Originally By Tony Ackland
MashingThis step converts the remaining starches to sugars. Heat the grain (and malt or amalyse) to 62-63 °C for 45 min to 1 hour (stir occasionally), using 4.5L water per kg grain, then strain out the grains (use a kitchen sieve), keep the liquid (the wort/mash). Some methods involve bringing it to temperature, then holding it there for 2 hours in a big pot etc in the oven. When straining out the grains, rinse them several times with a small portion of the wort to fully wash them clean. Take care when heating the wort - it will easily boil over, quickly getting you banished from the kitchen. Watch it carefully, and enjoy the aroma.
When due to separate the grains from the liquid (lautering), raise the temperature to 75-77 °C. At this "mash-off" temperature the wort viscosity is favourable for quick & complete separation, enzymes are mainly inactive, and bacterial action is precluded.
It can be a differcult exercise to rinse the grains - getting them to soak through a collander or using a brewers "false bottomed" pail. John V writes ..
There are two enzymes which convert the starches to sugars & dextrins. Beta-amaylase "chops" the long starch molecules in half into shorter chains, whereas Alpha-amaylase "breaks off" the branches in the starch structure. Working together they do a great job, and convert 60-80% of the available starch to fermentable sugars.
Of the malted barleys, their enzyme potency is (in decreasing activity) 6 Row by a country mile, then 2 Row, Pilsner malts, Lager malts, Ale malts then Viennas and then Munichs.
In this stage the diastatic enzymes start acting on the starches, breaking them up into sugars (hence the term saccharification). One group, the amylases, are enzymes that work on the more complex starches and sugars. The two main amylases are Alpha and Beta. Alpha works by breaking up long, branched starch chains at the branch points, leaving behind a variety of straight chain starches and dextrin-type sugars. The reduction of these large branched chains reduces the viscosity and "liquifies" the mash. Beta amylase works by separating these straight chains into fermentable maltose sugar units.
Alpha amylase also works by hydrolyzing the straight chain bonds, but it can attack them randomly, much as you can with a pair of clippers. Alpha amylase is instrumental in breaking up large amylopectins into smaller amylopectins and amyloses, creating more ends for beta amylase to work on. Alpha is able to get within one glucose unit of a amylopectin branch and it leaves behind an "alpha amylase limit dextrin."
Alpha-amylase works best between 65-67 °C, and dies within 2 hours at 67 °C.
Beta-amylase works best between 52-62 °C, deactivating within 40min at 65 °C.
(To understand how enzymes work, see Enzymes, a useful email from Stephen Alexander to the Homebrew Digest about enzymes, explaining how they affect the rate of a reaction, and how they work in the conversion of starch to glucose.)
You really need a mixture of the amalyses. Baker explains ...
An alpha beta combo will only give you a theoretical 42DE, if you add a pullulanase (a de-branching enzyme) it goes up to 50DE, and Alpha/gluco combo has a theoretical DE of 95.
By the was DE stands for dextrose equivalent, it is a measure of the percentage of glucose bonds that have been hydrolyzed. Pure dextrose has a DE of 100.
I'm pretty sure that Beano is a 1,4-alpha-D-glucan glucohydrolase (a type of gluco-amylase)
One of the things to keep in mind when you are thinking about what enzymes you want to put in your mash is what enzymes are commercially available. There are probably thousands of starch degrading enzymes out there, but only a handfull are produced industrially.
Let me back up a bit, there are two types of starch, amylose, and amylopectin. Amylose is a straight chain of glucose molecules, linked at the alpha 1,4. Amylopectin is a highly branched chain starch molecule, the straight part is linked at alpha 1,4 the branch points are alpha 1,6 linkages.
Wheat starch is about 24% amylose and 76% amylopectin.
Alpha amylase randomly breaks alpha 1,4 linkages
Beta amylase starts at the non-reducing end and breaks off two glucose molecules at a time(maltose). Beta only breaks alpha 1,4 linkages and so can chomp right through an amylose molecule, but will get stuck at the branch point (1,6 link) on amylopectin leaving large "beta limit dextrins".
Pullulanase is known as a "de-branching enzyme" it cleaves alpha 1,6 linkages leaving nothing but straight chains for the beta amylase to chew through. However you'll still be left with a wort full of maltose.
A gluco-amylase, sometimes called amyloglucosidase, will break both alpha 1,4 linkages and alpha 1,6 linkages leaving glucose (dextrose) molecules in its wake.
