Visit to DB breweries

Ken writes:

I’m back in New Zealand for a long overdue holiday and a visit to friends and relatives.

And since I’m here, I had to pay a visit to DB breweries’ Waitemata brewery to view the continuous fermentation system (cf). I wrote about cf earlier in this post.

The DB cf process was covered in brief in the earlier post. There are three main tanks. The tanks are all stirred to keep conditions homogeneous within each tank. The first tank, known as the hold-up tank, comprises 6% of the total system volume and blends vigorously oxygenated fresh wort (O2 25-45ppm) with actively fermenting beer from the second tank and recycled yeast to maintain a pH of <4.4 and ABV of >2.5%. Hold-up tank temperature is 9C. The cool, acidic, mildly alcoholic conditions help guard against bacterial infection.

Drawing of CF system at Waitemata Brewery


The second tank is 63% of the system volume and is where the bulk of the fermentation happens. The tail end of the fermentation happens in tank three, which is 31% of system volume. The second and third tanks are maintained at 15C. A fourth, yeast sedimentation, tank finishes off the CF system proper. The yeast is washed with cold sterile carbonated deaerated liquor and some is recycled into the hold-up tank. CO2 is collected from fermentation and used elsewhere in the brewery and packaging lines.

I was really struck by how small the cf system was. The total system volume was 2000hl it is capable of producing up to 50hl of green beer per hour, meaning a residence time of 40hours, although my guide on the day, brewery technical manager Doug Banks, said that the residence time is varied between 50 and 90 hours depending on demand. The green beer undergoes a continuous maturation stage for a further 40 hours to remove diacetyl and then is ready for preparing for packaging (I assume this means clarification, and possibly bringing CO2 levels into product specifications).  Traditional batch processes would need a huge tank farm to accommodate these volumes of beer (and in fact the Waitemata brewery does have a large tank farm because it also produces beer by the batch for different brands, notably Heineken). Before seeing it for real, I don’t think I’d really appreciated just what an enormous capital saving cf achieves. A quite physically small brewery could produce huge quantities of beer.

The other highlight of the tour for me was seeing the old brewhouse. It was built in art deco style and is a work of art as well as an impressive piece of engineering.

lauter tun with run off sample ports.
lauter tun with run off sample ports.
Steps up to upper level where the mashing and lautering happens.
Steps up to upper level where the mashing and lautering happens.
brewhouse control panel
brewhouse control panel

One interesting feature of the old brewhouse is a lactobacillus delbruecki reactor vessel for acidifying the mash. Lactic acid was produced in this vessel to bring the mashing conditions to optimum pH level.

Lactobacillus Delbruecki reactor
Lactobacillus Delbruecki reactor

It was a very impressive space. Beautifully uncluttered and beautifully designed and I can imagine it would have been a wonderful space to work. I don’t think the brewhouse is in regular use at the moment although it is still in working order.

I’m very grateful for the chance to view first hand a piece of New Zealand brewing history and happy to see one of New Zealand’s key innovations still going strong into the future. (Some people may be snooty and dismissive in a kind of reverse snobbery kind of way, but fermentation technology is in principle something every brewer can use provided they have the sales to justify producing beer in such large volumes. The details of the recipe matter for the earlier stages of wort production. Maybe in the future the likes of Brewdog or Sierra Nevada will use this technology for their flagship products).



Yoghurt and raw ale under the microscope

Ken writes:

The title is intended literally, I’m afraid. I got out my microscope today and had a little play around.

Yoghurt at 400x magnification
Yoghurt at 400x magnification

I first had a look at some of the boys’ yoghurt that they’d left lying around. I diluted with a little tap water and had a look. You can’t see too much from the photo. I think the debris you can see is probably some kind of protein. When I increased the magnification to 1000x I could definitely see motile particles, which I took to be bacteria (the rest of the field wasn’t moving so that eliminates the possibility that I just had too much liquid sloshing round on the slide). The little movers were pairs and chains of little circles (cocci?). I couldn’t get a decent picture unfortunately. The photos were taken with my phone, incidentally.

raw ale, iodine stain, 400x magnification
raw ale, iodine stain, 400x magnification

This one is interesting. I stained the slide with iodine, because I want to see if there was any unconverted starch in my beer. Unconverted starch stains black in the presence of iodine. You can see form this picture that there are indeed two lumps of it. The rest of the tattered looking stuff is protein, I think. A raw ale is one that hasn’t been boiled. It’s naturally cloudy because it still has a lot of protein in it. In the bottom of the picture, the circle with a thick dark outline is a tiny air-bubble. You can’t make out any actual yeast in this photo graph, but there were a couple of yeast cells visible in the live microscope version of this picture. Unfortunately, the iodine killed off any bacteria so I couldn’t see any little swimmers like in the previous picture. I think I will try to repeat this later without the iodine.


