本帖最后由 davidduan 于 2017-7-3 17:05 编辑
在http://www.homebrewtalk.com/forum.php论坛看到一篇，干酵母常见问题的文章，感觉不错。很多大咖都介绍了活化酵母的问题，但是感觉没说透。看了这篇文章，明白了。而且对酵母有了更多的了解。 简单翻译，文字没有精雕细作，仅供参考。 DRT Yeast FAQ干酵母常见问题
How should I store dry yeast?如何储藏干酵母
For long term storage, it is best to store dry yeast in a refrigerator. Overtime, dry yeast will naturally lose some viability, but it loses less at coldtemperatures than it does at warm temperatures. You can safely store dry yeastfor a year or longer at refrigerator temperatures without substantial loss inviability. 长期存放的话，最好把干酵母放在冰箱里。随着时间流逝，干酵母自然丧失一些活性，但是在低温中比在高温中丧失更少。在冰箱温度存放干酵母时间可以长达一年或更长，而不显著丧失活性。 When you decide to use the yeast, you should allow it tocome to room temperature before rehydrating so it does not experience a thermalshock. 当决定使用酵母时，应在活化之前应先让其达到室温，这样酵母不会遭遇热冲击（温度急升）。 Do I need to rehydrate dry yeast before pitching into mywort?投入麦汁前，需要活化干酵母吗？ In a word: yes. If you don't rehydrate your dry yeastbefore pitching, you may end up killing 50% of the yeast in the package whichcould increase both lag time and the risk of other bugs growing a strongercolony in your wort. The remaining yeast will be stressed, increasing thechance that you will notice off-flavors in your final product. Further, theremaining yeast will need to divide more times to reach the ideal colony size,virtually guaranteeing a greater presence of ester flavors. 简而言之：是。投入麦汁前如果不活化干酵母，可能会杀死一包酵母的50%，这将发酵延迟，增加麦汁中其他杂菌增长的风险。你会发现剩下的酵母会被增强，增加最终产品中异味的机会。不仅如此，剩下的酵母需要时间繁殖到理想的数量，无形中增加了酯类的存在。 When the yeast cell is first rehydrated, it has no way tocontrol what it absorbs or what leaches out of it. It needs a chance to rebuildits cell walls before it control those things. By adding the yeast directly tothe wort (effectively rehydrating it in wort), the yeast cell will be floodedwith sugars and other compounds that it isn't ready to process. 当酵母首次活化，他无法控制吸收什么或者释放什么。在取得控制权钱，他需要重建细胞墙。直接将酵母投入麦芽汁（有效在麦汁中活化），酵母细胞被糖和其他成分等包围，而酵母还没有做好准备。 How do I properly rehydrate dry yeast?如果合理活化干酵母
From “Yeast” by Chris White and Jamil Zainasheff:根据Chris White andJamil Zainasheff《酵母》一书 Quote:引用 | Every yeast strain has its own optimum rehydration process, but the basic procedure is as follows: 每种酵母都有自己最佳的活化过程。但是基本程序如下： 1. Warm the dry yeast to room temperature. 1.干酵母恢复室温
2. In a sanitized container, prepare an amount of sterile tap water at 105*F (41*C) equal to 10 times the weight of the yeast (10 ml/g of yeast). 2.在消毒容器中，准备一定量（10倍于酵母或者10ml/g）41摄氏度无菌水 3. Sprinkle the dry yeast on top of the water, trying to avoid setting up large, dry clumps. Let it sit for 15 minutes, then gently stir. 3. 将干酵母洒在水面上，尽量避免出现大的干燥的块状物。 静置15分钟，然后轻轻搅拌。 4. Once the yeast has reconstituted, gentle stir once again to form a cream, and let sit for another 5 minutes. 4.一旦酵母激活，再次温和搅拌形成酵母液，再放置5分钟。 5. Carefully and slowly, adjust the temperature of the yeast to within 15*F (8*C) of the wort temperature. 5.仔细和缓慢地将酵母的温度调节到麦芽汁温度的15 * F（8 * C）以内。 6. Pitch the resultant cream into the fermentation vessel, ideally as soon as possible. 6.将酵母液投入发酵容器中，越快越好。 |
How quickly do I need to pitch yeast once it has beenrehydrated?酵母活化后，如何尽快投放酵母？
Once the dry yeast has been reconstituted, you have a window of time to pitchthe yeast with minimal risk of contamination that is dependent on temperature.If the yeast is being stored at 25C, you should pitch within 4 hours; at 20Cyou should pitch within 6 hours; at 4C you should pitch with 18 hours. 一旦干酵母被激活，投入酵母以尽可能较少污染的窗口时间取决于温度。如果酵母在25C温度保持，应4个小时内投放，20C保持，应6小时内投放，4C保持应18小时内投放。 Keep in mind, it is a best practice to pitch the yeast assoon as possible. During the first 30 minutes, the yeast is given a boost fromvital nutrients that are packaged with it to help energize the yeast as itenters into its growth phase. Waiting longer than the recommended 30 minutescauses the nutrients to be exhausted and the yeast will want to go dormant,increasing the chances that you'll see a longer lag time when you pitch it. 记住：尽可能早地投放酵母是最好的做法。 在最初的30分钟内，酵母依靠与其一起包装的必要营养物一起迅速繁殖，以帮助酵母进入生长期。 等待推荐30分钟以上的时间会导致营养物质耗尽，并且酵母将休眠，增加投放后的延迟时间。
Can I re-use dry yeast?我能重新使用干酵母吗？ Yes, after fermentation is complete it can be harvestedjust like liquid yeast. There are lots of resources available on HBT aboutharvesting and also rinsing yeast, like this illustrated thread. Just as with anyyeast harvested for reuse, it is important to be aware of the viability of youryeast slurry in order to predict an accurate pitch rate. While that fallsoutside the scope of this FAQ, you may consider consulting pitching ratecalculators like Mr. Malty or YeastCalc or use othermeans as you see fit to ensure you pitch enough slurry or make a starter topropagate the right amount of yeast. 当然。发酵结束后，可以入液体酵母一般收集。在HBT上具有很多关于收集酵母同时清洗酵母的资源。
What are the disadvantages of using dry yeast?使用干酵母的缺点是什么 The biggest one is limited selection: there is a farbigger variety or liquid yeasts.
最大的是有限的选择：具有更多的种类或者液体酵母
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发表于 2017-7-3 17:02:45