Since what you want to do is break down the starch and create dextrose as quickly and efficiently as possible my recommendation is to add alpha amylase and gluco-amylase together. I personally use a high heat stable alpha amylase to thin the mash and a gluco-amylase when the temp drops, I often add more gluco when I pitch my yeast just as a precaution. what the hell it can't hurt right?
Is the Pullulanase enzyme also in the malted wheat? No, but you don't need it if you're adding a gluco-amylase
The higher mash temperatures (65-70C) will produce dextrinous (heavy bodied beers, lots of "mouth feel") in a shorter period, whereas lower mash temperatures (62-63C) will produce more fermenatble (more alcoholic) beer over a longer time period. So go for 62-63C.
If you don't want to use malted grains, you can use amylase from a packet. Ted advises ...
Jack warns ...
The reaction taking place during mashing is one of hydrolysis and all the components of the grain particle are subject to varying degrees of changes. While the conversion of starch results mainly in fermentable sugars, the degradation products of the proteins and other components will ferment into fusel oils, aldehydes, esters and acids, which are grouped under the generic title of "cogeners". The composition and concentration of these cogeners determine the quality and characteristics of a whiskey. Thus corn, with its high starch content, provides the source of alcohol, while rye, with its high protein content, provides the "flavour". The variation of the respective proportions of corn and rye leads to different mash bills which exhibit different levels of flavour. The malt, with its unique function (to provide the amalyse to break down the starch), always occurs at a constant predetermined percentage, typically 10-12% of the grain bill.
Reese answers some common questions ...
Q1) I have thought about using a different corn - but would the chopped or cracked corn not behave in the same way as flaked corn? Would it not absorb the water in the same way, after all it is still corn starch?
It absorbs water, yes, but it only swells and remains relatively intact. Flaked corn, on the other hand, is corn that has been ground, rolled and then cut into flakes. When it absorbs water, it reverts back to its finely-ground state, hence your porridge problem. Chopped or cracked corn, while it absorbs water, will do so slowly, so you need to cook it longer and at a higher temperature. I kept my water at boiling through out the whole cooking process.
Q2) Also, I take it that you suspend the boiled cracked corn inside a feed bag during fermentation?
Yes. I have a large brewers bag that fits over the opening of my fermentation bucket, reaching to its bottom. After filling the fermentation bucket with sugar water, I line the bucket with the bag, cook the corn/malt and then simply pour it (and the excess water in which it was cooked) in. Then I tie the bag off with a loose overhand knot and put the lid on the bucket while it cools. It remains in the bucket and tied during the whole fermentation process. Afterwards, the bag will be emptied and washed for use in my next go.
Q3) How do you get the wort off the fermented corn - squeezing with your hands? Some sort of press? A lauter vat/set-up?
It should be possible to just simply rinse the bag with warm water, capturing what drains through. A good squeezing might help, but what you would get off wouldn't match the quantities of wort already suspended in the remainder of your now-brewer-bag-free fermentation bucket. The excess water that was available after cooking the corn/malt mix (and the corn's action on the wort while in the bucket) should have already contained enough starchy goodness to flavor the sugar-water wort base well enough.
Why don't you get as much as with a sugar wash? Grain is about 50% starch, and you're never going to convert 100% of that to fermentable sugars. If you convert 75%, you're doing well.
As for the iodine test still showing starch, there could be several reasons. Did you mix the malt throughout the mash (i.e. did all of the corn have a chance to get exposed to the enzymes)? Was your mash evenly heated throughout? Mixing/stirring to evenly distribute the heat is a good idea. You don't want hot spots destroying enzymes.
If you're making an all-barley-malt malt mash, you should sparge the grains out after mashing. Again, this is the way the commercial malt whiskey distilleries do it. However, keep in mind that malt mash does not undergo a kettle-boil the way an all-grain beer mash does, so you must limit the amount of sparge water you use or you'll over dilute the mash.
1.) Grains were boiled in the late 1,700's up through modern times by Belgian Monks and German Brewers. They were performing what was referred to as a "decoction" mash, which was used to guarantee a cotrolled mash temperature in the times prior to thermometers. Part of the mash (and a little liquid) was pulled off the tun and sent to the kettle, where it was brought to boil, and then added back into the mash. This doesn't kill the enzymes as they survive in the liquid part of the mash. It makes a great Bock or other fuller bodied lager.