Ken writes:

Despite being a fairly middle of the road sort of person politically speaking, I sometimes get a bee in my bonnet about things. I’m tagging this post ‘Red Ken’.

My views have hardened on the subject of renting and letting property. While I agree that people should be able to use their property to make a profit, in certain cases that fundamental right needs to be balanced against other people’s rights. I would like to see a massive rebalancing of the legal framework of renting in favour of the tenants. Landlords shouldn’t be able to do whatever they like with property they let to tenants. Changes I would bring in include:- having the rental deposit held in a separate bank account controlled by a third party, so that the landlord must apply to retain the deposit at the end of the tenancy; security of tenure (rental contracts would be by default on a permanent and ongoing basis, with the tenant having the freedom to leave on a month’s notice, and the tenancy being protected under a change of ownership of the property); the tenant would be allowed to decorate the property; rent would not be allowed to increase at more than the rate of inflation during the tenancy and so on.
Continue reading “Landlordism”

some thoughts about whisky prices.

Ken writes:

After just over two months sitting on my hands after packing in the old job, I’m now gainfully employed again. Hip, hip… I’ve had a finger and a half of my special ‘getting a job’ Scotch which is about 30 years old and way out of my regular price range (but I won it as a scholarship gift). It’s truly a beautiful, beautiful drink, but I don’t think it’s so very much better than, say, a 15 year old whisky, or better enough to justify paying more than 50 to 60 quid. When it comes to pricing whisky (in this country at least) there’s a minimum floor created by the truly massive duty on alcohol which together with VAT amount to close to €14 per 700ml bottle. Then there is the fact that whisky is a very expensive commodity to produce, since it has to be warehoused for a minimum of three years in oak barrels before it counts as whisky (think how much vodka the distillery could have made in the meantime instead of making that bottle). So the manufacturer, distributor and retailer all have to make a profit out of the balance over €14. That covers production costs, wages, marketing, materials etc etc. A micro-sized distillery probably has to retail for €40 at a minimum to make any sort of return on investment. So basically €50 doesn’t buy you much of a premium in whisky. That’s just your average product. However, actual price is merely influenced by the fundamentals like duty and cost of goods to produce. it’s also affected by rarity and marketing. So the actual price can go way up. Obviously the older the whisky gets the rarer it is (because inevitably some whisky is sold young). The reason I say it’s not worth paying too much for whisky is that, in my opinion, the pleasure you get from whisky doesn’t increase in line with price. To a degree more mature whiskies taste better than younger whiskies, but only up to a point, and they don’t necessarily increase in proportion to the increase in cost. You’re not buying the sensation on your taste buds. You’re buying the right to have that sensation instead of someone else having it. The qualities of the sensation itself drop out of the picture. All this means: Don’t let the snobs fool you about whisky. Drink the stuff you like and the stuff you can afford and be happy with that. Sure, if someone gives you an expensive bottle, enjoy that too, but keep things in perspective.

Good Angry

Ken writes:

A few weeks ago while I was driving back to Dublin on a Friday I missed about five or six calls from my boss. I was driving so I couldn’t take the calls. Eventually, he switched and rang my understudy Chris who took the call and got the bollicking. I called and left a message on my bosses answer machine returning the call but he never called me back about it. I had to find out from Chris that he was upset because we had finished early on the Friday. He was out of order for many reasons. The first is that we had told his wife, Boss #2, that we were finished and leaving early and she didn’t object at the time. We can only assume they speak with one voice or else having two bosses is impossible. But secondly, he was out of order because we had in fact done all the work there was there to do. Boss #1 had said in the past that he didn’t want to be involved in the day to day running of the floor, because he works most of the week in Dublin, for starters. He has given that responsibility to me. And there was no more work to do. I don’t believe in engaging in pointless make-work projects just to make up the hours. Finally, no way should he be taking the matter up with Chris who was the person with the least input into the decision to finish early.

