A visit to Dingemans maltings

Dingemans is fairly small compared to some maltings I've been to, but I was delighted to see it had a malt roaster. Steeping, Germination and Kilning vessels can produce white malts (e.g. lager, ale, Vienna and Munich). But if you want to make crystal and roasted malts (e.g. amber, brown, chocolate, black) you need a malt roaster.

The grains are dried before storage and rehydrated in steep tanks. They have six 30 tonne steep tanks and two of 20 tonnes:

They do two steeps: five to six hours wet, eight hours air rest, five to six hours wet, ten hours air rest, before ending with the grains wet. The air rests stop the embryo in the grain, which needs oxygen, to thrive. Chalk is added to the first steep to bring the pH up to 10. The aerate the steeps by pumping compressed air.

They have 50 and 110 tonne Saladin boxes they use as Germination and Kilning vessels. The turners are moved through the grain bed to stop the rootlets tangling.

He was a Kurd you know

Only joking, the malting one was French

They are filled to 80cm deep. Germination is at 15 to 20°C. When kilning they run the turners through the bed five to six  hours into kilning to give good homogeneity. They can go up to 50 EBC colour in the Saladin boxes. They also have 25 tonne kilns for speciality malts.

It was the roasters that impressed me the most though. Having only seen pilot plant sized ones before something with a 20 tonne capacity was in another league. And they emptied it whilst we were watching.

It was pointed out that they can do three very different malts with 150 EBC colour, using the kiln, a crystal malt and a roasted biscuit malt. Which shows some of the limitations of malt analysis. They can make cara or crystal malts with colour of 20-350 EBC, the darkest Special B malt is roasted twice, the last 50 EBC of colour added after the first roasting and cooling.


Annually they produce 30,000 tonnes. 60% of their production is speciality malts, with only 40% white malts.









Thanks to Richard Rees for the pictures

Searching for clarity on unfined beers

At this year's Woking beer festival a number of unfined cask beers were available. Though some impressive claims have been made for the improvements in flavour that come from not adding finings to beer I'm rather dubious about them. As far as I know there's only been one paper published which compared the taste of fined to unfined beer and it found no difference. That's not to say there isn't any effect, but I suspect it's a minor one. To investigate this further I took the opportunity to do some more research.

The first beer I tried was certainly hazy enough that in normal circumstances I'd be eyeing it suspiciously.

There were no problems with the taste though. It wasn't outstanding, but there weren't any off flavours either. Another beer in the popular pale and hoppy style.

Much to my surprise the next one was crystal clear:

Some darker malts were used in the making of it but there was not the slightest hint of haze. Unfortunately it was a bit flat. Now I don't know it this was due to how the beer left the brewery or how the cask was handled at the festival. But I couldn't help but wonder if with an unfined beer this clear the yeast count was too low to get a secondary fermentation in the cask.

The last one I tried was a deliberately murky saison from a local brewery:

I've tried this one from the bottle with and without the yeast and I had to admit it tasted better with. It was also great in the cask and had plenty of condition.

So a bit of a mixed bag from this investigation. Not fining may improve some beers, it may make some worse, or it may make little difference. As ever more research is needed.

CAMRA and cask beer quality

A hardy perennial in the world of beer is people saying that CAMRA should focus on cask beer quality. The owner of Magic Rock brewery is the latest pushing this line in a Morning Advertiser article.

He bemoans the cask beer "discount culture" but is it really the place of a consumer organisation to try and raise prices? He also talks of cask breathers, which might help in some places, but old cask beer kept under a CO2 blanket is unlikely to be as good as fresh cask beer managed traditionally.

So what exactly can a beer consumer organisation do to promote beer quality? I doubt CAMRA members marching up to publicans and telling them where they are going wrong with their beer would go down well. And anyway isn't something like beer quality best dealt with by the industry, not consumers? Perhaps there could be an industry body to assess and accredit cask beer quality in pubs.

Oh, hang on.

However, perhaps CAMRA members could give scores for the quality of beer in pubs and maybe register it online.

Oh, hang on.

CAMRA members could then select pubs that sell the best beer, and the national orgaisation could then publish some sort of guide to where you can drink the best beer.

Oh, hang on. 

As cask beer is something really only found in pubs maybe CAMRA should campaign to promote and protect pubs.

Oh, hang on.

Perhaps CAMRA branches could run competitions at their festivals for the best beers in various categories, and on a national level overall champions could then be declared.

Oh, hang on.

I suppose CAMRA could get its publishing arm to produce a guide to how to look after cask beer.

Oh, hang on.

Come to think of it, although talk of CAMRA and beer quality does crop up regularly I'm not convinced there's much more they could be doing.

A visit to Westmalle brewery

I've read an awful lot of brewing text books and technical articles. I've also been to an awful lot of breweries. And I have to say the way things are done in breweries rarely matches with how things are written in text books. There are inevitably compromises that have to be made in production to ensure that beer can be made in the amounts needed and with the staff available. But not at Westmalle. The Trappist monks that have overall control of the brewery clearly don't skimp on investment and there was mightily impressed equipment, and an equally impressive commitment to quality from the staff.

The new brewhouse was shiny and automated:

They have a brew length of 200hl and brew four times a day, Monday to Thursday. They use three types of malt and six varieties of whole hops with some CO2 extract for bittering. An interesting point was made that it's easier to assess whole hops for disease compared to pellets. About 10% sugar is used and three hop additions are made during the boil. Three beers are made: Dubbel, Tripel, and Extra at 4.8% which is made for the monks. Triple now accounts for 70% of the 130,000hl produced annually. 

