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As promised, this time we're going to look at the Wittemann process in detail.
It was named after the firm which produced the equipment, the Wittemann Company. I was surprised to discover that they're still making CO2 recovery systems. Though they are no longer an indpendent company, having been bought by the Danish firm Union Engineering A/S on 1st April 2013. Oddly, their website states the process was first developed in 1912, five years after this article was written.
This is a brief descroption of how the system worked:
"No doubt, most of the gentlemen here are familiar with what is known as the Wittemann process. There in nothing particularly novel in the process itself, but it is for the special plant and appliances for carrying out the system of gas collection and reabsorption by the beer that the firm lay claim to, and I believe they are perfectly justified in their contention, from what I have seen of the plant.
When in New York I called on Mr. Wittemann, who gave me an introduction to the proprietors of a large ale brewery where their plant could be seen in full work.
As Mr. Wittemann explained, there are numerous ways of adapting or using their plant to suit the requirements of the respective users. Therefore, I shall just explain the working of this plant as I saw it in this particular brewery."
Journal of the Institute of Brewing, Volume 13, Issue 4, July-August 1907, page 363.
And here's the detail of what they did at this particular Ale brewery:
"They pitched their worts in open vats, just in the same way as we do. In about 36-48 hours after pitching, or when the fermentation has got a good hold and is giving off gas freely, a portion of the wort is run off to a closed-in vat (of which they had several). They only ran enough into these closed-in vats that was required to give them enough CO2 for carbonating purposes.
These vats were filled almost full, and were fitted with a 0.75-inch vent pipe on the top, through which the remaining air was expelled as the gas collected in the space at the top of the vat. The vent pipe was left open until the brewer considered what was the right time to start pumping the gas off. This he determined by the aroma or smell of the escaping gas.
The brewer assured me that the time when the gas was collected from the fermentations was the all-important part of the whole business.
When the right moment had arrived the vent pipe was closed and pumping commenced, and continued for 12-18 hours as the ease may be, when they would go on with another vat, and so on, until they had as much as required, or that the steel storage tanks were full.
It is at this pumping stage that the special plant manufactured by the Wittemann Company plays an important part.
The gas during pumping and compression is kept as cool as possible, so as not to destroy any of the natural aroma or ethers contained in the CO2, and to facilitate that the storage cylinders are large, and the pressure not allowed to exceed 200 lb. to the square inch.
The beer, after having the gas collected from it, is run along with the other fermenting beer to dropping vessels to finish."
Journal of the Institute of Brewing, Volume 13, Issue 4, July-August 1907, pages 363 - 364.
Is that clear? Most of the beer still underwnt an open feermentation and only a small amount went into the special Wittemann vessels. It's interesting that they wanted to retain more than just the pure CO2. Did they really retain the natural aroma?
Even more fascinating is that this brewery was using the dropping system. It seems to have been reasonably common in North America. I'm quite surprised by that. I wonder if any breweries had union sets?
http://2.bp.blogspot.com/-1-0VoKeJ3j..._Stock_Ale.JPG
The advantage of the system was the time it took to ferment beer was much shorter:
"The fermentations at this brewery were far quicker than the others, for in six days from pitching the beer was run direct from the fermenting vats to a quick chilling machine, and afterwards through the special type of saturator or carbonator, when it was saturated with its own natural CO2 and finally filtered brilliant and racked or bottled as required.
Broadly speaking, in eight days from pitching, the beer was on the market.
There was no storage in cold cellars. This fact alone means a great saving in the locking up of capital, also in capital outlay for the building and equipment and the maintaining of large cold storage cellars. But still, in my opinion, that was at the expense of the quality of the product."
Journal of the Institute of Brewing, Volume 13, Issue 4, July-August 1907, page 364.
Being able to sell beer just eight days after pitching is impressive. That's about the same time as it takes to produce Mild. But here'sthe most important question: how did the beer taste?
"The process is very quick, and moderate storage would probably have given a better beer.
The beer did not impress me. When sampled it had a very new, soft, soapy taste, but a very nice and pleasant aroma, the latter due, no doubt, to the fact that it had been carbonated with natural CO2. There was a marked difference between the draught and the bottled beer. Although it was the same beer in cask and bottle, the draught ale was by far the better of the two. The inferior flavour of the bottled beer I put down to the effects of pasteurising, although I had not noticed such a marked difference in the other brewers' bottled beer which had gone through the process of pasteurising.
I may say here that it is the rule to pasteurise the bottle goods at all the breweries, either ale or lager, both in Canada and the States. Although it enhances the keeping properties, it certainly deteriorates the flavour."
Journal of the Institute of Brewing, Volume 13, Issue 4, July-August 1907, page 364.
The answer: not that great. Especially after being pasteurised. You can tyell the author wasn't a fan of pasteurisation. I think the methods they used in the early days of the process "cooked" the beer more and were more injurious to its flavour than those of today. Still not a huge fan of it myself.
That difference between bottled and draught beer - the former pasteurised, the altter not - was true all through the 20th century, and is still the case with American industrial breweries. Though there have been odd examples of unpasteurised bottled beer, such as Miller Genuine Draft.
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