Hello All, I just tried my first scotch ale, Yazoo's Winter Seasonal Scotch Ale. Okay so the bottle says it's made with Marris Otter and Crystal malts. Hello Wikipedia So according to Wikipedia, Maris Otter was created in Cambridge in 1966, had a low nitrogen content, and became popular in English cask conditioned ales. Awesome. It makes sense that it would be in a scotch ale. Wikipedia then says Crystal malts have a high nitrogen content, so some of their sugars caramelize during kilning and become unfermentable and the sugars end up in the final product, hence a sweeter beer. Got it. It makes sense that it would be in a scotch ale. Then Wikipedia's article on Mashing says that lower nitrogen grains are preferable for brewers and higher nitrogen grains are preferable for distillers. Okay. The picture is coming together. I understand why both would be in a Scotch Ale. Then it talks about how grains can be grown in low or high nitrogen soil. Double-u Tee Eff? Do most brewers take into account the inherent nitrogen levels of their grains, and also the nitrogen levels of the soil they were grown in? Are grains only grown in soils that compliment their inherent nitrogen levels, or are they also grown in soils that mute them? Thanks.
Chemisty (water, grain, yeast) plays a VERY big part in the brewing process. Larger breweries will be concerned with many chemical aspects of all ingrediants in their beer.
Yes- they will have access to reports from the maltsters that will give them the nitrogen level (expressed in percentage), among other key factors. This will help them determine if the malt will be suitable for use in their recipes, or what kind of process they will need to use. Nitrogen levels are directly related to proteins, which will impact body and head retention. You don't want to have too much or too little.
Nitrogen in the form of free amino nitrogen (FAN) is also important for yeast growth and health. Too much nitrogen and the beer will have haze. That is why adjuncts were used with North American malts when the German brewers came over in the 19th century, to reduce the haze and make clear beer. High protein malts will have more of the Amalyse enzymes that convert the starches to sugars.
If I had drunk craft beer in high school and been asked questions like this I might have paid attention in chemistry class and become an organic chemist Solution to the dearth of science graduates - make them drink beer and ponder the chemistry! But more seriously, has anyone ever come across a documentary on the chemistry of brewing? That would be something I would love to see.
As someone who grew up on a farm, high N gives you better yield of grain. And that's usually important to the fellows growing it.
I have a cousin who grows barley but won't attempt malting barley. That's because it requires the use of less nitrogen fertiliser to keep nitrogen levels in the barley within limits. This of course reduces the yield.Malting barley fetches a higher price but the maltsters in this country are extremely rigorous in their specifications and if they reject the crop he's landed with a reduced tonnage of animal feed barley. http://www.ukmalt.com/barley-requirements
You can download a PDF article entitled "Malt specifications & brewing performance” here: https://www.ibd.org.uk/cms/file/314 Some tidbits from the article: “The total nitrogen content – the higher the nitrogen the lower the extract.” And: “However nitrogen plays an essential role in the quality of the beer: • Nitrogen, in the form of amino acids, is required for yeast growth with typical values of 160 to 240 mg/l depending on yeast strain and wort gravity. • Hydrophobic nitrogen from the malt provide the beer foam and head retention in beer. • Some long chain polypeptides cause colloidal instability (chill and permanent haze) in beer and have to be reduced in the brewing process. • Proteins and polypeptides contribute to the texture and mouthfeel of the beer. Excessive removal leads to a thin tasting beer with poor foam. It is important to ensure a avoid excess nitrogen in the barley, but ensure sufficient of the nitrogen available is broken down to soluble nitrogen. The ratio of total to soluble nitrogen is an important indicator or brewing performance. Most of the nitrogen breakdown occurs during malting.” Cheers!
That's in conflict with the requirements of the Scotch whisky industry; from the Matlster's Association of Great Britain's website; For brewing in the UK normally 1.60% to 1.75% nitrogen (10.0% to 10.9% crude protein) is required in the malting barley to achieve the malt specification for most brewers needs. If the nitrogen content is too low then the finished malt may not match the needs of the brewer's yeast and other brewing parameters. Conversely the starch content in the barley reduces as the protein increases, and it is the starch which is modified during malting, and ultimately converted in the brewers mash tun into sugars, which the brewers yeast then converts into alcohol. Malt for export brewing requires higher nitrogen in the malting barley it is to be made from, usually in the range 1.70% to 1.85% (10.6% to 11.6% crude protein). This is predominantly for lager beer, and the higher protein content barley produces an excess enzyme level than is needed for malt starch conversion, which allows unmalted starch to be converted in the mash tun. Such starch can be in the form of rice, maize flakes etc. Malt for distilling is measured in spirit yield, the production of which requires a high starch content (and hence lower protein) in the malting barley. A nitrogen level of about 1.5% in the barley is considered optimum and will be the maltster's target, if the crop quality allows, but distillers will use up to 1.65% nitrogen content.
It should also be pointed out that the Brewers in Scotland don't do things the same way as the Distillers.
A lot of the nonsense uttered about Scottish beer results from confusion with the whisky trade.Apart from both using barley malt they have little in common.Scotch Ale and Scotch whisky are only geographically linked.
The same is true for the Kentucky Common, as people think it had a sour mash as the breweries were not far from the Bourbon distillers. Brewing records from 2 of the old Louisville brewers showed that it was mashed with a simple infusion. I enjoyed the links you and Jack posted.