The brewhouse has an MCV and lauter tun. They also have an energy storage tank and a pre-run vessel and the wort is heated to 97°C before entering one of the two copper. Evaporation is 7%. As they use whole hops they also have a hopback.

The old brewhouse was also shiny but less automated:

The wort is aerated to saturation and the 400hl cyclindro-conical fermentation vessels are not too high so ester formation is not inhibited. The beer ferments down to 1004 and it is increased by sugar addition to 1008.5 on bottling. The beer is slowly clarified in 800hl maturation tanks: five weeks in vertical tanks or three weeks in horizontals. After maturation the beer is centrifuged and then re-seeded with the same strain of top cropping yeast.

We got to drink some beer from the FV which I have to say was rather good.

We were also offered the chance to have a drink of the yeast. I declined though others were braver:

Note this is George drinking the yeast, not the beer

 The bottling line dates from 2007 and runs at 45,000 bottles per hour.

The carbonation is 4g/l on bottling, which rises to 8.5g/l after 18-21 days of conditioning at 22°C in a warehouse where 50% humidity is maintained.

There was beer and cheese laid on after the tour:

 

So I had to try the Extra:

And the dubble. Oh yeah, and more of the tripel too.

Thanks to Richard Rees and Toni Ryman for the pictures

Brewing Microbiology for small breweries

An advantage of being back in civilisation is I get to go to IBD meetings. The latest one at HQ was on "Laboratories in the small brewery". Marilyn Seedhouse gave a detailed, if rather rushed, talk on brewing microbiology, and Lee Walsh of QCL touted his "BeerLab Analyser".

As the microbiology covered a lot in a short time here's the slides (well, most of them) with my comments.

I think we're clear here that microbial contamination is a bad thing for beer.

Ah, Bergey's Manual. That takes me back. Microorganism have names based on latin or greek and I never studied either. They can be awkward don't be intimidated and just press on doing your best. If it's any consolation apparently the latin or greek is often bad.

There are good points here like brewing there are a lot of steps involved in microbiological investigations. And also like brewing they can seem complicated at first but get much easier with practice. Aseptic technique and using a microscope might take some getting used to but it's worth it.

This is pretty minimal and you can even get useful results with less. I've seen small labs actually using a pressure cooker as an autoclave and you can incubate cultures at room temperature if needs be.

It seems a bit steep to have to fork out for methods, but if you can get help from someone they'll probably be happy to let you copy theirs.

The important thing is make sure you sample is not contaminated by anything else, or you results will be useless.

You can use 70% methylated spirits (70% actually works better than higher concentrations). Sadly HMRC don't seem keen on people using ethanol as a disinfectant nowadays.

We were shown how to take sample from a sample tap by spraying on alcohol and flaming first.

And how to use a long handled sample pot.

As well as how to sample though a rubber diaphragm (which are sometimes found for example on pipes).

Once the wort has cooled it becomes susceptible to microbial contamination, so samples need to be taken from the paraflow onwards.

Methylene blue staining can be used to determine the viability of yeast, but microscopy of yeast samples is of limited use for detecting contamination. With practice you can spot contaminants but it's not the most sensitive method.

Acid washing works wonders for getting rid of bacterial contamination, but won't help with wild yeast infection. Yeast academics tend to rail against the harm it does to your pitching yeast though this may be strain dependent and I've used it successfully in the past. After acid washing the yeast should be pitched immediately.

  Propagating your own yeast is a bit more involved than opening a packet and rehydrating.

Beer is actually quite inhospitable to most microorganisms.

Microorganisms are not very big and can grow quickly.

When looking for contaminating microorganisms just looking to see what grows is not very useful as in a brewery what you'll mostly grow is the pitching yeast. So selective culture media which suppress the growth of unwanted organisms (in this case generally brewing yeast) and encourage the growth of the contaminants are used. The suppression can come from adding things like cycloheximide (which will kill yeasts) or having limited nutrients available which only some organisms can use. The encouragement can come from optimising the nutrients for the organism you are interested in and providing optimal growth conditions (e.g. in an anaerobic environment provided by a gas jar).

You can get antifoam to add to culture media if bubbles are a problem.

Most types of culture media can be bought pre-prepared in dry form from companies like Oxoid.

Some more details of culture media used in brewery laboratories. 

You can buy disposable plastic spreaders too.

Other methods are also available. Membrane filtration is particularly useful when looking for low numbers of organisms in liquid, and she also mentioned that if looking for contamination in gas the gas can be bubbled though saline and the saline then membrane filtered.

Reading culture plates and identifying the organisms on them does take practice, but once you've got your eye in you can often be very accurate just looking at the colonies.

Some culture media will do things like change colour with pH which can help identify organisms.

I won't go on about the BeerLab analyser as there's a report by an ex-colleague of mine here.

Limits to the craft beer price premium?

When I was last in the lake district perusing the beer range at Booths was a regular occurrence. I was interested to see they'd got beers in from Mikkeller, but after looking at them I decided not to buy. And I suspect I was not the only one.

Over the course of the week I didn't see any gaps appear in the blocks of beer on the shelf, so I suspect that other people came to the same conclusion. The beers weren't particularly strong (4.6 and 5.0% ABV), or (at least to me) particularly interesting, and perhaps crucially were over £3 for a small bottle. Though small craft beer cans and bottles generally sell for similar prices to beer in 500ml bottles breaking the £3 barrier seems to have been a price premiumisation too far, at least for a supermarket.