Anyway, there is a deeper reason why we were finished early and I wanted to address it so I called a meeting for the next available time (the following Wednesday) when all interested parties were available. At root the problem is that we are making more beer than we are selling. Sales and production need to be coordinated or else you get steadily increasing stockpile of beer that is slowly going off (You can’t keep beer from ageing and staling no matter how carefully you prepare it). The blame for the overproduction falls squarely with the bosses because they have been riding me and Chris hard all year to get us to produce more beer more efficiently. They also are the only ones with access to data on sales. So they should know how much they are selling. In recent weeks over production has meant that we have been relying on other breweries kegs to package our product which is akin to squatting in someone’s property rent free. We deprive them of the use of their kegs for weeks and weeks while our beer sits unsold in it. To top it all off, the sales/production thing could have been managed perfectly if they had been willing to brew on contract for other microbreweries (most Irish microbreweries don’t actually have breweries as such but exist as brands only, produced and packaged by someone else). We could have had a piece of that action, it would have allowed us to run the brewery at full capacity and most efficiently and selling the beer would have been someone else’s problem.

It was because we had been over-producing that there was nothing more to be done on Friday afternoon. I called the meeting because I wanted to put on record and let the bosses know that sales was the problem for the brewery at the moment. You can tell boss #1 and boss #2 these things but the is no evidence that they listen. I wanted to make a more formal representation and also to clear the air after the nasty business that had been the Friday afternoon telephone call.

Despite the fact that I’d requested a meeting on Monday morning, no body mentioned the Friday call or the meeting all morning and so after lunch I went to the office to ask for the meeting to take place. Boss #2 said boss #1 had gone off making deliveries so we couldn’t have the meeting. I wasn’t happy with that so I asked her to deputise for her husband. She said she would but must have called boss #1 because when we arrived in the meeting room fifteen minutes later she said boss #1 would be back at 4:30pm and had insisted that we wait until then. While she was saying this, boss #1 called me and launched in to a tirade. He was incensed that I had called a meeting and had insisted it take place. He was the boss. It was his company and we would be doing things his way. As it happened, a 4:30 meeting would mean that I would miss an appointment later that day, but apparently that was not important. In fact it didn’t matter because while he was on the phone, boss #1 became so overcome with anger that he had to turn the car around and return to the brewery to have the meeting.

Now there has been a general souring of relations between the bosses and the workers over the last few months (probably because they’re worried about sales and revenue). But I didn’t want to get into that in the meeting. I really just wanted to clear the air and make as plain and clear as possible that production cannot outstrip sales (it’s hard because you have to anticipate sales so you can have beer available for them. They have never managed to give me any sales forecasts and yet I am supposed to provide them with packaged sellable beer of every kind when they need it). Anyway Boss #1 opened the meeting by reading me sections of my contract where is says no premium will be paid for anti-social hours or weekend work. Why? because he wanted us to brew late one night the next week so that we would still be brewing in the evening when he invited some local area publicans and tradesmen to the brewery. As it happened, only one publican showed up, and none from the little village where the brewery is located (Irish publicans are a truly inspiring and imaginative group). I said my reading of that passage was that it meant I would not get paid extra for working any antisocial hours, not that I had to work them. The contract states I will work a 40 hour week as well, but it doesn’t say I have to work any period of hours that the boss decides. As far as I am concerned that is all subject to negotiation and I told him that calmly and slowly. Boss #1 ranted and raved and tried his best to derail the meeting and talk about everything except the production issues that we had put on the agenda. Throughout he was talking about it being his business and him being the boss throughout, which although true, doesn’t give him licence to play the tyrant.

I never raised my voice and I steered the meeting back to the agenda and I didn’t permit myself to saying that I would regret. I am not happy in the job, but I recognise that it has given me opportunities I wouldn’t otherwise have, and it also pays my bills. I didn’t just want to chuck that away because boss #1 is a prize twit. During the meeting, it felt great being angry. But not angry in a hot, can’t think or see the wood for the trees way, but in a cold way. I knew why I was there and what I wanted from the meeting, and what my goals and vulnerabilities were. Above all it felt like I was in control and I liked that. I’ve got to go back to work on the 5th. There will be new meetings in the new year. and although it is tiring and effortful to have to do so, I will be going in to bat for me and for the production crew on the floor and I will do it in the cold cold way I handled myself in that last meeting.