2.) Brewer's boil their wort for numerous reasons, but mainly for reducing wort volume (and increasing sugar content), breaking proteins out of the wort for clearer beer, and for another extremely important reason......sterility. I get nervous when folks walk away with a snippit of info and fail with it. Yes, you can make a wash without boiling, but you are running some risks, sterilization wise, and will require an good size pitch of fast yeast to get things moving quickly. Even after boiling, I answer a lot of questions by Homebrewers who's wort has gone to mold even after boiling and pitching yeast. Long lag times produce off-flavors and and infections, and boiling helps at least to minimize what's carried over from the bacteria on the grains.
3.) Now, I will preface this by saying I'm no chemist, but it is our belief that you have to boil for quite a while......say 90 minutes at least and it's still a function of wort gravity.....to get even close to the type of flavors found in extracts. Extracts, so we believe, gets that band-aid type background from overworked melanoidens. These produce the type of extreme maltiness you feel in Dopplebocks and higher gravity beers. Extracts are just worked to hard to get them in extract form and in contest tastings I can taste them right off.
4.) Brewer's don't ferment on grains because it produces off-flavors as well as clarity nightmares. It's been written in brewing circles as well that fermenting on the pulp material produces methanol, though I have read to the contrary in (2) distillers resources that only pectins produce methanol. Since it is considered a "wood alcohol", we have always considered it as a byproduct of pulp fermentations. Though the "pectin" story seems to be spread throughout messages on this site (their source being the same (2) I've seen, no doubt), the Brewer / Engineer in me will stick with the logic that if fermenting on cellulose is a good thing, then we'ld all be cutting our trees down for hooch.
It may be true that some Distillers are boiling their washes and are fermenting on grains, I'm sure you'll find some that aren't. The use almost laboratory standards that we don't have access to. Further, their pitching rates / oxygen contents are much higher than the amatuer distiller.
I'm also aware that to ferment a beer on its grains would not only impart all kinds of off-flavours and undesirable bitterness from the husks, but it would engender yeast autolysis later in the fermentation cycle. And, for beer mashes, one definitely has to boil for about 90 minutes. This is not only important to achieve the hot break and to stabilize the flavour, but it's the only workable way to perform and control the hop extraction: bitterness, flavour, and aroma.
Having said all that, I must point out that in my last contribution I was referring to whiskey mash, and not beer mash. There's a significant difference in the two processes. Whiskey mashes that are fermented on the grains are high-adjunct mashes (typically 80+% corn, rye, or other cereal grains) and mashed to optimize fermentability. The mashing temperatures of around 65C (149F) for 60 to 90 minutes are more than enough to sterilize (i.e. Pasteurize) the mash.
Whiskey mashes are fermented from 60 to 84 hours, then they are strained and distilled. Given that the substrate is reasonably free of bacterial contamination (as it would be after 90 minutes at 65C) and that a copious and clean yeast starter is added, there's insufficient time for an infection to establish itself before the mash is brought to boil in the still. This is very different from a beer mash that has to undergo primary, secondary, and tertiary fermentation over numerous weeks, which would afford amply time for bacteria to thoroughly establish itself.
Whiskey made from mostly cereal grains are not only fermented on their grains, but in some pot-still bourbon operations that use steam pipes to heat their still boilers, the grain is even placed in the still. Now, a flame fired still could never do this without burning the suspended grist on the bottom of the still pot.
Malt-whiskey mashes are sparged the way beer mashes are, and are not fermented on the grains. But, they are usually not boiled, they go straight to the fermenter, are oxygenated, and are fermented for 60 to 84 hours, then distilled.
I hope this helps to clarify my prior contribution re fermenting on grains and not boiling.
A reliable source of a-amylase enzymes is ginger and I believe the inside white part of a banana skin. Also it is present in saliva but I don't like the idea of spitting into my wash. It replaces the function of 6-row barley or malting the corn. To prepare the ginger, add 1 cup of cold water (40deg F) and the ginger root into a blender and get it as fine as possible.
You can also use the mash 2-3 times or so I have been told. Some old timers in the woods here report up to 5-6 times. This suggests that they do not have an efficient starch conversion but they didn't use ginger either.
Use a paint strainer (or a stocking leg) as a bag to hold your grain. This solves the straining issue.
The A. oryzae is much more effective in breaking down the starch to sugar than malt. This is how the Japanese make Sake from rice. I believe the results are superior, the AO produces more pleasurable aldehydes than malt, and retains more of the corn flavor.
Additionally, as with sour mash, a little of the reserved ferment beer added to a new batch, alleviates the need for additional yeast or inoculants. Near continuous process! However, others have indicated that as batches progress, mutations can occur that will deviate from the original strains of both yeast and inoculants. Let your tongue be your guide!