce all the head building protein to peptides and although wheat has more to start with you can still break them down.
Considering the quality of malt available today and how well it is made, I am far from sure that on balance there are any benefits to mashing below 62oC. In other than all malt beers (i.e. using adjunct) there are very good reasons to do Glucan and Protein rests - there are some very good reasons not to when all the grist is malted.
Mark

 

[Matplat]

An article I downloaded about promoting banana flavour says this:

"At the beginning of the mashing process the temperature should be kept low at 30°C to
increase the activity of the maltase enzyme in a decoction mash system and increase the
glucose concentration (Figure 1). The greater the difference between the glucose vs. maltose
in the wort, the more ethyl- and isoamyl acetate will be produced by the yeast. One part of the
mash (25-30%) is then separated (thick mash) and heated up to a temperature where the ß –
amylase is active (62°C), whereas the second part (thin mash) remains at 30ºC, both for a 30
min time period. After that time they should be mixed back together to achieve a wort
temperature of 40 °C. This is the most critical step of the mashing process with the maltase
being active and producing glucose for the next 30 minutes. Skipping the ß-amylase rest, the
wort should be heated directly to a temperature of 72°C to activate the α-amylase. After
checking for a negative iodine reaction, the mash is heated again to the transfer temperature of
78°C."


This is for a decoction mash, but I would have though the same would apply to a simple step mash....

On a separate note, do you think 24 hours is long enough for a fast ferment?

 

[Black n Tan]

With modern well modified malts (both wheat and barley) a 40 minute protein rest would I think be excessive (all due respect to Zwickel) It simply isn't necessary and would be likely to reduce the head, given long enough the Proteases active around 50oC will reduce all the head building protein to peptides and although wheat has more to start with you can still break them down.
Considering the quality of malt available today and how well it is made, I am far from sure that on balance there are any benefits to mashing below 62oC. In other than all malt beers (i.e. using adjunct) there are very good reasons to do Glucan and Protein rests - there are some very good reasons not to when all the grist is malted.
Mark

I don't think it is a protein rest at 40C. The aim of the 40C rest is to hydrolyse ferulic acid to produce 4-vinyl guaiacol to give the beer some phenol character.

EDIT: the ferric acid rest releases ferric acid which can be decarboxylated to 4VG during the boil and more significantly during fermentation.

 

[manticle]

My memory of zwickel's hefe schedule was that p-rest was not used.
He used them for lagers.

As far as a rest in the low 50s goes - I regularly mash in at 52-55 but the mash remains there for about 5 minutes only.
Not necessary but definitely effective.

 

[MHB]

Malplat: - Here is a copy of the original article that you are referring to, It was designed to supply Glucose in a wort, Wheat yeast needs Glucose to make isoamyl acetate about 5% of extract gives the most Banana flavour/aroma, adding Dextrose as required is a lot easier. I even exchanged a couple of emails with Dr Sacher and he was quite emphatic that if it wasn't for the Reinheitsgebot he would be doing exactly that.
If you are thinking of spending the three hours needed to make it as a decoction watch the pH, Maltase is very pH sensitive, if you don't modify the pH it wont work or will work poorly, you will need to hall it back down from ~6pH to something more conventional before heating to you Amylase rests.
View attachment Wkeat Beer.php.pdf

B&T: - Yes/no and maybe Yes you can form some during a ferulic acid rest, it probably gets degraded/ejected in the kettle by the end of the boil I doubt you would be able to smell or taste any of the clove flavours in the unfermented wort.
The yeast makes the clove and phenolic that is in the finished beer, along with banana and a bunch of other stuff. good wort design will supply the yeast with the precursors that are required.

I'm a big fan of Banana in a heff and always add the glucose (dextrose) to maximise it.
Mark

 

[sponge]

Interesting regarding the addition of glucose to push the isoamyl acetate. I too am a fan of a nice banana hit in a hefe so may have to try this next time.

 

[Matplat]

Agreed, adding some dex sounds much easier.

Mark, when you say "5% of extract" does that mean you would sub in 250g dex in a 5kg grist?

 

[MHB]

If your OG was 1.050 5% of the 50 points (1.0025) should be glucose, its a lot easier if you think of it in oP (Plato)
Same OG 12.5oP, if your knockout volume was 23L you would have 24.15kg, the mass of extract being 12.5% of 24.15 = 3.018kg 5% of is 151g of glucose.
Remember that Dextrose is really Dexter rotated glucose monohydrate and is about 90% glucose and 10% water so you would add ~168g.
Reduce your target OG appropriately (or not we aren't talking about a lot of alcohol)
Mark

 

[Matplat]

So after 24hrs of 'fast fermenting' the sample has got to 1.014 which means it has definitely stalled, and hasn't finished. I've already tried swirling the fv (that never really seems like it would do much anyway) and it has been sitting on 20 the whole time anyway. Seems like my only option is to pitch the spare pack of brigalow yeast that I keep in the freezer for these occasions... just means I won't be able to harvest any yeast which is annoying. I like to get more than one brew out of each yeast....

Any other suggestions before I pollute my yeast harvest?

 

[Wall]

Probably already crossed your mind but sanitised spoon and big Ol stir has saved me before.

I really struggle to bring myself to do it though. Usually star San the **** out of the fridge and everything in sight first.