Coffee snobs

Ken writes:

People often scoff when they learn I drink only decaffeinated instant coffee.

‘Why bother?’

The funny thing about this attitude is that it does no justice to their own appreciation for coffee. It implicitly claims there is nothing of value in the experience besides the caffeine. But who would want to replace drinking coffee with taking a caffeine pill?

They are mildly physically dependent on coffee, but I am not. They do need the caffeine stimulation, but I do not. I get as much from a cuppa as they do because I’m not missing what is missing from decaff.

But can they scoff because I drink instant decaf coffee?

I would concede that instant coffee has less flavour than the proper kind. It's bound to because it is processed and exposed to oxygen. Even after just a couple of weeks, the flavour of a jar of instant coffee has dropped away noticeably. But at the end of the day, it's only a cup of coffee. It's not something that really matters.

The pleasure of a well made cup of coffee just doesn't count for much. Even if on a relative scale proper coffee wipes the floor with instant, the two pleasures are so far from what really counts in life as to be indistinguishable.

I used to be a bit of a snob about coffee. Now I think it's just a young man's thing. One adopts these positions as part of carving out an identity. It felt good to feel superior to other people and to think that my palate was capable of affording me higher and more noble pleasures than others were capable of. I think I recognise now that it was not that other people couldn't tell the difference, it's just that they had the sense not to waste time bothering about it.

Messing about with malt, or the problems of ensuring consistency in a small brewery

Ken writes:

When thinking about the malted barley we use in our beer, there are three fixed points to consider. We have to keep the amount of potential alcohol the same from batch to batch. We have to keep the colour the same, since people tend to notice things like changes in colour. And we have to keep the flavour the same. The amount of potential alcohol is determined by the yeast we use and the amount of sugar we get out of the malt. Maltsters supply spec sheets listing the LDK (litre degrees per kilo), essentially how many ‘sugar points’ yielded by each kilo of malt. A kilo of malt with an LDK value of 300˚, for example, would yield 1 litre of wort with a specific gravity of 1.300 or 10 litres of wort with a specific gravity of 1.030 (i.e. 1 litre with an excess gravity of 300, what I’m calling ‘sugar points’, or 10 litres with an excess gravity of 30 (30 sugar points). If the LDK values change, then it is a simple matter to increase or reduce the weight of malt accordingly to keep the original gravity, and there the potential alcohol content, constant.

Maltsters also provide values for the colour of wort made from the different malts. As with strength, colour adjustments can be made by increasing or reducing the proportions of the different malts as necessary to accommodate changes in the colour from batch to batch.

Unfortunately, there is no objective reckoning for taste. I don’t even know if taste follows strength or colour. If the recipe calls for a certain proportion of the sugar points to come from a certain type of malt, then because the brewer just has to take the LDK and colour of the malt as it comes, the mass of malt and therefore its effect on the colour of the final beer will be determined. On the other hand, the recipe could be turned on its head, and we could specify what proportions of the overall colour of the beer come from what malts. Just as before given the colour specifications, the weight of malt will be determined, and therefore, how much sugar will be obtained and indirectly the strength. In other words, if the malt varies, then keeping colour fixed may mean a change of strength and vice versa.

I don’t really know how to solve this problem. I can see why large breweries would want to dictate to the maltster what malt specifications they will accept. It would be so much easier to keep a consistent product if you could rely on colour and potential strength not changing.

I think I’m going to sort of assume flavour follows colour. I don’t know how safe an assumption this is, but at least some of the compounds responsible for the colour of darker coloured malts are also responsible for some of the malt flavours (Maillard reaction products). I’ll try to have the coloured malts contribute as much colour as they previously did, but I’m not going to try to keep the colour contribution of the base malt the same. Instead, I’ll just adjust the base malt however I have to adjust it once the coloured malts are calculated to keep the original strength the same. There’s no real principles behind this; it’s a compromise to meet competing desiderata.

crystal 150
(image of crystal malt nicked off the internet from somewhere and used without attribution or permission)